| sequencing of a 9.9 kb segment on the right arm of yeast chromosome vii reveals four open reading frames, including pfk1, the gene coding for succinyl-coa synthetase (beta-chain) and two orfs sharing homology with orfs of the yeast chromosome viii. | a 9.9 kb dna fragment from the right arm of chromosome vii of saccharomyces cerevisiae has been sequenced and analysed. the sequence contains four open reading frames (orfs) longer than 100 amino acids. one gene, pfk1, has already been cloned and sequenced and the other one is the probable yeast gene coding for the beta-subunit of the succinyl-coa synthetase. the two remaining orfs share homology with the deduced amino acid sequence (and their physical arrangement is similar to that) of the yhr1 ... | 1997 | 9090057 |
| identification of a drosophila 60s ribosomal protein. | we have previously reported the cloning and sequencing of a cdna from drosophila (dl43; genbank accession # u40226) which predicts a small protein homologous to a ribosomal protein in yeast and rat. in this study we show that a 330 nucleotide transcript encoding the putative ribosomal protein is expressed in drosophila kc cells under normal growth conditions (25 degrees c). this rna is associated with the translational machinery and is present on polysomes. the dl43 cdna was transcribed using t7 ... | 1997 | 9090117 |
| molecular evolution of cytochrome c oxidase subunit iv: evidence for positive selection in simian primates. | cytochrome c oxidase (cox) is a multi-subunit enzyme complex that catalyzes the final step of electron transfer through the respiratory chain on the mitochondrial inner membrane. up to 13 subunits encoded by both the mitochondrial (subunits i, ii, and iii) and nuclear genomes occur in eukaryotic organisms ranging from yeast to human. previously, we observed a high number of amino acid replacements in the human cox iv subunit compared to mouse, rat, and cow orthologues. here we examined cox iv ev ... | 1997 | 9115172 |
| characterization of a sphingomyelinase activity in saccharomyces cerevisiae. | sphingomyelinases (smase), which hydrolyze sphingolipids to yield ceramide, participate in signal transduction pathways in mammalian cells. although yeast express many homologs of mammalian signaling proteins, smase activity had not been previously demonstrated in yeast. in this study, we used an in vitro assay to characterize yeast smase activity. activity was detected in yeast membranes at both acid and neutral ph. the enzyme exhibited a requirement for magnesium or manganese, and was sensitiv ... | 1997 | 9126282 |
| identification of preussin as a selective inhibitor for cell growth of the fission yeast ts mutants defective in cdc2-regulatory genes. | | 1997 | 9127201 |
| position-independent and high-level expression of human alpha-lactalbumin in the milk of transgenic rats carrying a 210-kb yac dna. | the level of expression of transgenes in transgenic animals varies among lines, and is often much lower than that of endogenous genes (position effects). in order to surmount position effects and establish a more efficient production system of transgenic animals producing pharmaceutical proteins in their milk, transgenic rats carrying 210-kb yac dna containing the human alpha-lactalbumin gene were produced. three transgenic lines transmitted the transgene to the next generation. they had one cop ... | 1997 | 9136116 |
| [the antimutagenic action of apiculture products]. | using the battery of test-systems, we studied the possible antimutagenic activity of some products of apiculture. it is established that apilak-preparation made on the basis of queen bee milk didn't show gene-protective abilities in ames test. the rest products of apiculture: propolis, beebread, honey preparations n1 and n2, and queen bee milk manifested to some degree their ability to decrease the mutagenic effects of some chemical and physical mutagens. the toxic effect of propolis upon yeast ... | 1996 | 9139438 |
| essential role for diacylglycerol in protein transport from the yeast golgi complex. | yeast phosphatidylinositol transfer protein (sec14p) is required for the production of secretory vesicles from the golgi. this requirement can be relieved by inactivation of the cytosine 5'-diphosphate (cdp)-choline pathway for phosphatidylcholine biosynthesis, indicating that sec14p is an essential component of a regulatory pathway linking phospholipid metabolism with vesicle trafficking (the sec14p pathway). sac1p (refs 7 and 8) is an integral membrane protein related to inositol-5-phosphatase ... | 1997 | 9139830 |
| differential inhibition of fungal amd mammalian squalene epoxidases by the benzylamine sdz sba 586 in comparison with the allylamine terbinafine. | the allylamine class of antifungal compounds are specific inhibitors of squalene epoxidase (se). however, depending on their chemical structure, allylamine derivatives can be highly selective for either fungal or mammalian ses. all allylamines tested previously, irrespective of their selectivity, inhibit fungal ses in a noncompetitive manner and mammalian ses in a competitive manner. here we have analyzed the inhibitory properties of the benzylamine sdz sba 586 toward fungal and mammalian ses in ... | 1997 | 9143330 |
| anticryptococcal activity by alveolar macrophages from rats treated with cortisone acetate during different periods of time. | the effect of cortisone acetate (ca) treatment on the anticryptococcal activity by rat alveolar macrophages (am) was investigated. the animals received a weekly dose of 5 mg ca during 1, 2, 3 or 4 weeks. following the final dose the am were collected by lung lavage and challenged with cryptococcus neoformans. parallel experiments with silica particles of a similar size were performed. the phagocytic function was assessed using a fluorescence method that distinguishes between attached and ingeste ... | 1996 | 9144951 |
| [detectability and diagnostic criteria of p53 gene mutations in human oral squamous cell carcinoma using yeast functional assay]. | in yeast functional assay (yf assay), a newly developed screening system for p53 mutation, wild-type p53 gives white yeast colonies and transcriptionally inactive mutant p53 gives red colonies. in the present study, the author applied yf assay to the detection of p53 mutations in human oral squamous cell carcinoma (scc). total rna was extracted from samples and yf assay was performed. four scc cell lines (sas, hsc-2, hsc-3 and ca9-22) known to have p53 mutations all gave 100% red colonies, where ... | 1997 | 9145313 |
| the polymyositis-scleroderma autoantigen interacts with the helix-loop-helix proteins e12 and e47. | the basic helix-loop-helix (bhlh) transcription factors e12 and e47 regulate cellular differentiation and proliferation in diverse cell types. while looking for proteins that bind to e12 and e47 by the yeast interaction trap, we isolated the rat (r) homologue of the human (h) polymyositis-scleroderma autoantigen (pm-scl), which has been localized to the granular layer of the nucleolus and to distinct nucleocytoplasmic foci. the rpm-scl and hpm-scl homologues are 96% similar and 91% identical. we ... | 1997 | 9148967 |
| cdc42 regulates anchorage-independent growth and is necessary for ras transformation. | the rho family members cdc42, rac, and rho play a central role in the organization of the actin cytoskeleton and regulate transcription. whereas rac and rho have been implicated in transformation by oncogenic ras, the role of cdc42 in this process remains unknown. in this study, we found that rat1 fibroblasts expressing constitutively active v12-cdc42 were anchorage independent and proliferated in nude mice but failed to show enhanced growth in low serum. similar to v12-rac1-expressing rat1 fibr ... | 1997 | 9154844 |
