Publications

TitleAbstractYear(sorted ascending)
Filter
PMID
Filter
ca2+ transport in saccharomyces cerevisiae.cytosolic free ca2+ is maintained at submicromolar levels in budding yeast by the activity of ca2+ pumps and antiporters. we have recently identified the structural genes for two ca2+ pumps, pmc1 [correction of pcm1] and pmr1, which are required for ca2+ sequestration into the vacuole and secretory organelles, respectively. the function of either ca2+ pump is sufficient for yeast viability, but deletion of both genes is lethal because of elevation of cytosolic [ca2+] and activation of calcineuri ...19947823019
tamoxifen and estrogens as membrane antioxidants: comparison with cholesterol. 19947808336
purification of phosphatidylinositol transfer protein from brain cytosol for reconstituting g-protein-regulated phosphoinositide-specific phospholipase c-beta isozymes. 19947799783
high-level expression of human lipocortin i in the fission yeast schizosaccharomyces pombe using a novel expression vector.we have developed a novel expression system that allows the fission yeast, schizosaccharomyces pombe, to be used for the efficient overproduction of heterologous proteins. as an example of the utility of this system, human lipocortin i was expressed to 50 percent of soluble protein, and 150 mg of highly purified material was obtained from 10 grams of wet cell paste. expression of lipocortin i was driven by the human cytomegalovirus (hcmv) promoter in a vector that also contains a neomycin resist ...19947764687
immunogenicity of polysaccharides conjugated to peptides containing t- and b-cell epitopes.to develop a general model of polysaccharide-peptide vaccine, we have investigated the efficiency of linear peptides derived from protein sr, and adhesin of the i/ii protein antigen family of oral streptococci, to act as carriers for two t cell-independent polysaccharides: serogroup f polysaccharide from streptococcus mutans omz 175 (poly f) and saccharomyces cerevisiae mannan. peptide 3 (yekeptpptrtpdq) and peptide 6 (tpedptdptdpqdpss), accessible on the native sr protein as demonstrated by the ...19947509317
gapiii, a new brain-enriched member of the gtpase-activating protein family.ras gtpase-activating proteins (gaps) are negative regulators of ras, which controls proliferation and differentiation in many cells. ras gaps have been found in a variety of species from yeast to mammals. we describe here a newly identified mammalian gap, gapiii, which was obtained by differential screening of a rat oligodendrocyte cdna library. gapiii putatively encodes a 834 amino acid protein with a predicted molecular weight of 96 kda, which contains a consensus gap-related domain (grd). th ...19957500386
a role for phosphatidylinositol transfer protein in secretory vesicle formation.vesicular traffic in eukaryotic cells is characterized by two steps of membrane rearrangement: the formation of vesicles from donor membranes and their fusion with acceptor membranes. with respect to vesicle formation, several of the cytosolic proteins implicated in budding and fission have been identified. a feature common to all these proteins is that their targets, when known, are other proteins rather than lipids. here we report, using a previously established cell-free system derived from a ...19957566155
effects of solutes on optical properties of biological materials: models, cells, and tissues.perturbations of scattering background for absorbance measurements by photon diffusion techniques complicate algorithms used for determining the concentration of blood and the saturation of hemoglobin in tissues. in order to better define these perturbations, we have undertaken a study of the effect of solutes, some of physiological importance, upon the scattering of three types of model systems: a lipid vessel suspension (intralipid), a cell suspension (baker's yeast), and a tissue (perfused li ...19957573957
an abundant, trans-spliced mrna from toxocara canis infective larvae encodes a 26-kda protein with homology to phosphatidylethanolamine-binding proteins.a full-length mrna encoding a secreted 26-kda antigen of infective larvae of the ascarid nematode parasite toxocara canis has been identified. this was characterized as a 1,082-base pair clone highly abundant (0.8-1.9%) in cdna prepared from infective stage larvae but absent from cdna from adult male worms. sequence analysis revealed an open reading frame corresponding to a hydrophilic 263-amino acid residue polypeptide with a 20-residue n-terminal signal peptide, indicating that it is secreted. ...19957629180
kif2 is a new microtubule-based anterograde motor that transports membranous organelles distinct from those carried by kinesin heavy chain or kif3a/b.kinesin is known as a representative cytoskeletal motor protein that is engaged in cell division and axonal transport. in addition to the mutant assay, recent advances using the pcr cloning technique have elucidated the existence of many kinds of kinesin-related proteins in yeast, drosophila, and mice. we previously cloned five different members of kinesin superfamily proteins (kifs) in mouse brain (aizawa, h., y. sekine, r. takemura, z. zhang, m. nangaku, and n. hirokawa. 1992. j. cell biol. 11 ...19957535303
a provisional transcript map of the spinal muscular atrophy (sma) critical region.yacs from the region containing the spinal muscular atrophy (sma) locus at 5q12 have been used as probes in a direct screening of cdna libraries to isolate 8 cdnas, mapped to different yac fragments. three clones showed complete identity to the genes for cyclin b1 (ccnb1), the p44 subunit of the transcription factor btf2 (btf2p44), and cofilin (cfl). two clones showed partial identity to the beta-glucuronidase gene (glcb) and a rat integral membrane glycoprotein gene (rninmegla). cfl turned out ...19957552146
inhibition of neutral cholesteryl ester hydrolase by the glycolytic enzyme enolase. is this a secondary function of enolase?there is an accumulation of the glycolytic enzyme enolase and of cholesteryl esters in macrophages that have been converted into "foam" cells. in this study, we questioned whether enolase could be involved in this accumulation of cholesteryl esters by inhibiting the activity of neutral cholesteryl ester hydrolases. enolase from both yeast and rabbit muscle were incubated with three different cholesteryl ester hydrolases and were shown to inhibit the hydrolysis of cholesteryl esters. inhibition w ...19957475993
sequential coupling between copii and copi vesicle coats in endoplasmic reticulum to golgi transport.copi and copii are vesicle coat complexes whose assembly is regulated by the arf1 and sar1 gtpases, respectively. we show that copi and copii coat complexes are recruited separately and independently to er (copii), pre-golgi (copi, copii), and golgi (copi) membranes of mammalian cells. to address their individual roles in er to golgi transport, we used stage specific in vitro transport assays to synchronize movement of cargo to and from pre-golgi intermediates, and gdp- and gtp-restricted forms ...19957490291
role of acidic residues in the interaction of nadph-cytochrome p450 oxidoreductase with cytochrome p450 and cytochrome c.site-directed mutagenesis of the acidic clusters 207asp-asp-asp209 and 213glu-glu-asp215 of nadph-cytochrome p450 oxidoreductase demonstrates that both cytochrome c and cytochrome p450 interact with this region; however, the sites and mechanisms of interaction of the two substrates are clearly distinct. substitutions in the first acidic cluster did not affect cytochrome c or ferricyanide reductase activity, but substitution of asparagine for aspartate at position 208 reduced cytochrome p450-depe ...19957499204
