| prohormone-converting enzymes: regulation and evaluation of function using antisense rna. | several putative peptide-processing endoproteases have been identified by homology to the yeast kex2 endoprotease, including furin, pc2, and pc1. however, the question is still open as to which might be involved in peptide posttranslational processing. to enable detailed comparisons of physiological changes in peptide processing with biochemical and molecular biological studies, we cloned rat pituitary cdnas for pc1 and pc2. the amino acid sequence homologies among rat, human, and mouse pc1, pc2 ... | 1991 | 1791845 |
| 1h and 15n nmr study of human lysozyme. | the 15n signal assignment of human lysozyme was carried out by using 1h-1h and 1h-15n two dimensional experiments. to solve the severe overlap problem of the nh signals, uniform labeling of the protein with 15n was introduced. the uniformly 15n labeled protein was prepared using a high-expression system of saccharomyces cerevisiae. from the analyses of 1h and 15n nmr spectra, all of the backbone 15n signals of the molecule were assigned to each specific residue in the amino acid sequence. recent ... | 1991 | 1794972 |
| stimulation of human neutrophil phagocytosis of candida albicans by a beta-glucan synthase inhibitor, cilofungin. | the effect of a lipopeptide antifungal agent, cilofungin, on serum opsonization and phagocytosis of candida albicans yeast phase cells in human neutrophil monolayer assays was investigated. simultaneous addition of fungicidal concentrations of cilofungin did not enhance or inhibit phagocytosis of c. albicans. pretreatment of candida blastospores with cilofungin in the absence of serum complement for 1 h did not affect phagocytosis. however, pretreatment of blastospores with cilofungin and comple ... | 1991 | 1797051 |
| generation of 5-fluorouracil from 5-fluorocytosine by monoclonal antibody-cytosine deaminase conjugates. | cytosine deaminase (cdase) catalyzes the conversion of cytosine to uracil and is also able to convert the clinically used antifungal agent 5-fluorocytosine (5fc) into the anticancer drug 5-fluorouracil (5fu). the enzyme was purified from bakers' yeast in a six-step procedure. studies indicated that bakers' yeast cdase had a molecular weight of approximately 32 kda and was composed of two subunits of equal molecular weights. monoclonal antibodies were covalently attached to cdase, forming conjuga ... | 1991 | 1805942 |
| [regulation of ca(2+)-dsrna for proliferation and terminal differentiation processes of human fibroblasts and hela cells]. | ca2+ complexes of dsrna, poly(da) and poly(dt) of yeast low molecular weight rna produce a pronounced mitogenic effect on human fibroblasts at early stages of fibroblast proliferation in culture. at later stages of cell cultivation ca(2+)-dsrna stimulates terminal differentiation by inducing the synthesis of proteins characteristic of the postmitotic population of human fibroblasts undergoing terminal differentiation. ca(2+)-dsrna produces a stimulating effect on c-fos and c-jun gene transcripti ... | 1991 | 1805979 |
| ultrastructural changes induced by alpha-sarcin in a human pulmonary tumor grown in naked mice. | alpha-sarcin is a cytotoxic polypeptide produced by aspergillus giganteus. it suppresses protein synthesis in yeast and wheat germ extracts and has a purine-specific rnase activity. the substance has been tested for its antitumor properties in a series of induced tumor systems in mice such as sarcoma and carcinoma among others. although some of the in vitro effects of alpha-sarcin on certain cellular components have been elucidated, the biological effects leading to cellular damage are still obs ... | 1991 | 1806047 |
| yeast artificial chromosome (yac) clones and sequence tagged site (sts)markers anchored at human chromosome 21. | | 1991 | 1811099 |
| partial purification of a mannosyltransferase involved in the o-mannosylation of glycoproteins from saccharomyces cerevisiae. | the mannosyltransferase that catalyses the transfer of mannose from dolichyl-phosphate-mannose (dol-p-man) to the hydroxyl group of serine/threonine residues in the acceptor peptide (tyr-asn-pro-thr-ser-val) was partially purified approximately 150-fold from the microsomal membrane fraction of saccharomyces cerevisiae. the membrane-bound enzyme was solubilized with 0.5% triton x-100 at a protein:detergent ratio of 2:1, and was then purified by ion-exchange chromatography on deae-cellulose, follo ... | 1991 | 1820198 |