| nup84, a novel nucleoporin that is associated with can/nup214 on the cytoplasmic face of the nuclear pore complex. | the short filaments extending from the cytoplasmic face of nuclear pore complexes are thought to contain docking sites for nuclear import substrates. one component of these filaments is the large o-linked glycoprotein can/nup214. immunoprecipitation studies carried out under nondenaturing conditions, and using a variety of antibodies, reveal a novel nonglycosylated nucleoporin, nup84, that is tightly associated with can/nup214. consistent with such an association, nup84 is found to be exposed on ... | 1997 | 9166401 |
| a novel structural model for regulation of clathrin function. | the distinctive triskelion shape of clathrin allows assembly into polyhedral lattices during the process of clathrin-coated vesicle formation. we have used random and site-directed mutagenesis of the yeast clathrin heavy chain gene (chc1) to characterize regions which determine chc trimerization and binding to the clathrin light chain (clc) subunit. analysis of the mutants indicates that mutations in the trimerization domain at the triskelion vertex, as well as mutations in the adjacent leg doma ... | 1997 | 9171338 |
| transcriptional activation of the human estrogen receptor by ddt isomers and metabolites in yeast and mcf-7 cells. | in this study, we determined whether the ddt isomers p,p'-ddt [1,1,1,-trichloro-2,2-bis(p-chlorophenyl)ethane], o,p'-ddt [1,1,1-trichloro-2(p-chlorophenyl)-2-(o-chlorophenyl)ethane], and their metabolites p,p'-ddd [1,1-dichloro-2,2-bis(p-chlorophenyl)ethane], o,p'-ddd [1,1-dichloro-2-(p-chlorophenyl)-2-(o-chlorophenyl)ethane], p,p'-dde [1,1,-dichloro-2,2-bis(p-chlorophenyl)ethylene], o,p'-dde [1,1-dichloro-2-(p-chlorophenyl)-2-(o-chlorophenyl)ethylene], and p,p'-dda [2,2-bis(p-chlorophenyl)aceti ... | 1997 | 9175721 |
| amino acids val115-ile126 of rat gastric h(+)-k(+)-atpase confer high affinity for sch-28080 to na(+)-k(+)-atpase. | na(+)-k(+)-atpase is inhibited by cardiac glycosides and is insensitive to sch-28080, an inhibitor of gastric h(+)-k(+)-atpase. gastric h(+)-k(+)-atpase is not inhibited by cardiac glycosides. both ouabain and, sch-28080 binding are inhibited by k+, and it has been suggested that the inhibitors bind to corresponding regions on the alpha-subunit of each ion pump. for identification of regions of each pump that interact with the specific inhibitors, chimeric alpha-subunits consisting of selected r ... | 1997 | 9176164 |
| the rodent uterotrophic assay: critical protocol features, studies with nonyl phenols, and comparison with a yeast estrogenicity assay. | the major protocol features of the immature rat uterotrophic assay have been evaluated using a range of reference chemicals. the protocol variables considered include the selection of the test species and route of chemical administration, the age of the test animals, the maintenance diet used, and the specificity of the assay for estrogens. it is concluded that three daily oral administrations of test chemicals to 21- to 22-day-old rats, followed by determination of absolute uterus weights on th ... | 1997 | 9185893 |
| detection of erk activation by a novel monoclonal antibody. | the mitogen-activated protein kinase, erk is activated by a dual phosphorylation on threonine and tyrosine residues. using a synthetic diphospho peptide, we have generated a monoclonal antibody directed to the active erk. the antibody specifically identified the active doubly phosphorylated, but not the inactive mono- or non- phosphorylated forms of erks. a direct correlation was observed between erk activity and the intensity in western blot of mitogen-activated protein kinases from several spe ... | 1997 | 9188779 |
| novel prodrugs of cyanamide that inhibit aldehyde dehydrogenase in vivo. | s-methylisothiourea (4), when administered to rats followed by a subsequent dose of ethanol, gave rise to a 119-fold increase in ethanol-derived blood acetaldehyde (ach) levels-a consequence of the inhibition of hepatic aldehyde dehydrogenase (a1dh)-when compared to control animals not receiving 4. the corresponding o-methylisourea was totally inactive under the same conditions, suggesting that differential metabolism may be a factor in this dramatic difference between the pharmacological effect ... | 1997 | 9191964 |
| the hepatitis b virus x-associated protein, xap3, is a protein kinase c-binding protein. | the hepatitis b virus x protein induces transcriptional activation of a wide variety of viral and cellular genes. in addition to its ability to interact directly with many nuclear transcription factors, several reports indicate that the x protein stimulates different cytoplasmic kinase signal cascades. using the yeast two-hybrid screen, we have isolated a clone designated x-associated protein 3 (xap3) that encodes a human homolog of the rat protein kinase c-binding protein. one of the activation ... | 1997 | 9195957 |
| tolerance of low ph in schizosaccharomyces pombe requires a functioning pub1 ubiquitin ligase. | a strain of schizosaccharomyces pombe carrying a disrupted na+/h+ antiporter gene (sod2::sup3-5), in addition to the common auxotrophic mutations, ade6-216, ura4-d18 and leu1-32, is highly sensitive to media adjusted to ph 6.9. reversion analysis of this strain yielded a group of revertants capable of growth at ph 6.9. two of the revertants elongated and failed to form colonies at ph 3.5. genetic characterization of one of the ph-sensitive elongated strains, j227, showed the presence of two inde ... | 1997 | 9197411 |
| mitogen-activated and cyclin-dependent protein kinases selectively and differentially modulate transcriptional enhancement by the glucocorticoid receptor. | cyclin-dependent kinase (cdk) and mitogen-activated protein kinase (mapk) phosphorylate the rat glucocorticoid receptor in vitro at distinct sites that together correspond to the major phosphorylated receptor residues observed in vivo; mapk phosphorylates receptor residues threonine 171 and serine 246, whereas multiple cdk complexes modify serines 224 and 232. mutations in these kinases have opposite effects on receptor transcriptional activity in vivo. receptor-dependent transcriptional enhance ... | 1997 | 9199329 |
| molecular cloning of htra2-beta-1 and htra2-beta-2, two human homologs of tra-2 generated by alternative splicing. | a yeast two-hybrid screen was performed to find new factors involved in pre-mrna splicing. using sc35 as a bait, we isolated a human cdna bearing high homology to the drosophila transformer-2 (tra-2) protein. this cdna was named htra2-beta1. htra2-beta1 is a nuclear protein that colocalizes with sc35 in a speckled pattern. it interacts with several sr proteins tested in yeast. a second form named htra2-beta2 is generated by alternative splicing. this isoform gives rise to a truncated protein wit ... | 1997 | 9212162 |
| studies on anti-inflammatory agents. iv. synthesis and pharmacological properties of 1,5-diarylpyrazoles and related derivatives. | a series of novel 1,5-diarylpyrazole derivatives was synthesized and tested for anti-inflammatory and analgesic activities to develop anti-inflammatory agents with fewer side effects than existing nonsteroidal anti-inflammatory drugs. the structure-activity relationships in this series were extensively studied. electron-withdrawing substituents such as cn and cf3 were optimal at the 3-position of the pyrazole ring. replacement of these substituents with bulky ones gave less active compounds. the ... | 1997 | 9214705 |
| characterization of translation initiation factor 5 (eif5) from saccharomyces cerevisiae. functional homology with mammalian eif5 and the effect of depletion of eif5 on protein synthesis in vivo and in vitro. | eukaryotic translation initiation factor 5 (eif5) interacts in vitro with the 40 s initiation complex (40 s.aug.met-trnaf.eif2.gtp) to mediate the hydrolysis of ribosome-bound gtp. in saccharomyces cerevisiae, eif5 is encoded by a single copy essential gene, tif5, that encodes a protein of 45,346 daltons. to understand the function of eif5 in vivo, we constructed a conditional mutant yeast strain in which a functional but a rapidly degradable form of eif5 fusion protein was synthesized from the ... | 1997 | 9218474 |