cloning and functional analysis of the ndk1 gene encoding nucleoside-diphosphate kinase in schizosaccharomyces pombe.we cloned the ndk1 gene encoding a subunit of nucleoside-diphosphate kinase (ndk) from schizosaccharomyces pombe, by using polymerase chain reaction. the deduced ndk1 gene product has 151 amino acid residues and is approximately 60% identical with both saccharomyces cerevisiae and mammalian ndks. the gene product exhibited ndk activity and cross-reacted with antibodies raised against rat ndk. disruption of ndk1 greatly reduced the cellular ndk activity but caused no obvious phenotype in cell gro ...19957499258
cloning of the cdna for the human atp synthase oscp subunit (atp5o) by exon trapping and mapping to chromosome 21q22.1-q22.2.exon trapping was used to clone portions of potential genes from human chromosome 21. one trapped sequence showed striking homology with the bovine and rat atp synthase oscp (oligomycin sensitivity conferring protein) subunit. we subsequently cloned the full-length human atp synthase oscp cdna (gdb/hgmw approved name atp50) from infant brain and muscle libraries and determined its nucleotide and deduced amino acid sequence (embl/genbank accession no. x83218). the encoded polypeptide contains 213 ...19957490082
positional cloning of the nude locus: genetic, physical, and transcription maps of the region and mutations in the mouse and rat.mutations in the nude locus in mice and rats produce the pleiotropic phenotype of hairlessness and athymia, resulting in severely compromised immune system. to identify the causative gene, we utilized modern tools and techniques of positional cloning. specifically, spanning the region in which the nude locus resides, we constructed a genetic map of polymorphic markers, a physical map of yeast artificial chromosomes and bacteriophage p1 clones, and a transcription map of genes obtained by direct ...19957490093
the usage of oligopeptides in proteins correlates negatively with molecular weight.we scanned the swissprot databank to study the distribution of oligopeptides in sequenced proteins. we observed that in 7839,000 amino acids in the bank, the frequency is strongly and negatively correlated with molecular weight. the correlation coefficient is -0.63 for single amino acids, -0.58 for dipeptides, -0.54 for tri- and -0.46 for tetrapeptides. in subsets of proteins of man, mouse, rat drosophila, yeast and e. coli, the correlations were very similar to those for the total database. the ...19957601605
cloning of a novel family of mammalian gtp-binding proteins (raga, ragbs, ragb1) with remote similarity to the ras-related gtpases.cdna clones of two novel ras-related gtp-binding proteins (raga and ragb) were isolated from rat and human cdna libraries. their deduced amino acid sequences comprise four of the six known conserved gtp-binding motifs (pm1, -2, -3, g1), the remaining two (g2, g3) being strikingly different from those of the ras family, and an unusually large c-terminal domain (100 amino acids) presumably unrelated to gtp binding. raga and ragb differ by seven conservative amino acid substitutions (98% identity), ...19957499430
mitochondrial respiration scavenges extramitochondrial superoxide anion via a nonenzymatic mechanism.we determined that mitochondrial respiration reduced cytosolic oxidant stress in vivo and scavenged extramitochondrial superoxide anion (o2-.) in vitro. first, saccharomyces cerevisiae deficient in both the cytosolic antioxidant cupro-zinc superoxide dismutase (cu,zn-sod) and electron transport (rho0 state) grew poorly (p < 0.05) in 21% o2 compared with parent yeast and yeast deficient only in electron transport or cu,zn-sod, whereas anaerobic growth was the same (p > 0.05) in all yeast. second, ...19957635949
molecular cloning of the human gene encoding lanosterol synthase from a liver cdna library.lanosterol synthase [(s)-2,3-epoxysqualene mutase (cyclizing, lanosterol forming), ec 5.4.99.7] catalyzes the cyclization of (s)-2,3-oxidosqualene to lanosterol in the reaction that forms the sterol nucleus. we report herein the cloning and characterization of the human gene (osc) encoding lanosterol synthase, a predicted 83 kda protein of 732 amino acids. the deduced amino acid sequence is 36-40% identical to known yeast and plant homologues and 83% identical to rattus norvegicus lanosterol syn ...19957639730
solubilization and identification of essential functional groups of candida albicans oxidosqualene cyclase.the enzyme properties and location of essential functional groups of solubilized oxidosqualene cyclase of candida albicans have been studied. we show that the c. albicans enzyme is much more heat-labile compared with saccharomyces cerevisiae and rat liver cyclases, requires a histidyl residue for enzyme activity, contains an essential thiol residue either close to or in the active site and exhibits a carbocationic mechanism for catalysis, as the enzyme-bound substrate protects the enzyme from in ...19957650579
amino acid sequence of the ribosomal protein hs23 from the halophilic haloarcula marismortui and homology studies to other ribosomal proteins.the ribosomal protein hs23 from the 30s subunit of the extreme halophilic haloarcula marismortui, belonging to the group of archaea, was isolated either by rp-hlplc or two-dimensional polyacrylamide gel electrophoresis. the complete amino acid sequence was determined by automated n-terminal microsequencing. the protein consists of 123 residues with a corresponding molecular mass of 12,552 da as determined by electrospray mass spectroscopy; the pi is 11.04. homology studies reveal similarities to ...19957662106
2,3-oxidosqualene cyclase: from azasqualenes to new site-directed inhibitors.2,3-oxidosqualene cyclases (osc) are enzymes which convert 2,3-oxidosqualene (os) into polycyclic triterpenoids such as lanosterol, cycloartenol, and alpha- and beta-amyrin. our interest in the study of osc is the development of new osc inhibitors for potential use as hypocholesterolemic, antifungal, or phytotoxic drugs. in particular, we describe the biological activity and the mechanism of a series of acyclic azasqualene derivatives mimicking the c-2, c-8, and c-20 carbonium ions formed during ...19957791532
n-oxygenation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine by the rat liver flavin-containing monooxygenase expressed in yeast cells.n-oxygenation of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (mptp), a dopaminergic neurotoxin, was studied using recombinant rat liver flavin-containing monooxygenase (fmo), fmo1a1, expressed in yeast cells. the mean (+/- s.d.) kinetic parameters of mptp n-oxygenation were: km = 1.8 +/- 0.5 microm, vmax = 9.5 +/- 1.6 nmol/mg per min, and vmax/km = 4.6 +/- 0.5 ml/mg per min. n-octylamine, an activator of fmo, enhanced the mptp n-oxygenation activity by 51%, while methimazole, thiobenzamide and ...19957672012
the oncogene qin codes for a transcriptional repressor.the retroviral oncogene qin codes for a protein that belongs to the winged helix family of transcriptional regulators. the qin protein is localized in the nucleus and binds to the same dna consensus sequence as rat brain factor 1 (bf-1). cellular qin shows greater affinity to dna than does viral qin. alone or fused to the dna-binding domain of the yeast gal4 protein, both qin proteins act as transcriptional repressors. the major transcriptional repression domain maps to the region of amino acids ...19957585630