| pas1, a yeast gene required for peroxisome biogenesis, encodes a member of a novel family of putative atpases. | pas genes are required for peroxisome biogenesis in the yeast s. cerevisiae. here we describe the cloning, sequencing, and characterization of the pas1 gene. its gene product, pas1p, has been identified as a rather hydrophilic 117 kd polypeptide. the predicted pas1p sequence contains two putative atp-binding sites and reveals a structural relationship to three other groups of proteins associated with different biological processes such as vesicle-mediated protein transport (nsf and sec18p), cont ... | 1991 | 1825027 |
| a novel cyclin encoded by a bcl1-linked candidate oncogene. | we have previously identified a candidate oncogene (prad1 or d11s287e) on chromosome 11q13 which is clonally rearranged with the parathyroid hormone locus in a subset of benign parathyroid tumours. we now report that a cloned human placental prad1 complementary dna encodes a protein of 295 amino acids with sequence similarities to the cyclins. cyclins can form a complex with and activate p34cdc2 protein kinase, thereby regulating progress through the cell cycle. prad 1 messenger rna levels vary ... | 1991 | 1826542 |
| annexin iii translocates to the periphagosomal region when neutrophils ingest opsonized yeast. | after phagocytosis, killing and digestion of ingested microorganisms depend on fusion of phagocytic vesicle membranes with membranes of intracellular vesicles (azurophil and specific granules). there is considerable evidence that phagosome-granule membrane fusion is regulated by transient increases in intracellular ionized ca2+. in previous studies, we found that a cytosolic ca2(+)-dependent membrane-binding protein, annexin iii, represents over 1% of the total protein of human neutrophils and p ... | 1991 | 1826705 |
| dephosphorylation and activation of a p34cdc2/cyclin b complex in vitro by human cdc25 protein. | oocytes arrested in the g2 phase of the cell cycle contain a p34cdc2/cyclin b complex which is kept in an inactive form by phosphorylation of its p34cdc2 subunit on tyrosine, threonine and perhaps serine residues. the phosphatase(s) involved in p34cdc2 dephosphorylation is unknown, but the product of the fission yeast cdc25+ gene, and its homologues in budding yeast and drosophila are probably positive regulators of the transition from g2 to m phase. we have purified the inactive p34cdc2/cyclin ... | 1991 | 1828290 |
| direct interaction between adenovirus e1a protein and the tata box binding transcription factor iid. | adenovirus e1a has long been known to activate/repress cellular and viral transcription. the transcriptional activity of nuclear extracts was depleted after chromatography on immobilized e1a protein columns that specifically retained the transcription factor (tf) iid. stronger direct interactions between e1a and human tfiid than between e1a and yeast tfiid suggest that the unique sequences of the human protein may be involved. we have demonstrated that this interaction occurs directly between ba ... | 1991 | 1828892 |
| dna sequences of chromosome 21-specific yac detect the t(8;21) breakpoint of acute myelogenous leukemia. | the t(8;21)(q22;q22) is a nonrandom translocation specifically marking blasts of acute myelogenous leukemia (aml) with undifferentiated phenotype. the breakpoint on chromosome 21 involved by this rearrangement has been precisely localized relative to cloned dna markers by physical and genetic linkage analysis enabling the use of positional cloning for its isolation. yeast artificial chromosome (yac) clones for loci proximal (d21s65) and distal (erg) to the (21q22) breakpoint have been developed ... | 1991 | 1756477 |