| analysis of the functional domain of the rat liver mitochondrial import receptor tom20. | tom20 is an outer mitochondrial membrane protein and functions as a component of the import receptor complex for the cytoplasmically synthesized mitochondrial precursor proteins. it consists of the n-terminal membrane-anchor segment, the tetratricopeptide repeat (tpr) motif, a charged amino acids-rich linker segment between the membrane anchor and the tpr motif, and the c-terminal acidic amino acid cluster. to assess the functional significance of these segments in mammalian tom20, we cloned rat ... | 1997 | 9218491 |
| purification and partial sequencing of the xl-i form of xenobiotic-metabolizing medium chain fatty acid:coa ligase from bovine liver mitochondria, and its homology with the essential hypertension protein. | the xl-i form of xenobiotic-metabolizing medium-chain fatty acid:coa ligase was purified to apparent homogeneity from bovine liver mitochondria. the procedure gave rise to a 435-fold increase in specific activity, with a yield of 12%. the enzyme eluted from a gel filtration column as a single peak with an apparent molecular weight of ca. 55,000. it ran as a single band on sds-polyacrylamide gel electrophoresis (sds-page) which had an apparent molecular weight of 62 kda. n-terminal sequence analy ... | 1997 | 9219907 |
| establishment of a novel host, high-red yeast that stably expresses hamster nadph-cytochrome p450 oxidoreductase: usefulness for examination of the function of mammalian cytochrome p450. | a novel strain of saccharomyces cerevisiae useful for expression studies of mammalian microsomal cytochrome p450s was established and named high-red yeast. hamster nadph-cytochrome p450 oxidoreductase (p450 reductase) cdna to be introduced into yeast was isolated from a hamster liver cdna library. the cdna was 2421 bp long and contained an entire coding region for 667 amino acids. the nh2-terminal amino acid sequence deduced from the hamster p450 reductase cdna was identical with that of the enz ... | 1997 | 9224733 |
| response of the germfree rat colonic mucosa to dietary endotoxins. | suggestive to induce an immunoreactive response in the colon mucosa of germfree rats 3 diets, autoclaved or gamma-irradiated, respectively, were administered to groups of 30 days old gf ztm:sprd rats. diets and rats were studied in parallel after a feeding period of 20 days. the microbiological controls confirmed the sterility of diets and animals. the aqueous suspensions of one diet displayed obviously dead yeast and gram positive and negative bacteria, which consistently were evident in coloni ... | 1996 | 9226963 |
| fatty acyl-coa-acyl-coa-binding protein complexes activate the ca2+ release channel of skeletal muscle sarcoplasmic reticulum. | we previously reported that fatty acyl-coa esters activate ryanodine receptor/ca2+ release channels in a terminal cisternae fraction from rabbit skeletal muscle [fulceri, nori, gamberucci, volpe, giunti and benedetti (1994) cell calcium 15, 109-116]. skeletal muscle cytosol contains a high-affinity fatty acyl-coa-binding protein (acbp) [knudsen, hojrup, hansen, h.o., hansen, h.f. and roepstorff (1989) biochem. j. 262, 513-519]. we show here that palmitoyl-coa (pcoa) in a complex with a molar exc ... | 1997 | 9230123 |
| mis6, a fission yeast inner centromere protein, acts during g1/s and forms specialized chromatin required for equal segregation. | disorder in sister chromatid separation can lead to genome instability and cancer. a temperature-sensitive s. pombe mis6-302 frequently loses a minichromosome at 26 degrees c and abolishes equal segregation of regular chromosomes at 36 degrees c. the mis6+ gene is essential for viability, and its deletion results in missegregation identical to mis6-302. mis6 acts before or at the onset of s phase, and mitotic missegregation defects are produced only after the passage of g1/s at 36 degrees c. mis ... | 1997 | 9230309 |
| phosphoinositolglycan-peptides from yeast potently induce metabolic insulin actions in isolated rat adipocytes, cardiomyocytes, and diaphragms. | polar headgroups of free glycosyl-phosphatidylinositol (gpi) lipids or protein-bound gpi membrane anchors have been shown to exhibit insulin-mimetic activity in different cell types. however, elucidation of the molecular mode of action of these phospho-inositolglycan (pig) molecules has been hampered by 1) lack of knowledge of their exact structure; 2) variable action profiles; and 3) rather modest effects. in the present study, these problems were circumvented by preparation of pig-peptides (pi ... | 1997 | 9231801 |
| cloning and expression of the delta 9 fatty acid desaturase gene from cryptococcus curvatus atcc 20509 containing histidine boxes and a cytochrome b5 domain. | to allow genetic modification of the fatty acid biosynthesis routes in the lipid-accumulating yeast cryptococcus curvatus the delta 9 fatty acid desaturase gene was cloned and characterized. the 1668-bp gene encodes a protein of 556 amino acids with a calculated molecular mass of 62 kda. the gene shows strong homology to previously cloned delta 9 fatty acid desaturase genes from yeast and rat. homology includes three histidine boxes characteristic for membrane-bound desaturases and a cytochrome ... | 1997 | 9237389 |
| binding of mitochondrial precursor proteins to the cytoplasmic domains of the import receptors tom70 and tom20 is determined by cytoplasmic chaperones. | we have reconstituted the early steps of precursor targeting to mitochondria in a defined and soluble system consisting of the cytosolic domains of the yeast mitochondrial import receptors tom20 and tom70, precursor to bovine adrenal adrenodoxin (which has a cleavable targeting signal) and rat liver cytosolic chaperones hsp70 and mitochondrial import-stimulating factor (msf). the tom70 domain only bound the precursor in the presence of msf, yielding a precursor-msf-tom70 complex; atp hydrolysis ... | 1997 | 9250670 |
| use of conditional promoters for expression of heterologous proteins in saccharomyces cerevisiae. | | 1997 | 9251029 |
| identification and cloning of the human homolog (jag1) of the rat jagged1 gene from the alagille syndrome critical region at 20p12. | notch proteins are a family of closely related transmembrane receptors proven to be instrumental in cell fate decisions. recently, notch ligands delta and jagged have been identified in drosophila and rat, respectively. we have isolated the human homolog of the rat jagged1 gene, jag1, from a cpg island in a yac clone covering the alagille syndrome critical region at chromosome 20p12 (tel-snap-d20s186-cen). alagille syndrome is an autosomal dominant disorder characterized by neonatal jaundice, pa ... | 1997 | 9268641 |
| purification of alcohol dehydrogenase from entamoeba histolytica and saccharomyces cerevisiae using zinc-affinity chromatography. | we have developed a single-step method for the purification of nadp(+)-dependent alcohol dehydrogenase from entamoeba histolytica and nad(+)-dependent alcohol dehydrogenase from saccharomyces cerevisiae. it is based on the affinity for zinc of both enzymes. the amebic enzyme was purified almost 800 times with a recovery of 54% and the yeast enzyme was purified 30 times with a recovery of 100%. the kinetic constants of the purified enzymes were similar to those reported for other purification met ... | 1997 | 9268681 |