expression in escherichia coli, purification and functional activity of recombinant human chaperonin 10.we have recently reported the cloning of a cdna coding for a stress inducible human chaperonin 10. the protein was shown to possess 100% identity with the bovine homologue and a single amino acid replacement (glycine to serine at position 52) compared to rat chaperonin 10. here we report the heterologous expression of human chaperonin 10 in escherichia coli, its purification and its functional characterization. the recombinant protein was purified to homogeneity as judged by different analytical ...19957698325
cloning and expression of human deoxyhypusine synthase cdna. structure-function studies with the recombinant enzyme and mutant proteins.deoxyhypusine synthase catalyzes the first step in the post-translational formation of hypusine (n epsilon-(4-amino-2-hydroxybutyl)lysine). cdna clones encoding deoxyhypusine synthase were isolated from a human hela cell library. full-length cdna clones encoding a 369-amino acid protein (calculated molecular mass of 40,970 da) and a shorter cdna clone that would potentially encode a protein with an internal deletion of 56 amino acids (asp262-ser317) were isolated. the deduced amino acid sequence ...19957673224
secretion of biologically active recombinant fibrinogen by yeast.fibrinogen (340 kda) is a plasma protein that plays an important role in the final stages of blood clotting. human fibrinogen is a dimer with each half-molecule composed of three different polypeptides (a alpha, 67 kda; b beta, 57 kda; gamma, 47 kda). to understand the mechanism of fibrinogen chain assembly and secretion and to obtain a system capable of producing substantial amounts of fibrinogen for structure-function studies, we developed a recombinant system capable of secreting fibrinogen. ...19957559549
yeast synaptobrevin homologs are modified posttranslationally by the addition of palmitate.yeast possess two homologs of the synaptobrevin family of vesicle-associated membrane proteins that function in membrane recognition and vesicle fusion. yeast proteins snc1 and snc2 localize to secretory vesicles and are required for constitutive exocytosis. they also form a physical complex with a plasma membrane protein, sec9, which is necessary for vesicle docking and fusion to occur in vivo. formation of this molecular complex, as a prerequisite for vesicle fusion, appears to have been conse ...19957597066
class iii alcohol dehydrogenase from saccharomyces cerevisiae: structural and enzymatic features differ toward the human/mammalian forms in a manner consistent with functional needs in formaldehyde detoxication.alcohol dehydrogenase class iii (glutathione-dependent formaldehyde dehydrogenase) from saccharomyces cerevisiae was purified and analyzed structurally and enzymatically. the corresponding gene was also analyzed after cloning from a yeast genome library by screening with a probe prepared through pcr amplification. as with class iii alcohol dehydrogenase from other sources, the yeast protein was obtained in two active forms, deduced to reflect different adducts/modifications. protein analysis est ...19957649298
phosphorylation of tau protein by casein kinase-1 converts it to an abnormal alzheimer-like state.the microtubule-associated protein tau is abnormally hyperphosphorylated in alzheimer's disease. both proline-dependent protein kinases (pdpks) and non-pdpks are involved in this hyperphosphorylation of tau. several pdpks can phosphorylate tau in vitro and induce alzheimer-like epitopes to many phosphorylation-dependent antibodies. a similar induction has not been reported with non-pdpks. in this study we have evaluated six non-pdpks [cyclic amp-dependent (a-kinase), calcium/phospholipid-depende ...19957532213
cloning and functional expression of the cdna encoding rat lanosterol 14-alpha demethylase.lanosterol 14 alpha-demethylase (ldm) is a cytochrome p-450 enzyme in the biosynthetic pathway of cholesterol. as such, it represents a target for cholesterol-lowering drugs. rat ldm (rldm) has been purified from the livers of rats treated with cholestyramine. the purified protein was used to generate tryptic fragments which were then sequenced. the amino acid (aa) sequences were used to design oligodeoxyribonucleotide primers and a dna fragment was generated by rt-pcr to probe a phagemid librar ...19957665087
peroxisome structure, function, and biogenesis--human patients and yeast mutants show strikingly similar defects in peroxisome biogenesis.peroxisomes are found in almost all eukaryotic cells. two major functions of the organelle are in lipid metabolism: peroxisomes catalyze the initial steps in the biosynthesis of plasmalogens, which are phospholipids that are present in large amounts in myelin. peroxisomes also catalyze the beta-oxidation of fatty acids; this pathway is essential for the catabolism of a variety of substrates that are not oxidized by mitochondria. a third important function is in cellular respiration, involving th ...19957666062
interaction cloning of rabin3, a novel protein that associates with the ras-like gtpase rab3a.rab3a is a small, ras-like gtpase expressed in neuroendocrine cells, in which it is associated with secretory vesicle membranes and regulates exocytosis. using the yeast two-hybrid system, we have identified a rat brain cdna encoding a novel 50-kda protein, which we have named rabin3, that interacts with rab3a and rab3d but not with other small gtpases (rab3c, rab2, ran, or ras). several independent point mutations in the effector domain of rab3a (f51l, v55e, and g56d) which do not alter nucleot ...19957532276
identification of heterogeneous ribonucleoprotein a1 as a novel substrate for protein kinase c zeta.the zeta isoform of protein kinase c (zeta pkc) has been shown to be an important step in mitogenic signal transduction. using a yeast interaction screen to search for potential novel substrates of zeta pkc, we identified the heterogeneous ribonucleoprotein a1 (hnrnpa1). this protein specifically interacts with the catalytic domain of zeta pkc but not with its regulatory region or with the full-length protein, or with a kinase-defective mutant of the zeta pkc catalytic domain. in addition, no in ...19957541049
cloning and nucleotide sequence of a specific dna fragment from paracoccidioides brasiliensis.we cloned and sequenced a species-specific 110-bp dna fragment from paracoccidioides brasiliensis. the dna fragment was generated by pcr with primers complementary to the rat beta-actin gene under a low annealing temperature. comparison of the nucleotide sequence, after excluding the primers, with those in the genbank database identified approximately 60% homology with an exon of a major surface glycoprotein gene from pneumocystis carinii and a fragment of unknown function in saccharomyces cerev ...19957650207
evidence that epithelial glycoprotein 330/megalin mediates uptake of polybasic drugs.glycoprotein 330 (gp330) is an endocytic receptor expressed in the renal proximal tubules and some other absorptive epithelia, e.g., in the inner ear. the present study shows that the antifibrinolytic polypeptide, aprotinin, and the nephro- and ototoxic antibiotics, aminoglycosides, and polymyxin b compete for binding of 125i-urokinase-plasminogen activator inhibitor type-1 complexes to purified rabbit gp330. half maximal inhibition was measured at 4 microm for aprotinin, 50 microm for gentamici ...19957544804
assembly of voltage-gated potassium channels. conserved hydrophilic motifs determine subfamily-specific interactions between the alpha-subunits.voltage-gated potassium (k+) channels are assembled by four identical or homologous alpha-subunits to form a tetrameric complex with a central conduction pore for potassium ions. most of the cloned genes for the alpha-subunits are classified into four subfamilies: kv1 (shaker), kv2 (shab), kv3 (shaw), and kv4 (shal). subfamily-specific assembly of heteromeric k+ channel complexes has been observed in vitro and in vivo, which contributes to the diversity of k+ currents. however, the molecular cod ...19957559593
characterization of the progesterone 21-hydroxylase activity of canine cytochrome p450 pbd-2/p450 2b11 through reconstitution, heterologous expression, and site-directed mutagenesis.canine hepatic cytochrome p450 pbd-2 metabolizes 2,2',4,4',5,5'-hexachlorobiphenyl and catalyzes the 21-hydroxylation of progesterone, thereby distinguishing pbd-2 as unique among 2b p450s. heterologous expression of the pbd-2 cdna, p450 2b11, in cos and yeast systems produced a protein capable of androstenedione metabolism; however, this p450 did not metabolize progesterone in a manner consistent with pbd-2. modification of pbd-2 reconstitution parameters resulted in significantly increased cat ...19957587957
liver fructose-1,6-bisphosphatase cdna: trans-complementation of fission yeast and characterization of two human transcripts.the sv40 early promoter is active both in mammalian cells and in the fission yeast schizosaccharomyces pombe, and is used to drive full-length cdna in polyvalent pcd-libraries. two such liver libraries, of human and rat origin, were used to trans-complement a s. pombe mutant deficient in fructose-1,6-bisphosphatase (fru-1,6-pase) activity, a key gluconeogenic enzyme restricted to liver, kidney and intestine in mammals. a rat liver fru-1,6-pase cdna was readily cloned and sequenced. complementary ...19957589895
a proline-rich sequence unique to mek1 and mek2 is required for raf binding and regulates mek function.mammalian mek1 and mek2 contain a proline-rich (pr) sequence that is absent both from the yeast homologs ste7 and byr1 and from a recently cloned activator of the jnk/stress-activated protein kinases, sek1/mkk4. since this pr sequence occurs in meks that are regulated by raf family enzymes but is missing from meks and seks activated independently of raf, we sought to investigate the role of this sequence in mek1 and mek2 regulation and function. deletion of the pr sequence from mek1 blocked the ...19957565670
marked effects of alcohols and imidazoles on the cumyl hydroperoxide reaction with the wild-type cytochrome p450 1a2.cytochrome p450 catalyzes monooxidation reactions of many organic compounds in the presence of hydroperoxides even in the absence of electron-transfer proteins and molecular oxygen. to understand the mechanism of the hydroperoxide-induced cytochrome p450 reactions, we investigated effects of ligands such as alcohols and imidazoles and 7-ethoxycoumarin, a substrate of cytochrome p450 1a2 (p450 1a2), on the cumyl hydroperoxide (chp) o-o cleavage reaction with wild-type p450 1a2. formation rates of ...19957574687
targeting signals and subunit interactions in coated vesicle adaptor complexes.there are two clathrin-coated vesicle adaptor complexes in the cell, one associated with the plasma membrane and one associated with the tgn. the subunit composition of the plasma membrane adaptor complex is alpha-adaptin, beta-adaptin, ap50, and ap17; while that of the tgn adaptor complex is gamma-adaptin, beta'-adaptin, ap47, and ap19. to search for adaptor targeting signals, we have constructed chimeras between alpha-adaptin and gamma-adaptin within their nh2-terminal domains. we have identif ...19957593184
petunia hybrida homologues of shaggy/zeste-white 3 expressed in female and male reproductive organs.petunia hybrida ovule-specific cdna libraries were screened for genes encoding homologues of protein kinases known to be involved in developmental processes. two cdnas, psk4 and psk6 (petunia hybrida shaggy related protein kinase), homologous to gsk-3 from rat, mds1 from yeast and to the segment polarity gene shaggy/zeste-white 3 (sgg/zw3) from drosophila were characterized in detail. southern blot analysis showed that the psk4 and psk6 genes belong to a small multigene family in p. hybrida. the ...19957599650
variable effects of maturity-onset-diabetes-of-youth (mody)-associated glucokinase mutations on substrate interactions and stability of the enzyme.mutations in the human glucokinase (gk) gene are thought to cause maturity-onset diabetes of youth (mody) by leading to the production of enzymes with reduced catalytic activities and increased glucose km values. however, in some cases the diabetic phenotype is more severe than might be predicted from these apparent kinetic effects alone. to determine whether these mutations might also effect other characteristics of the enzyme, nine mody-associated mutants were expressed as fusion proteins with ...19957619052
developmental regulation of the catalytic subunit of the apolipoprotein b mrna editing enzyme (apobec-1) in human small intestine.apolipoprotein (apo) b mrna editing is a site-specific cytidine deamination reaction responsible for the production of apob-48 in mammalian small intestine. this process is mediated by an enzyme complex that includes the catalytic subunit, apobec-1. in the present study, it is shown that the developmental regulation of apob mrna editing in fetal human small intestine is closely mirrored by accumulation of apobec-1 mrna. similar results were obtained using caco-2 cells, the data further suggestin ...19957595088
dissection of transcription factor tfiif functional domains required for initiation and elongation.tfiif is unique among the general transcription factors because of its ability to control the activity of rna polymerase ii at both the initiation and elongation stages of transcription. mammalian tfiif, a heterodimer of approximately 30-kda (rap30) and approximately 70-kda (rap74) subunits, assists tfiib in recruiting rna polymerase ii into the preinitiation complex and activates the overall rate of rna chain elongation by suppressing transient pausing by polymerase at many sites on dna templat ...19957597077
the role of inositol acylation and inositol deacylation in gpi biosynthesis in trypanosoma brucei.the compound diisopropylfluorophosphate (dfp) selectively inhibits an inositol deacylase activity in living trypanosomes that, together with the previously described phenylmethylsulfonyl fluoride (pmsf)-sensitive inositol acyltransferase, maintains a dynamic equilibrium between the glycosylphosphatidylinositol (gpi) anchor precursor, glycolipid a [nh2(ch2)2po4-6man alpha 1-2man alpha 1-6man alpha 1-4glcn alpha 1-6myo-inositol-1-po4-sn-1,2-dimyristoylglycerol], and its inositol acylated form, gly ...19957621823
identification of yhr068w in saccharomyces cerevisiae chromosome viii as a gene for deoxyhypusine synthase. expression and characterization of the enzyme.deoxyhypusine synthase catalyzes the formation of deoxyhypusine, the first step in hypusine biosynthesis. amino acid sequences of five tryptic peptides from rat deoxyhypusine synthase were found to match partially the deduced amino acid sequence of the open reading frame of gene yhr068w of saccharomyces cerevisiae chromosome viii (ac:u00061). in order to determine whether the product of this gene corresponds to yeast deoxyhypusine synthase,a 1.17-kilobase pair cdna with an identical nucleotide s ...19957629166