| a critical amino acid residue, asp446, in udp-glucuronosyltransferase. | an amino acid residue, asp446, was found to be essential for the enzymic activity of udp-glucuronosyltransferase (ugt). we obtained a rat phenol ugt (ugt1*06) cdna (named ysh) from male rat liver by reverse-transcription (rt)-pcr using pfu polymerase. a mutant ysh having two different bases, a1337g and g1384a (named ysh a1337gc1384a), that result in two amino acid substitutions, d446g and v462m, was obtained by rt-pcr using taq polymerase. ysh was expressed functionally in microsomes of saccharo ... | 1997 | 9271076 |
| a novel murine p-450 gene, cyp4a14, is part of a cluster of cyp4a and cyp4b, but not of cyp4f, genes in mouse and humans. | genomic clones for cyp4a12 and a novel member of the murine cyp4a gene family were isolated. the novel gene, designated cyp4a14, has a gc rich sequence immediately 5' of the transcription start site, and is similar to the rat cyp4a2 and cyp4a3 genes. the cyp4a14 gene spans approximately 13 kb, and contains 12 exons; sequence similarity to the rat cyp4a2 gene sequence falls off 300 bp upstream from the start site. in view of the known sex-specific expression of the rat cyp4a2 gene, the expression ... | 1997 | 9271096 |
| deletion of the yeast homologue of the human gene associated with friedreich's ataxia elicits iron accumulation in mitochondria. | deletion of ydl120, the yeast homologue of the human gene responsible for friedreich's ataxia, elicits decreased cellular respiration associated with decreased cytochrome c oxidase activity and, in certain nuclear backgrounds, mitochondrial dna is lost. in the null mutants, the cellular growth is highly sensitive to oxidants, such as h2o2, iron and copper. however, only ferrous sulfate elicits loss of mitochondrial dna. mitochondria of the null mutants contain 10 times more iron than wild-type. ... | 1997 | 9271239 |
| positive and negative regulation of gene expression in eukaryotic cells with an inducible transcriptional regulator. | to facilitate the understanding of the complex process of target gene expression and its control, we report a modified inducible system for activation or repression of target gene expression in response to an exogenously administered compound. the main component of this inducible system is a chimeric transcriptional activator (glvp) consisting of an n-terminal vp16 transcriptional activation domain fused to a yeast gal4 dna binding domain and a mutated human progesterone receptor (hpr) ligand bi ... | 1997 | 9274720 |
| identification and characterization of the af-1 transactivation domain of thyroid hormone receptor beta1. | physiological responses to thyroid hormones are regulated by a set of nuclear receptors (trs) related to the steroid receptor superfamily of ligand-dependent transcription factors. although tr isoforms are highly conserved in their dna binding, ligand binding, and carboxyl-terminal transactivation domains, their amino-terminal regions are completely divergent. we examined the contribution of these amino-terminal sequences to trbeta1 function. an amino-terminally truncated version of rat trbeta1 ... | 1997 | 9295330 |
| [comparative analysis of primary structures of yeast dolicholphosphomannosyl- and dolichophosphoglucosyl synthetases and other dolichol-conjugated enzymes]. | primary structure of yeast dolicholphosphomannosyl- (dpms) and dolicholphosphoglucosylsynthetases (dpgs) have been compared both between themselves and dpms and dpgs with yeast beta- and alpha-1, 3-mannosyltransferases, glucosyltransferases and rat mannosyl-binding proteins. the long homological segments were revealed. the homological segments of beta- and alpha-1, 3-mannosyltransferases were located in regions having potency to form coiled-coil structures. these structures are known to be inclu ... | 1996 | 9297302 |
| identification of a new cellular protein that can interact specifically with dan. | recently, we demonstrated that the dan gene product contains a growth- and/or a tumor-suppressive activity in vitro. in the present work, using a yeast two-hybrid system, we searched for cellular proteins that can associate with the dan gene product. a cdna clone, termed da41, was initially isolated from an adult rat lung cdna library. the da41 gene was expressed in all adult tissues examined, however, the levels of expression varied significantly among the different tissues. like the dan gene p ... | 1997 | 9303440 |
| evaluation of the antiinflammatory activity of sodium valproate in rats and mice. | 1. treatment of rats with sodium valproate (100, 200 and 400 mg/kg i.p.) reduced the paw oedema induced by carrageenan by 36, 15 and 48%, respectively, within 3 h . 2. the effect produced by the higher dose (400 mg/kg) was equivalent to that produced by indomethacin (100 mg/kg). at 100 and 400 mg/kg, sodium valproate decreased the granuloma formation by a significant level. similar doses of sodium valproate did not affect the rectal temperature in yeast-fevered mice, except with a dose of 200 mg ... | 1996 | 9304414 |
| uncoupling protein-3 is a mediator of thermogenesis regulated by thyroid hormone, beta3-adrenergic agonists, and leptin. | mitochondrial uncoupling proteins (ucps) are transporters that are important for thermogenesis. the net result of their activity is the exothermic movement of protons through the inner mitochondrial membrane, uncoupled from atp synthesis. we have cloned a third member of the ucp family, ucp3. ucp3 is expressed at high levels in muscle and rodent brown adipose tissue. overexpression in yeast reduced the mitochondrial membrane potential, showing that ucp3 is a functional uncoupling protein. ucp3 r ... | 1997 | 9305858 |
| an isoform of the golgi t-snare, syntaxin 5, with an endoplasmic reticulum retrieval signal. | the early golgi t-snare (target-membrane-associated soluble-n-ethylmaleimide-sensitive factor attachment protein receptor) syntaxin 5 is thought to specify the docking site for both copi and copii coated vesicles originating from the endoplasmic reticulum (er) and copi vesicles on the retrograde pathway. we now show that there are two forms of syntaxin 5 that appear to be generated from the same mrna by alternative initiation of translation. the short form (35 kda) corresponds to the published s ... | 1997 | 9307973 |
| inhibitory effect of human natural yeast killer toxin-like candidacidal antibodies on pneumocystis carinii. | human natural antibodies have been found that owe their candidacidal action to the mimicry of a yeast killer toxin produced by the yeast pichia anomala (pakt). candidacidal human natural antibodies (ktab) are elicited by and bind to a kt receptor (paktr) present on the cell surface of infectious pakt-sensitive microorganisms. because of the recognized susceptibility of pneumocystis carinii organisms to pakt upon the occurrence of specific paktr, we examined whether human natural ktab could also ... | 1997 | 9307982 |
| identification by site-directed mutagenesis of three arginines in uncoupling protein that are essential for nucleotide binding and inhibition. | primary regulation of uncoupling protein is mediated by purine nucleotides, which bind to the protein and allosterically inhibit fatty acid-induced proton transport. to gain increased understanding of nucleotide regulation, we evaluated the role of basic amino acid residues using site-directed mutagenesis. mutant and wild-type proteins were expressed in yeast, purified, and reconstituted into liposomes. we studied nucleotide binding as well as inhibition of fatty acid-induced proton transport in ... | 1997 | 9312070 |
| a unique role of the beta-2 thyroid hormone receptor isoform in negative regulation by thyroid hormone. mapping of a novel amino-terminal domain important for ligand-independent activation. | negative regulation by thyroid hormone is mediated by nuclear thyroid hormone receptors (trs) acting on thyroid hormone response elements (tres). we examine here the role of human tr-beta2, a tr isoform with central nervous system-restricted expression, in the regulation of target genes whose expression are decreased by triiodothyronine (t3). using transient transfection studies, we found that tr-beta2 achieved significantly greater ligand-independent activation on the thyrotropin-releasing horm ... | 1997 | 9312095 |