rbsec1a and b colocalize with syntaxin 1 and snap-25 throughout the axon, but are not in a stable complex with syntaxin.rbsec1 is a mammalian neuronal protein homologous to the yeast sec1 gene product which is required for exocytosis. mutations in sec1 homologues in the nervous systems of c. elegans and d. melanogaster lead to defective neurotransmitter secretion. biochemical studies have shown that recombinant rbsec1 binds syntaxin 1 but not snap-25 or synaptobrevin/vamp, the two proteins which together with syntaxin 1 form the synaptic snare complex. in this study we have examined the subcellular localization o ...19957698978
multiple promoters in rat acyl-coa synthetase gene mediate differential expression of multiple transcripts with 5'-end heterogeneity.nucleotide sequence analysis of six independently isolated cdnas for rat acyl-coa synthetase (acs) revealed three forms of acs mrna, designated form-a, -b, and -c mrnas, which differ in their 5'-untranslated regions. form-a mrna was preferentially detected in normal and peroxisome-induced livers, whereas form-b mrna was found in peroxisome-induced livers but not in normal livers and hearts, and form-c mrna was preferentially found in normal hearts and peroxisome-induced livers. analysis of two o ...19957721900
drosophila udp-glucose:glycoprotein glucosyltransferase: sequence and characterization of an enzyme that distinguishes between denatured and native proteins.a drosophila udp-glucose:glycoprotein glucosyltransferase was isolated, cloned and characterized. its 1548 amino acid sequence begins with a signal peptide, lacks any putative transmembrane domains and terminates in a potential endoplasmic reticulum retrieval signal, hgel. the soluble, 170 kda glycoprotein occurs throughout drosophila embryos, in microsomes of highly secretory drosophila kc cells and in small amounts in cell culture media. the isolated enzyme transfers [14c]glucose from udp-[14c ...19957729408
amino acid sequence of rat kidney glutathione synthetase.glutathione (gsh) synthetase [gamma-l-glutamyl-l-cysteine:glycine ligase (adp-forming), ec 6.3.2.3], an enzyme present in almost all cells, catalyzes the atp-dependent synthesis of gsh from gamma-l-glutamyl-l-cysteine and glycine. highly purified preparations of the enzyme have been obtained from rat kidney and several lower forms. the rat kidney enzyme (m(r), 118,000), which contains approximately 2% carbohydrate, is composed of two apparently identical subunits. the cdna encoding rat kidney gs ...19957862666
inhibitors of pig kidney trehalase.trehazolin, a new trehalase inhibitor isolated from the culture broth of micromonospora, was reported to be a highly specific inhibitor for porcine and silk worm trehalases with ic50 values of 5.5 x 10(-9) and 3.7 x 10(-9) m, respectively (o. ando, h. satake, k. itoi, a. sato, m. nakajima, s. takashi, h. haruyama, y. ohkuma, t. kinoshita, and r. enokita (1991) j. antibiot. 44, 1165-1168). we also found that trehazolin is a very powerful and quite specific inhibitor against purified pig kidney tr ...19957864639
immunotechnological trends in radioimmunotargeting: from 'magic bullet' to 'smart bomb'.the impact of recent advances in the chemical and genetic engineering manipulations of antibodies on radioimmunotargeting is reviewed both in relation to radioimmunoscintigraphy and radioimmunotherapy. the resulting trends are: (1) the linking of parts of the mouse/rat and human antibody molecule; (2) the creation of molecules with dual antigen or multiple antigen recognition capabilities; (3) the making of smaller and smaller antigen recognition molecules; and (4) the development of molecules w ...19957731620
the hepatitis b virus x protein targets the basic region-leucine zipper domain of creb.the x gene product encoded by the hepatitis b virus, termed px, is a promiscuous transactivator of a variety of viral and cellular genes under the control of diverse cis-acting elements. although px does not appear to directly bind dna, px-responsive elements include the nf-kappa b, ap-1, and cre (camp response element) sites. direct protein-protein interactions occur between viral px and the cre-binding transcription factors creb and atf. here we examine the mechanism of the protein-protein int ...19957731990
the peptide repeat domain of nucleoporin nup98 functions as a docking site in transport across the nuclear pore complex.we report the cdna deduced primary structure of a wheat germ agglutinin-reactive nuclear pore complex (npc) protein of rat. the protein, termed nup98 (for nucleoporin of 98 kda), contains numerous glfg and fg repeats and some fxfg repeats and is thus a vertebrate member of a family of glfg nucleoporins that were previously discovered in yeast. immunoelectron microscopy showed nup98 to be asymmetrically located at the nucleoplasmic side of the npc. nup98 functions as one of several docking site n ...19957736573
cloning and identification of arp1, an actin-related protein from pneumocystis carinii.the complete pneumocystis carinii arp1 gene has been sequenced from two cdna clones. the gene encodes a protein 385 bp in length with an estimated size of 45,000 kd. the a + t% for the arp1 gene and a 900-bp sequence upstream of the gene were 63.7% and 70.3%, respectively. these values are consistent with a + t codon preference displayed by p. carinii and are similar to values reported for other p. carinii genes. the predicted amino acid sequence of the p. carinii arp1 protein had a similarity o ...19957757056
kinetic characteristics of rat liver peroxisomal nafenopin-coa ligase.in this study we have demonstrated that rat hepatic peroxisomes catalyse the formation of nafenopin-coa. the process is mediated by apparent high affinity (km 6.7 microm), low capacity (vmax 0.31 nmol/mg/min) and low affinity, high capacity isoforms. palmitic acid (ki 1.1 microm), r(-) ibuprofen (ki 7.9 microm), ciprofibrate (ki 60.2 microm) and clofibric acid (ki 86.8 microm) competitively inhibited nafenopin-coa formation catalysed by the apparent high affinity isoform. an antibody raised agai ...19957763316
identification of a nuclear receptor that is activated by farnesol metabolites.nuclear hormone receptors comprise a superfamily of ligand-modulated transcription factors that mediate the transcriptional activities of steroids, retinoids, and thyroid hormones. a growing number of related proteins have been identified that possess the structural features of hormone receptors, but that lack known ligands. known as orphan receptors, these proteins represent targets for novel signaling molecules. we have isolated a mammalian orphan receptor that forms a heterodimeric complex wi ...19957774010
requirement of tyrosine- and serine/threonine kinases in the transcriptional activation of the mammalian grp78/bip promoter by thapsigargin.depletion of endoplasmic reticulum (er) ca2+ store by thapsigargin (tg) in mammalian cells induces a set of er protein genes known as the glucose-regulated proteins. recently, ire1p, a transmembrane protein postulated to have a serine/threonine kinase activity, has been identified as required for the induction of er resident proteins genes in saccharomyces cerevisiae. to investigate whether ire1p can stimulate mammalian grp transcription, a stable chinese hamster ovary cell line containing ampli ...19957814417
carbethoxylating agents as inhibitors of aldehyde dehydrogenase.n,o-dicarbethoxy-4-chlorobenzenesulfohydroxamate (1c) and o-carbethoxy-n-hydroxysaccharin (6), both potential carbethoxylating agents, inhibited yeast aldehyde dehydrogenase (aldh) with ic50's of 24 and 56 microm, respectively. the esterase activity of the enzyme was commensurably inhibited. aldh activity was only partially restored on incubation with mercaptoethanol (20 mm) for 1 h. on incubation with rat plasma, 1c liberated nitroxyl, a potent inhibitor of aldh. under the same conditions, nitr ...19957783119