| development of a tier i screening battery for detecting endocrine-active compounds (eacs) | one of the components of our research program is development of a mode-of-action screening battery to detect several different types of endocrine-active compounds (eacs). our working hypothesis is that a comprehensive short-term in vivo/in vitro battery can be developed to identify endocrine toxicants using a collection of endpoints. the goals of this battery are that it be quick, cost effective, and predictive. the purpose of this battery is to identify potential eacs and to assess their potenc ... | 1997 | 9325205 |
| failure to confirm estrogenic activity for benzoic acid and clofibrate: implications for lists of endocrine-disrupting agents | earlier reports that benzoic acid is uterotrophic to the rat and mouse and that clofibrate is uterotrophic to the rat have not been confirmed. the studies reported here involved the use of a range of test protocols and dose levels, including the protocols/dose levels used by the original investigators. in addition, both chemicals were inactive in a human estrogen receptor (heralpha) yeast estrogenicity assay. it is concluded that benzoic acid and clofibrate are not estrogenic in the assays used ... | 1997 | 9325211 |
| potassium collapses the deltap in yeast mitochondria while the rate of atp synthesis is inhibited only partially: modulation by phosphate. | addition of increasing concentrations of k+ to yeast mitochondria in the presence of 0 to 400 microm phosphate and 200 microm mg2+ led to uncoupled respiration and decreased protonmotive force (deltap):at 0 k+ deltap = 213 mv, negative inside, where deltapsi = 180 mv and deltaph = 33 mv, while at 20 mm k+ deltap = 28 mv, where deltapsi = 16 mv and deltaph = 12 mv. in contrast, the synthesis of atp resulted in smaller values for the km and the vmax in 400 microm pi and increasing adp: in 0 k+, km ... | 1997 | 9328282 |
| cloning of a human multispanning membrane protein cdna: evidence for a new protein family. | we report the cloning of a human cdna encoding a protein of calculated 68.8 kda molecular mass, named hmp70. the deduced protein sequence shows a large n-terminal hydrophilic part and a c-terminal part with nine putative hydrophobic regions characteristic of integral transmembrane domains. computer searches with sequence databases revealed homologies with three complete yeast proteins and with at least 19 human, 10 plant and one nematode short unidentified protein sequences translated from expre ... | 1997 | 9332367 |
| the third member of the tetrahymena cct subunit gene family, tpcct alpha, encodes a component of the hetero-oligomeric chaperonin complex. | the sequence of a third member of the tetrahymena pyriformis chaperonin cct ('chaperonin containing tcp1') subunit gene family is presented. this gene, designated tpcct alpha, is the orthologue of the mouse chaperonin gene tcp1/cct alpha. to characterize the cct complex in this ciliate, we have produced polyclonal antibodies against synthetic peptides based on c-terminal sequences deduced from the primary sequences of the tpcct alpha, tpcct gamma and tpcct eta subunits. we have also used polyclo ... | 1997 | 9337846 |
| development of a tier i screening battery for detecting endocrine-active compounds (eacs). | one of the components of our research program is development of a mode-of-action screening battery to detect several different types of endocrine-active compounds (eacs). our working hypothesis is that a comprehensive short-term in vivo/in vitro battery can be developed to identify endocrine toxicants using a collection of endpoints. the goals of this battery are that it be quick, cost effective, and predictive. the purpose of this battery is to identify potential eacs and to assess their potenc ... | 1997 | 9339481 |
| failure to confirm estrogenic activity for benzoic acid and clofibrate: implications for lists of endocrine-disrupting agents. | earlier reports that benzoic acid is uterotrophic to the rat and mouse and that clofibrate is uterotrophic to the rat have not been confirmed. the studies reported here involved the use of a range of test protocols and dose levels, including the protocols/dose levels used by the original investigators. in addition, both chemicals were inactive in a human estrogen receptor (her alpha) yeast estrogenicity assay. it is concluded that benzoic acid and clofibrate are not estrogenic in the assays used ... | 1997 | 9339486 |
| molecular cloning and nucleotide sequence of the arginase gene of bacillus brevis tt02-8 and its expression in escherichia coli. | the gene from bacillus brevis tt02-8 encoding arginase was cloned into escherichia coli, and its nucleotide sequence was identified. the nucleotide sequence contained an open reading frame that encoded a polypeptide of 298 amino acid residues with a predicted molecular weight of 31,891, which was consistent with that previously calculated for arginase purified from this bacterium. comparison of the deduced amino acid sequence of the b. brevis tt02-8 arginase with that of the prokaryotic and euka ... | 1997 | 9339546 |
| nitrobenzimidazoles as substrates for dt-diaphorase and redox cycling compounds: their enzymatic reactions and cytotoxicity. | we have synthesized a number of nitrobenzimidazoles containing nitro groups in the benzene ring and found that they acted as relatively efficient substrates for rat liver dt-diaphorase (ec 1.6.99.2), their reactivity exceeding reactivities of nitrofurans and nitrobenzenes. nitrobenzimidazoles were competitive with nadph inhibitors of dt-diaphorase in menadione reductase reactions, their inhibition constant being unchanged in the presence of dicumarol and being increased in the presence of 2',5'- ... | 1997 | 9343369 |
| functional studies of yeast-expressed human heart muscle carnitine palmitoyltransferase i. | long-chain fatty acids are the primary source of energy production in the heart. carnitine palmitoyltransferase i (cpt-i) catalyzes the first reaction in the transport of long-chain fatty acids from the cytoplasm to the mitochondrion, a rate-limiting step in beta-oxidation. in this study, we report the functional expression of the human heart/skeletal muscle isoform of cpt-i (m-cpt-i) in the yeast pichia pastoris. screening of a human heart cdna library with cdna fragments encoding the rat heart ... | 1997 | 9344464 |
| identification and subcellular localization of a novel mammalian dynamin-related protein homologous to yeast vps1p and dnm1p. | the dynamin family of gtp-binding proteins are implicated in vesicular transport. these include mammalian dynamins i, ii, iii, and yeast vps1p and dnm1p. dynamin is involved in the formation of clathrin-coated vesicles at the plasma membrane. on the other hand, vps1p and dnm1p appear to be involved in transport from the late golgi compartment to vacuoles and in an endocytic process, respectively. in this study, we identified a novel human protein, named dnm1p/vps1p-like protein (dvlp). it resemb ... | 1997 | 9348079 |
| nup93, a vertebrate homologue of yeast nic96p, forms a complex with a novel 205-kda protein and is required for correct nuclear pore assembly. | yeast and vertebrate nuclear pores display significant morphological similarity by electron microscopy, but sequence similarity between the respective proteins has been more difficult to observe. herein we have identified a vertebrate nucleoporin, nup93, in both human and xenopus that has proved to be an evolutionarily related homologue of the yeast nucleoporin nic96p. polyclonal antiserum to human nup93 detects corresponding proteins in human, rat, and xenopus cells. immunofluorescence and immu ... | 1997 | 9348540 |