evidence from antibody studies that the cag repeat in the huntington disease gene is expressed in the protein.the neurodegenerative disorder huntington disease (hd) appears to be caused by an increase in the number of repeats of the trinucleotide cag located near the 5' end of the gene. the nucleotide sequences of the cdna and the gene predict that the hd protein has a molecular weight of 347,000 (3144 amino acids) and that the cag repeats encode a segment of polyglutamine beginning 17 amino acids from the amino terminus. because the cag repeat plays such a critical role in the etiology of the disease, ...19957795604
affinity-purification and identification of grpe homologues from mammalian mitochondria.we used affinity chromatography on dnak columns to identify a mitochondrial grpe homologue from bovine, porcine and rat liver mitochondria. the 24 kda grpe homologue bound specifically to the dnak column and was not eluted with 1 m kcl but readily with 5 mm atp. sequence analysis of the bovine homologue (85 residues) revealed 42% positional identity to mitochondrial grpep from s. cerevisiae and about 30% identity to the bacterial counterparts. thus, grpe homologues from higher and lower eukaryot ...19957711059
the protooncogene c-jun contains an unusual estrogen-inducible enhancer within the coding sequence.estrogens have previously been shown to induce c-jun mrna levels in target cells during hormone induced proliferation, and this appears to be a primary hormonal response involving transcriptional activation. in this report we have now identified an estrogen dependent enhancer within the coding sequence of c-jun. this element has the sequence gcagannntgacc which is identical to the consensus estrogen response element ggtcannntgacc in the second half site, but varies considerably in the first half ...19957721748
localization of i2-imidazoline binding sites on monoamine oxidases.imidazoline binding sites (ibs) were proposed to be responsible for some of the pharmacological and therapeutic activities of imidazoline and related compounds and have been classified into two subtypes, i1bs and i2bs. convergent studies attribute a role in central blood pressure regulation to the i1bs. in contrast, the function of i2bs remains unknown. in the present study, by combining biochemical and molecular biology approaches, we show that 1) microsequencing of i2bs purified from rabbit ki ...19957730367
distribution of the kexin family proteases in pancreatic islets: pace4c is specifically expressed in b cells of pancreatic islets.the distribution of kexin family proteases in adult rat pancreatic islets was investigated by immunohistochemical means using a series of specific antibodies specific for pc1, pc2, pc6, furin, pace4a and a recently identified member of the kexin family, pace4c. pace4c expression was limited to b cells of the pancreatic islets. pc2 was found in a and in some d cells more than in b cells and pc1 was evident only in b cells. furin and pc6 were weakly and evenly expressed in the entire islet. pace4a ...19957828552
the ligand-binding domains of the thyroid hormone/retinoid receptor gene subfamily function in vivo to mediate heterodimerization, gene silencing, and transactivation.the ligand-binding domains (lbds) of the thyroid/retinoid receptor gene subfamily contain a series of heptad motifs important for dimeric interactions. this subfamily includes thyroid hormone receptors (t3rs), all-trans retinoic acid (ra) receptors (rars), 9-cis ra receptors (rars and retinoid x receptors [rxrs]), the 1,25-dihydroxyvitamin d3 receptor (vdr), and the receptors that modulate the peroxisomal beta-oxidation pathway (ppars). these receptors bind to their dna response elements in vitr ...19957862171
molecular cloning and functional expression in yeast of a human camp-specific phosphodiesterase subtype (pde iv-c).we have recently reported increased survival of dopaminergic substantia nigra neurons by inhibition of phosphodiesterase type iv enzymes. as a first step to unravel the involvement of pde iv subtypes in this process, we isolated phosphodiesterase type iv cdnas from human substantia nigra. one isolated partial cdna clone was most homologous to the partially cloned rat and human pde iv-c isogene. distribution analysis revealed that the enzyme is expressed in various tissues but not in cells of the ...19957843419
mepyramine, a histamine h1 receptor antagonist, inhibits the metabolic activity of rat and human p450 2d forms.the interaction of antihistaminics, including mepyramine, with rat hepatic cytochrome p450s (p450s) was investigated. we first investigated mepyramine binding to eight forms of rat hepatic p450s. mepyramine bound specifically to p450 2d1, which suggests that it inhibits p450 2d activity. histamine h1 receptor antagonists (mepyramine, diphenhydramine, chlorpheniramine and triprolidine) inhibited the lidocaine 3-hydroxylation activity catalyzed by p450 2d1 but did not inhibit the testosterone hydr ...19957853212
genetic dissection of thyroid hormone receptor beta: identification of mutations that separate hormone binding and transcriptional activation.the thyroid hormone receptors (tr) are members of the nuclear receptor family of ligand-mediated transcription factors. the large region of tr that lies c-terminal to its dna-binding domain subserves functions of ligand binding, dimerization, and transactivation. little is known regarding the structural or functional determinants of these processes. we have utilized genetic screening in the yeast saccharomyces cerevisiae to identify residues involved in these functions. random mutations of the r ...19957862143
cloning, expression, and characterization of cdnas encoding arabidopsis thaliana squalene synthase.we have isolated and characterized two overlapping cdna clones for arabidopsis thaliana squalene synthase. their nucleotide sequences contained an open reading frame for a 410-amino acid polypeptide (calculated molecular mass, 47 kda). the deduced amino acid sequence of the arabidopsis polypeptide was significantly homologous (42-44% identical) to the sequences of known squalene synthases of several species, from yeast to man, but it was much less homologous to that of tomato phytoene synthase. ...19957892265
control of de novo purine biosynthesis genes in ureide-producing legumes: induction of glutamine phosphoribosylpyrophosphate amidotransferase gene and characterization of its cdna from soybean and vigna.soybean (glycine max) and mothbean (vigna aconitifolia) cdna clones encoding glutamine phosphoribosylpyrophosphate amidotransferase (prat), the first enzyme of the de novo purine biosynthesis pathway, have been isolated from nodule cdna libraries. the amino acid sequence deduced from soybean clone showed > 85% homology to the prat sequence of mothbean and 33-47% homology to those of bacteria, yeast, chicken, rat and human. the soybean clone encodes a protein with an n-terminal sequence resemblin ...19957894513
a novel ubiquitous form of munc-18 interacts with multiple syntaxins. use of the yeast two-hybrid system to study interactions between proteins involved in membrane traffic.munc-18-1 is a 67-kda neuronal protein that binds tightly to syntaxin 1 and functions in synaptic vesicle exocytosis (hata, y., slaughter, c.a., and südhof, t.c. (1993a) nature 366, 347-351). we have now characterized a new munc-18 isoform, munc-18-2, that exhibits 63% amino acid sequence identity with munc-18-1. munc-18-2 is expressed in most tissues, whereas munc-18-1 is primarily expressed in brain. using recombinant munc-18-1 and munc-18-2 produced in cos cells, we show that both forms of mu ...19957768895