| effect of bcr sequences on the cellular function of the bcr-abl oncoprotein. | in philadelphia chromosome (ph1)-positive human leukemia, the c-abl tyrosine kinase is activated by fusion to sequences encoded by the breakpoint cluster region (bcr) gene. two major types of bcr-abl fusion proteins have been found in human leukemia. fusion of the n-terminal 426 amino acids of bcr generates p190(bcr-abl) which is mostly found in acute lymphocytic leukemia (all), whereas fusion of the n-terminal 902 or 927 amino acids of bcr generates p210(bcr-abl) mostly found with chronic myelo ... | 1997 | 9349495 |
| role of peroxynitrite and activation of poly (adp-ribose) synthase in the vascular failure induced by zymosan-activated plasma. | 1. zymosan is a wall component of the yeast saccharomyces cerevisiae. injection of zymosan into experimental animals is known to produce an intense inflammatory response. recent studies demonstrated that the zymosan-induced inflammatory response in vivo can be ameliorated by inhibitors of nitric oxide (no) biosynthesis. the cytotoxic effects of no are, in part, mediated by the oxidant preoxynitrite and subsequent activation of the nuclear enzyme poly (adp-ribose) synthetase (pars). in the presen ... | 1997 | 9351506 |
| the cerebellar leucine-rich acidic nuclear protein interacts with ataxin-1. | spinocerebellar ataxia type 1 (sca1) is an autosomal dominant neurodegenerative disorder characterized by ataxia, progressive motor deterioration, and loss of cerebellar purkinje cells. sca1 belongs to a growing group of neurodegenerative disorders caused by expansion of cag repeats, which encode glutamine. although the proteins containing these repeats are widely expressed, the neurodegeneration in sca1 and other polyglutamine diseases selectively involves a few neuronal subtypes. the mechanism ... | 1997 | 9353121 |
| promoter escape by rna polymerase ii. formation of an escape-competent transcriptional intermediate is a prerequisite for exit of polymerase from the promoter. | shortly after initiating promoter-specific transcription in vitro, mammalian rna polymerase ii becomes highly susceptible to arrest in a promoter-proximal region 9-13 base pairs downstream of the transcriptional start site (dvir, a., conaway, r. c., and conaway, j. w. (1996) j. biol. chem. 271, 23352-23356). arrest by polymerase in this region is suppressed by tfiih in an atp-dependent reaction (dvir, a., conaway, r. c., and conaway, j. w. (1997) proc. natl. acad. sci. u. s. a. 94, 9006-9010). i ... | 1997 | 9353262 |
| bok is a pro-apoptotic bcl-2 protein with restricted expression in reproductive tissues and heterodimerizes with selective anti-apoptotic bcl-2 family members. | in the intracellular death program, hetero- and homodimerization of different anti- and pro-apoptotic bcl-2-related proteins are critical in the determination of cell fate. from a rat ovarian fusion cdna library, we isolated a new pro-apoptotic bcl-2 gene, bcl-2-related ovarian killer (bok). bok had conserved bcl-2 homology (bh) domains 1, 2, and 3 and a c-terminal transmembrane region present in other bcl-2 proteins, but lacked the bh4 domain found only in anti-apoptotic bcl-2 proteins. in the ... | 1997 | 9356461 |
| regulation of inositol lipid-specific phospholipase cdelta by changes in ca2+ ion concentrations. | studies of inositol lipid-specific phospholipase c (plc) have elucidated the main regulatory pathways for plcbeta and plcgamma but the regulation of plcdelta isoenzymes still remains obscure. here we demonstrate that an increase in ca2+ ion concentration within the physiological range (0.1-10 microm) is sufficient to stimulate plcdelta1, but not plcgamma1 and plcbeta1, to hydrolyse cellular inositol lipids present in permeabilized cells. the activity of plcdelta1 is further enhanced in the prese ... | 1997 | 9359428 |
| mosquito clathrin heavy chain: analysis of protein structure and developmental expression in the ovary during vitellogenesis. | we have deduced the amino acid sequences of clathrin heavy chain (chc) polypeptides based on cdna and genomic clones from the mosquito, aedes aegypti. two isoforms which differ in the very beginning of the n-terminal domain, ovary-specific aachca and somatic-specific aachcb, were identified, characterized and compared to one another as well as to chc polypeptides from different species. the 1682 amino acid sequence of the aachca isoform predicts a molecular mass (m[r]) of 191,743 daltons and an ... | 1997 | 9359577 |
| noc2, a putative zinc finger protein involved in exocytosis in endocrine cells. | we have cloned a cdna encoding a novel protein of 302 amino acids (designated noc2, no c2 domain) that has 40.7% amino acid identity with and 77.9% similarity to the n-terminal region of rabphilin-3a, a target molecule of rab3a. however, unlike rabphilin-3a, noc2 lacks two c2 domains that are thought to interact with ca2+ and phospholipids. noc2 is expressed predominantly in endocrine tissues and hormone-secreting cell lines and at very low levels in brain. immunoblot analysis of subcellular fra ... | 1997 | 9367993 |
| interference of bad (bcl-xl/bcl-2-associated death promoter)-induced apoptosis in mammalian cells by 14-3-3 isoforms and p11. | apoptosis and survival of diverse cell types are under hormonal control, but intracellular mechanisms regulating cell death are unclear. the bcl-2/ced-9 family of proteins contains conserved bcl-2 homology regions that mediate the formation of homo- or heterodimers important for enhancing or suppressing apoptosis. unlike most other members of the bcl-2 family, bad (bcl-xl/bcl-2 associated death promoter), a death enhancer, has no c-terminal transmembrane domain for targeting to the outer mitocho ... | 1997 | 9369453 |
| expression cloning of a mammalian amino acid transporter or modifier by complementation of a yeast transport mutant. | a cdna clone named l21 was isolated from l6 rat muscle cells by complementation of a yeast proline transport mutant. l21 cdna has 2,268 bp and codes for a peptide of 228 amino acids with four potential transmembrane domains. the amino acid sequence of l21 shows no homology to any known proteins. expression of l21 cdna enables the mutant yeast to grow in proline as the sole nitrogen source and to transport proline, alpha-aminoisobutyric acid (aib) and leucine. the km for proline is about 1.0 mm. ... | 1997 | 9369948 |
| the phospholipid methyltransferases in yeast. | in fungal microorganisms including fission yeast, schizosaccharomyces pombe and baker's yeast, saccharomyces cerevisiae, two enzymes are required to catalyze the synthesis of phosphatidylcholine (pc) from phosphatidylethanolamine (pe). the genes encoding the class i and class ii phospholipid n-methyltransferases (plmts) have been cloned from both yeasts. the class ii plmts catalyze the first methylation step from pe to phosphatidyl-monomethylethanolamine (pmme). representatives of the class ii t ... | 1997 | 9370325 |
| identification and sequence of human pky, a putative kinase with increased expression in multidrug-resistant cells, with homology to yeast protein kinase yak1. | we have previously shown that several protein kinases are present in higher activity levels in multidrug resistant cell lines, such as kb-v1. we have now isolated a gene that codes for a putative protein kinase, pky, of over 130 kda that is expressed at higher levels in multidrug-resistant cells. rna from kb-v1 multidrug-resistant cells was reverse-transcribed and amplified by using primers derived from consensus regions of serine threonine kinases and amplified fragments were used to recover ov ... | 1997 | 9373137 |