transcription factor genes from rat pneumocystis carinii.genes encoding the tfiid tata-box binding protein (tbp) from two probable species of rat pneumocystis carinii (prototype and variant) were sequenced. the two p. carinii tbp gene sequences were 91% identical to each other, and 65-77% identical to tbp genes from other species. a cdna from one of the two p. carinii tbp genes was sequenced, which showed that four small introns resided in identical positions within the tbp genes from the prototype and variant rat p. carinii. conservation of the 180 a ...19957728137
evaluation of the sa locus in human hypertension.the sa gene is expressed at 10-fold greater levels in the kidney of the spontaneously hypertensive rat compared with the normotensive wistar-kyoto rat. the gene is linked to blood pressure levels in a number of crosses involving the spontaneously hypertensive rat and other strains of genetically hypertensive rats. to assess its role in human hypertension, a human sa cdna was cloned from a liver library. the cdna was 1513 bp in length and exhibited a high identity with the published rat sa cdna s ...19957843754
scaled-up expression of human alpha 2,6(n)sialyltransferase in saccharomyces cerevisiae.expression of recombinant full length human alpha 2,6(n)sialyltransferase has been scaled-up in s. cerevisiae in a 150-l bioreactor yielding 47 u at a concentration of 0.31 u/l. the protein specific activity as measured in reconstituted yeast lyophilisate was 0.8 mu/mg protein. the recombinant enzyme exhibited similar michaelis constants as previously determined for the native rat enzyme. by immunoblotting the enzyme was shown to be heterogeneous by size (44-48 kd) and n-glycosylated. we conclud ...19957741734
molecular cloning and characterization of cdna encoding the alpha subunit of the rat protein synthesis initiation factor eif-2b.eukaryotic initiation factor 2b (eif-2b) is an essential component of the pathway of peptide-chain initiation in mammalian cells, yet little is known about its molecular structure and regulation. to investigate the structure, regulation, and interactions of the individual subunits of eif-2b, we have begun to clone, characterize, and express the corresponding cdnas. we report here the cloning and characterization of a 1510-bp cdna encoding the alpha subunit of eif-2b from a rat brain cdna library ...19957753796
molecular cloning and functional expression of a cdna for mouse squalene synthase.using a probe obtained by pcr amplification, a full-length cdna encoding squalene synthase was isolated from a mouse liver cdna library. its nucleotide sequence had an open reading frame fro a 416 amino acid polypeptide (calculated molecular mass, 48 kda). in vitro transcription of the cdna followed by in vitro translation produced a protein of the expected size. the deduced amino acid sequence was 93%, 88% and 46% identical to those of the rat, human and budding yeast squalene synthases, respec ...19957999794
golgi localization in yeast is mediated by the membrane anchor region of rat liver sialyltransferase.to investigate the function of the membrane anchor region of a mammalian glycosyltransferase in yeast we constructed a fusion gene that encodes the 34 amino-terminal residues of rat liver beta-galactoside alpha-2,6-sialyl-transferase (ec 2.4.99.1) (st) fused to the mature form of yeast invertase. transformants of saccharomyces cerevisiae expressing the fusion gene produced an intracellular heterogeneously n-glycosylated fusion protein of intermediate molecular weight between the core and fully e ...19957890665
recombinant rat cbf-c, the third subunit of cbf/nfy, allows formation of a protein-dna complex with cbf-a and cbf-b and with yeast hap2 and hap3.the ccaat binding factor cbf is a heteromeric transcription factor, which binds to functional ccaat motifs in many eukaryotic promoters. cdnas for the a and b subunits of cbf (cbf-a and cbf-b) and for their yeast homologues hap3 and hap2 have been previously isolated, but the purified recombinant cbf-a and cbf-b together are unable to bind to ccaat motifs in dna. here we report the isolation of a cdna coding for rat cbf-c, demonstrate that recombinant cbf-c is required together with cbf-a and cb ...19957878029
cloning and functional characterization of a mammalian zinc transporter that confers resistance to zinc.a cdna encoding a zinc transporter (znt-1) was isolated from a rat kidney cdna expression library by complementation of a mutated, zinc-sensitive bhk cell line. this cdna was used to isolate the homologous mouse znt-1 gene. the proteins predicted for these transporters contain six membrane-spanning domains, a large intracellular loop and a c-terminal tail. znt-1 is homologous to zinc and cobalt resistance genes of yeast. immunocytochemistry with an antibody to a myc epitope added to the c-termin ...19957882967
human alpha-tocopherol transfer protein: cdna cloning, expression and chromosomal localization.alpha-tocopherol transfer protein (alpha ttp), which specifically binds this vitamin and enhances its transfer between separate membranes, was previously isolated from rat liver cytosol. in the current study we demonstrated the presence of alpha ttp in human liver by isolating its cdna from a human liver cdna library. the cdna for human alpha ttp predicts 278 amino acids with a calculated molecular mass of 31,749, and the sequence exhibits 94% similarity with rat alpha ttp at the amino acid leve ...19957887897
cloning and characterisation of multiple acetyl-coa carboxylase transcripts in ovine adipose tissue.a full-length ovine acetyl-coa carboxylase-encoding cdna (acc) has been cloned from adipose tissue and completely sequenced. the open reading frame of 7041 nucleotides (nt) is highly homologous to the previously cloned human, rat, chicken, yeast and algal acc (85, 89, 82, 54 and 54% identity, respectively). transcript heterogeneity was found in the 5' and 3' untranslated regions (utr) resulting in acc transcripts in the range of 9.0 kb to 9.4 kb. heterogeneity at the 5' end was generated by the ...19957890176
reconstituted nuclei depleted of a vertebrate glfg nuclear pore protein, p97, import but are defective in nuclear growth and replication.xenopus egg extracts provide a powerful system for in vitro reconstitution of nuclei and analysis of nuclear transport. such cell-free extracts contain three major n-acetylglucosaminylated proteins: p200, p97, and p60. both p200 and p60 have been found to be components of the nuclear pore. here, the role of p97 has been investigated. xenopus p97 was isolated and antisera were raised and affinity purified. immunolocalization experiments indicate that p97 is present in a punctate pattern on the nu ...19957876300
the functional expression of a rat cdna encoding oscp in the yeast saccharomyces cerevisiae.the oligomycin sensitivity conferring protein (oscp) of saccharomyces cerevisiae is a component of the stalk fa sector of the mitochondrial f1fo-atp synthase complex (mtatpase). the subunits comprising this sector have been implicated in the coupling of proton flux through the membrane fo sector to atp synthesis on the catalytic f1 sector. we tested whether the yeast subunit encoded by the atp5 gene could be functionally replaced by a mammalian homologue, rat oscp. the yeast and rat oscp protein ...19957864899