| no evidence for involvement of mouse protein-tyrosine phosphatase-bas-like fas-associated phosphatase-1 in fas-mediated apoptosis. | recently, one of the pdz domains in the cytosolic protein-tyrosine phosphatase fas-associated phosphatase-1 (fap-1)/protein-tyrosine phosphatase-bas (ptp-bas) was shown to interact with the carboxyl-terminal ts-l-v peptide of the human fas receptor (sato, t., irie, s., kitada, s., and reed, j. c. (1995) science 268, 411-415), suggesting a role for protein (de)phosphorylation in fas signaling. to investigate whether this interaction is conserved in mouse, we performed yeast two-hybrid interaction ... | 1997 | 9374505 |
| protein phosphatase 2c dephosphorylates and inactivates cystic fibrosis transmembrane conductance regulator. | camp-dependent phosphorylation activates the cystic fibrosis transmembrane conductance regulator (cftr) in epithelia. however, the protein phosphatase (pp) that dephosphorylates and inactivates cftr in airway and intestinal epithelia, two major sites of disease, is not certain. we found that in airway and colonic epithelia, neither okadaic acid nor fk506 prevented inactivation of cftr when camp was removed. these results suggested that a phosphatase distinct from pp1, pp2a, and pp2b was responsi ... | 1997 | 9380758 |
| characterization of an adp-ribosylation factor-like 1 protein in saccharomyces cerevisiae. | adp-ribosylation factors (arfs) are highly conserved approximately 20-kda guanine nucleotide-binding proteins that enhance the adp-ribosyltransferase activity of cholera toxin and are believed to participate in vesicular transport in both exocytic and endocytic pathways. several arf-like proteins (arls) have been cloned from drosophila, rat, and human; however, the biological functions of arls are unknown. we have identified a yeast gene (arl1) encoding a protein that is structurally related (>6 ... | 1997 | 9388248 |
| expression and function of a proapoptotic bcl-2 family member bcl-xl/bcl-2-associated death promoter (bad) in rat ovary. | bcl-2-related anti- and proapoptotic proteins are important in the decision step of the intracellular death program upstream from the caspase proteases. targeted overexpression of bcl-2 in ovarian somatic cells of transgenic mice leads to decreased apoptosis of granulosa cells and is associated with higher ovulation rate, increased litter size, and ovarian teratoma formation. the ability of exogenous bcl-2 proteins to promote follicle cell survival suggests that the transgene can bind to endogen ... | 1997 | 9389536 |
| hsp110 protects heat-denatured proteins and confers cellular thermoresistance. | the 110-kda heat shock protein (hsp110) has long been recognized as one of the primary heat shock proteins in mammalian cells. it belongs to a recently described protein family that is a significantly diverged subgroup of the hsp70 family and has been found in organisms as diverse as yeast and mammals. we describe here the first analysis of the ability of hsp110 to protect cellular and molecular targets from heat damage. it was observed that the overexpression in vivo of hsp110 conferred substan ... | 1997 | 9395504 |
| evidence for covalent modification of the nuclear dot-associated proteins pml and sp100 by pic1/sumo-1. | pml and sp100 proteins are associated with nuclear domains, known as nuclear dots (nds). they were discovered in the context of leukemic transformation and as an autoantigen in primary biliary cirrhosis, respectively. both proteins are expressed in the form of many cooh-terminally spliced variants, and their expression is enhanced by interferons (ifn). the recent finding that pic1/sumo-1, a small ubiquitin-like protein, is covalently linked to the rangap1 protein of the nuclear pore complex and ... | 1997 | 9412458 |
| involvement of rabphilin3 in endocytosis through interaction with rabaptin5. | rabphilin3 and rabaptin5 are downstream target molecules of the rab3 and -5 subfamily small g proteins that are implicated in exocytosis and endocytosis, respectively. we examined here the physical and functional relationship between the rab3-rabphilin3 and rab5-rabaptin5 systems. rabphilin3 interacted with rabaptin5 at the n-terminal region (amino acids 1-280), which gtp-rab3a interacted with. the interaction of rabphilin3 with rabaptin5 was inhibited by guanosine 5'-(3-o-thio)triphosphate-rab3 ... | 1998 | 9417123 |
| affinity purification of mammalian rna polymerase i. identification of an associated kinase. | overlapping cdna clones encoding the two largest subunits of rat rna polymerase i, designated a194 and a127, were isolated from a reuber hepatoma cdna library. analyses of the deduced amino acid sequences revealed that a194 and a127 are the homologues of yeast a190 and a135 and have homology to the beta' and beta subunits of escherichia coli rna polymerase i. antibodies raised against the recombinant a194 and a127 proteins recognized single proteins of approximately 190 and 120 kda on western bl ... | 1998 | 9422795 |
| structural and functional properties of the n transcriptional activation domain of thyroid transcription factor-1: similarities with the acidic activation domains. | the thyroid transcription factor 1 (ttf-1) is a tissue-specific transcription factor involved in the development of thyroid and lung. ttf-1 contains two transcriptional activation domains (n and c domain). the primary amino acid sequence of the n domain does not show any typical characteristic of known transcriptional activation domains. in aqueous solution the n domain exists in a random-coil conformation. the increase of the milieu hydrophobicity, by the addition of trifluoroethanol, induces a ... | 1998 | 9425125 |
| co-expression of the proprotein-processing endoprotease furin and its substrate transforming growth factor beta1 and the differentiation of rat hepatocytes. | furin, a member of the yeast kex2 endoprotease family, converts a number of proproteins to their active forms. the liver produces a number of proproteins having a furin-cleavable site; thus, furin may be involved in growth and differentiation both in the partially hepatectomized liver and in primary cultured hepatocytes. furin mrna levels are elevated in tissues regenerated from partially hepatectomized rat liver. in primary culture of rat hepatocytes, furin expression increases gradually with t ... | 1997 | 9426209 |
| differential expression of isoforms of psd-95 binding protein (gkap/sapap1) during rat brain development. | psd-95/sap90, which binds to the c-terminus of nmda receptor and shaker-type potassium channel, is one of the major postsynaptic density proteins. recently, novel classes of proteins interacting with the guanylate kinase domain of psd-95 have been identified, guanylate kinase-associated protein (gkap) and sap90/psd-95-associated proteins (sapaps). here we report the isolation of new isoforms of psd-95 binding protein (gkap/sapap1) using the yeast two-hybrid system. the isolated protein directly ... | 1997 | 9428732 |
| cloning, differential regulation and tissue distribution of alternatively spliced isoforms of adp-ribosylation-factor-dependent phospholipase d from rat liver. | an alternatively spliced isoform of adp-ribosylation-factor-dependent phospholipase d (pld1) was previously shown to occur in rat c6 cells [yoshimura, nakashima, ohguchi, sakai, shinoda, sakai and nozawa (1996) biochem. biophys. res. commun. 225, 494-499] and human hela cells [hammond, jenco, nakashima, cadwallader, gu, cook, nozawa, prestwich, frohman and morris (1997) j. biol. chem. 272, 3860-3868]. however, its complete sequence and the enzymological difference between the two pld1 isoforms w ... | 1998 | 9445394 |
| isozyme function of n-alkane-inducible cytochromes p450 in candida maltosa revealed by sequential gene disruption. | an n-alkane-assimilating yeast candida maltosa contains multiple n-alkane-inducible forms of cytochromes p450 (p450alk), which can be assumed to catalyze terminal hydroxylation of n-alkanes in the assimilation pathway. eight structurally related p450alk genes have been identified. in the present study, the function of four major isoforms of p450alk (encoded by alk1, alk2, alk3, and alk5 genes) was investigated by sequential gene disruption. auxotrophic markers used for the selection of disrupted ... | 1998 | 9461581 |
| further studies on the coupling of mitochondrially bound hexokinase to intramitochondrially compartmented atp, generated by oxidative phosphorylation. | hexokinase, bound to nonphosphorylating rat brain mitochondria, exhibits michaelis-menten kinetic behavior, with an apparent k(m) for atp of 0.44 +/- 0.08 mm. after initiation of oxidative phosphorylation, a steady-state rate of glc phosphorylation is maintained despite the fact that extramitochondrial [atp] continues to increase but remains well below saturating levels (i.e., < 0.4 mm). this independence from extramitochondrial [atp] is taken to indicate that hexokinase is not utilizing extrami ... | 1998 | 9466827 |
| rodent y chromosome tspy gene is functional in rat and non-functional in mouse. | recombination is believed to prevent genetic deterioration in sexual populations because it allows conservation of functional genotypes by removing deleterious mutations. moreover, evidence that non-recombining segments of a genome deteriorate is provided by genetic experiments in drosophila and yeast. y chromosomes generally do not recombine along most of their length, and thus y chromosome genes, despite having been selectively maintained for their function, could be lost from the genome. here ... | 1998 | 9467017 |
| dissection of the translocation and chaperoning functions of yeast bip/kar2p in vivo. | we used the rat nerve growth factor receptor ectodomain (ngfre) and escherichia coli ss-lactamase to dissect the functions of saccharomyces cerevisiae bip/kar2p in vivo. both were fused to the hsp150delta-polypeptide, which promotes proper folding of heterologous proteins which otherwise are misfolded in the yeast er. hsp150delta-ngfre and hsp150delta-beta-lactamase acquired disulfides and were properly folded and oncreted to the culture medium. when disulfide formation was prevented by incubati ... | 1998 | 9472003 |
| the box h + aca snornas carry cbf5p, the putative rrna pseudouridine synthase. | many or all of the sites of pseudouridine (psi) formation in eukaryotic rrna are selected by site-specific base-pairing with members of the box h + aca class of small nucleolar rnas (snornas). database searches previously identified strong homology between the rat nucleolar protein nap57p, its yeast homolog cbf5p, and the escherichia coli psi synthase trub/p35. we therefore tested whether cbf5p is required for synthesis of psi in the yeast rrna. after genetic depletion of cbf5p, formation of psi ... | 1998 | 9472021 |
| neurofilament (nf) assembly; divergent characteristics of human and rodent nf-l subunits. | previous studies have shown that rodent neurofilaments (nf) are obligate heteropolymers requiring nf-l plus either nf-m or nf-h for filament formation. we have assessed the competence of human nf-l and nf-m to assemble and find that unlike rat nf-l, human nf-l is capable of self-assembly. however, human nf-m cannot form homopolymers and requires the presence of nf-l for incorporation into filaments. to investigate the stage at which filament formation is blocked, the rod domains or the full-leng ... | 1998 | 9478962 |
| functional comparison of the yeast scerv1 and scerv2 genes. | the yeast scerv1 gene is the first representative of a new emerging gene family. its gene product is essential for the yeast cell and is involved in the biogenesis of mitochondria and the regulation of the cell cycle. recently the general importance of the gene for the eukaryotic cell was shown by the identification of a structural and functional human homologue. the homologous mammalian alr (augmenter of liver regeneration) genes from man, mouse and rat are important for different developmental ... | 1998 | 9483805 |
| identification and characterization of an endo/exonuclease in pneumocystis carinii that is inhibited by dicationic diarylfurans with efficacy against pneumocystis pneumonia. | dicationic diarylfurans and dicationic carbazoles are under development as therapeutic agents against opportunistic infections. while their ability to bind to the minor groove of dna has been established, the complete mechanism of action has not. we demonstrate here that an effective diarylfuran, 2,5-bis[4-(n-isopropylguanyl)phenyl]furan, inhibits an endo/exonuclease activity present in pneumocystis carinii, cryptococcus neoformans, candida albicans, and saccharomyces cerevisiae. this activity w ... | 1998 | 9495040 |
| heterologous expression and purification of recombinant rolipram-sensitive cyclic amp-specific phosphodiesterases. | with the cloning of cdnas coding for the different phosphodiesterase 4 (pde4) isoenzymes present in mammals, homogeneous preparations of these forms have become readily available. this strategy has greatly facilitated the understanding of the properties of the myriad of isoforms derived from the four pde4 genes found in mammals, and has opened a new avenue to develop inhibitors with a different degree of selectivity for each isoform. here we describe the strategies and methods used to express pd ... | 1998 | 9500858 |
| effects of dietary selenium and vitamin e concentrations on phospholipid hydroperoxide glutathione peroxidase expression in reproductive tissues of pubertal maturing male rats. | phospholipid hydroperoxide glutathione peroxidase (phgpx) is the second intracellular selenium (se)-dependent glutathione peroxidase (gsh-px) identified in mammals. our objectives were to determine the effect of dietary vitamin e and se levels on phgpx activity expression in testis, epididymis, and seminal vesicles of pubertal maturing rats, and the relationship of phgpx expression with testicular development and sperm quality. forty sprague-dawley male weanling rats (21-d old), were initially f ... | 1997 | 9522062 |
| cloning of human p55 gamma, a regulatory subunit of phosphatidylinositol 3-kinase, by a yeast two-hybrid library screen with the insulin-like growth factor-i receptor. | we have used the yeast two-hybrid system to identify proteins that interact with the intracellular domain of the insulin-like growth factor-i receptor (igfir). in a search of a human fetal brain library we identified a cdna encoding a protein that is the human homologue of mouse p55pik, a regulatory subunit of phosphatidylinositol 3-kinase (hp55 gamma). the hp55 gamma protein interacts strongly with the activated igfir but not with the kinase-negative mutant receptor. hp55 gamma also interacts w ... | 1998 | 9524259 |
| the carboxy-terminal domain of hsc70 provides binding sites for a distinct set of chaperone cofactors. | the modulation of the chaperone activity of the heat shock cognate hsc70 protein in mammalian cells involves cooperation with chaperone cofactors, such as hsp40; bag-1; the hsc70-interacting protein, hip; and the hsc70-hsp90-organizing protein, hop. by employing the yeast two-hybrid system and in vitro interaction assays, we have provided insight into the structural basis that underlies hsc70's cooperation with different cofactors. the carboxy-terminal domain of hsc70, previously shown to form a ... | 1998 | 9528774 |
| composition and nutritive value of yeast biomass and yeast protein concentrates. | yeast biomass (saccharomyces sp.) produced in local breweries as a by-product was utilized in this study. percent proximate composition, amino acid composition, and protein nutritive value were determined for the yeast cell biomass (yc), a sodium perchlorate extracted and isoelectrically precipitated protein concentrate (p-pc), and a sodium trimetaphosphate treated extract followed by isoelectrical precipitation (tmp-pc). protein concentrates averaged 75% protein as compared to 48.5% in the yeas ... | 1997 | 9530613 |