p115 is a general vesicular transport factor related to the yeast endoplasmic reticulum to golgi transport factor uso1p.a recently discovered vesicular transport factor, termed p115, is required along with n-ethylmaleimide-sensitive fusion protein (nsf) and soluble nsf attachment proteins for in vitro golgi transport. p115 is a peripheral membrane protein found predominantly on the golgi. biochemical and electron microscopic analyses indicate that p115 is an elongated homodimer with two globular "heads" and an extended "tail" reminiscent of myosin ii. we have cloned and sequenced cdnas for bovine and rat p115. th ...19957831323
nucleotide binding by the synapse associated protein sap90.the rat synapse associated protein sap90 is a member of a superfamily of potential guanylate kinases localized at cell-cell contact sites. this superfamily includes the synapse associated protein sap97, a close relative of sap90, the drosophila tumor suppressor gene product dlg-ap, the mammalian zonula occludens proteins zo-1 and zo-2 and the erythrocyte protein p55. here we show that sap90 specifically binds gmp in the micromolar range while binding to atp, gdp and adp is at a much lower affini ...19957867790
cloning and identification of amino acid residues of human phospholipase c delta 1 essential for catalysis.in vitro single point mutagenesis, inositol phospholipid hydrolysis, and substrate protection experiments were used to identify catalytic residues of human phosphatidylinositide-specific phospholipase c delta 1 (plc delta 1) isolated from a human aorta cdna library. invariant amino acid residues containing a functional side chain in the highly conserved x region were changed by in vitro mutagenesis. most of the mutant enzymes were still able to hydrolyze inositol phospholipid with activity rangi ...19957890667
expression of rat cathepsin d cdna in saccharomyces cerevisiae: intracellular sorting of cathepsin d to yeast vacuole. 19958540330
production of rat protein disulfide isomerase in saccharomyces cerevisiae.protein disulfide isomerase (pdi) is an abundant protein of the endoplasmic reticulum that catalyzes the oxidation of protein sulfhydryl groups and the isomerization and reduction of protein disulfide bonds. saccharomyces cerevisiae cells lacking pdi are inviable. pdi is a component of many different protein processing complexes, and the actual activity of pdi that is required for cell viability is unclear. a cdna that codes for rat pdi fused to the alpha-factor pre-pro segment was expressed in ...19958535165
the influence of "selenium organicum" upon the hepatic function of carbon tetrachloride poisoned rats.the hepatoprotective action of the romanian preparation orgasel containing selenium (se) 5.01 mg/100 g autolysated yeast powder, was tested on adult wistar rats poisoned with carbon tetrachloride (ccl4). the hepatotoxic agent (a 20% ccl4 solution in oil) was administered i.p. in a single dose of 0.3 ml ccl4 solution/100 g body weight, and the preparation tested (autolysate of seleniated yeast) was administered by gavage in 4 doses (of 100 mg se powder/100 g animal each) along 2 days. after 48 hr ...19958535346
cloning and characterization of a putative calcium-transporting atpase gene from schistosoma mansoni.complementary dna was isolated, encoding a putative ca(2+)-transport atpase (sma1) of the human parasitic trematode schistosoma mansoni. the cdna was isolated by a nested polymerase chain reaction based strategy. the oligonucleotides used were designed on the basis of conserved amino-acid regions found in p-type atpases. the complete nucleotide sequence was determined. the primary structure and topology of the enzyme were deduced. sma1 has 1022 amino acids and a predicted molecular mass of 113 k ...19958538684
[dynamics of luminol-dependent chemiluminescence in rat whole blood at different oxygen concentrations].chemiluminescence analysis was used to examine the yeast cell-activation of rat whole blood neutrophilic leukocytes in rats after their pre-exposure to 3-hour hypoxia (9,000 m above sea level) and two-hour hyperoxia (0.3 mpa), as well as their resultant effects. the hypoxia was found to cause a significant (42%) reduction in the length of the latent period, suggesting that it activates the phagocytic activity of neutrophilic leukocytes. at the same time hyperoxia leads to a delayed response of c ...19958553626
nuclear pore complex clustering and nuclear accumulation of poly(a)+ rna associated with mutation of the saccharomyces cerevisiae rat2/nup120 gene.to identify genes involved in the export of messenger rna from the nucleus to the cytoplasm, we used an in situ hybridization assay to screen temperature-sensitive strains of saccharomyces cerevisiae. this identified those which accumulated poly(a)+ rna in their nuclei when shifted to the non-permissive temperature of 37 degrees c. we describe here the properties of yeast strains carrying mutations in the rat2 gene (rat - ribonucleic acid trafficking) and the cloning of the rat2 gene. only a low ...19958557737
human glucokinase regulatory protein (gckr): cdna and genomic cloning, complete primary structure, and chromosomal localization.null mutations in the glucokinase (gck) gene can cause autosomal dominant type 2 diabetes (maturity onset diabetes of the young, mody); however, mody is genetically heterogeneous. in both liver and pancreatic islet, glucokinase is subject to inhibition by a regulatory protein (gckr). given the role of gck in mody, gckr is itself a candidate type 2 diabetes susceptibility gene. here we describe the structure of full-length (2.2 kb) cdna for human gckr, from the hepatoblastoma cell line hepg2. the ...19958589523
prohibitin: potential role in senescence, development, and tumor suppression.prohibitin is an evolutionarily conserved gene with homologues found in organisms ranging from yeast to man. in man the gene is located on chromosome 17 at q21. the deduced amino acid sequences of the protein products from mouse and rat are identical; and these differ from the human protein sequence by a single conserved amino acid. prohibitin has antiproliferative activity and available data suggest a role in such diverse processes as normal cell cycle regulation, replicative senescence, cellul ...19958591812
identification of a family of closely related human ubiquitin conjugating enzymes.two very closely related human e2 ubiquitin conjugating enzymes, ubfh5b and ubch5c, have been identified. these enzymes are products of distinct genes and are 88-89% identical in amino acid sequence to the recently described human e2, ubch5 (now designated ubch5a), ubch5a-c are homologous to a family of five ubiquitin conjugating enzymes from arabidopsis thaliana, atubc8-12. they are also closely related to saccharomyces cerevisiae scubc4 and scubc5, which are involved in the stress response, an ...19958530467
[time course of amino acid absorption in growing rats after feeding of a 15n-labeled wheat/yeast ration].the time course of aa digestion, aa balance (sv as), and aa absorption (wv as) was estimated on growing rats (wistar rats, lw = 124 g) in different sections of the intestinal tract using the combination of 15n tracer and tio2 marker techniques. the animals received once a diet of 15n labelled wheat and yeast as protein sources supplemented by tio2 as a marker. up to 6 h after feeding the amino acid composition the 15n excess and the tio2 content in the digesta of stomach, small and large intesti ...19958526730
Refresh
firstprev
12345678910...
nextlast
Displaying items 801 - 900 of 2172