| [cryptococcal meningitis in aids: successful long-term prophylaxis with fluconazole]. | a 30-year-old, hiv-positive, man who had been repeatedly treated with amphotericin b for oral thrush, developed headaches, fever up to 38.5 degrees c, dizzy spells with falling tendency, as well as disorder of speech and word finding. cerebrospinal fluid (csf) contained 5700/3 cells, of which 90% were encapsulated yeast-fungus. cryptococcal antigen titres were elevated both in serum (1:256) and csf (1:1024), providing the diagnosis of cryptococcal meningitis. intravenous treatment was started wi ... | 1991 | 1756695 |
| variability in commercial histoplasma complement fixation antigens. | using immuno-mycologics (immy; norman, okla.) histoplasmal yeast (hy) and mycelial (hm) antibody complement fixation test antigens, we retested 1,386 samples that were initially tested with meridian diagnostics, inc. (cincinnati, ohio), antigens. histoplasma antibody was identified (greater than or equal to 1:16) in 20% of hy and 5% of hm samples reported to have titers of less than 1:8 with meridian reagents. immy titers were at least fourfold higher than meridian titers in 39% of hy and 54% of ... | 1991 | 1761695 |
| dna polymerase delta: gene sequences from plasmodium falciparum indicate that this enzyme is more highly conserved than dna polymerase alpha. | genes encoding proteins homologous to the catalytic subunits of dna polymerase alpha and delta have been cloned from the human malaria parasite plasmodium falciparum. these are among the first cellular replicative dna polymerase genes to be cloned and their sequences allow us to make new statements about the relative degrees of conservation of these two enzymes. the most important finding was that p. falciparum pol delta showed considerable homology to the only other pol delta enzyme for which p ... | 1991 | 1762904 |
| enhanced phagocytosis and intracellular killing of pityrosporum ovale by human neutrophils after exposure to ketoconazole is correlated to changes of the yeast cell surface. | in seborrhoeic dermatitis an inflammatory response occurs secondary to large numbers of pityrosporum yeasts appearing within and beneath the epidermis. to study the interaction between human neutrophils and p. ovale and any immunomodulating effect of antifungal agents, the yeast was exposed to ketoconazole and then incorporated into neutrophil monolayer assays. phagocytosis was complement dependent and reached a maximum after 40 min. ketoconazole at 25, 50 and 100 mg l-1 had no significant effec ... | 1991 | 1833641 |
| cloning of all-1, the locus involved in leukemias with the t(4;11)(q21;q23), t(9;11)(p22;q23), and t(11;19)(q23;p13) chromosome translocations. | chromosomal region 11q23 participates in a number of reciprocal translocations with specific regions of chromosomes 4, 9, 19, and others. these translocations are associated with acute lymphocytic leukemia and acute myelomonocytic, monocytic, and myelogenous leukemia. from a yeast artificial chromosome containing human dna derived from 11q23 we cloned a dna fragment which can be used as a probe to detect rearrangements in leukemic cells from the majority of patients with the t(4;11), t(9;11), an ... | 1991 | 1835902 |
| mitogenic effect of lysosomal hydrolases on bovine tracheal myocytes in culture. | studies were conducted to assess the mitogenic effect of lysosomal hydrolases, enzymes known to have an association with allergen- or ozone-induced airway hyperreactivity, on bovine tracheal myocytes in culture. addition of purified human placental beta-hexosaminidase and partially purified bovine liver beta-glucuronidase resulted in the doubling of cell count after 4 d of incubation in medium m199 with 0.4% fbs. unstimulated cells remained quiescent without a significant increase of cell count. ... | 1991 | 1836469 |
| phosphorylation of replication protein a: a role for cdc2 kinase in g1/s regulation. | | 1991 | 1840253 |
| screening a yeast promoter library leads to the isolation of the rp29/l32 and snr17b/rpl37a divergent promoters and the discovery of a gene encoding ribosomal protein l37. | two promoters (a7 and a23), isolated at random from the saccharomyces cerevisiae genome by virtue of their capacity to activate transcription, are identical to known intergenic bidirectional promoters. sequence analysis of the genomic dna adjacent to the a7 promoter identified a split gene encoding ribosomal (r) protein l37, which is homologous to the trna-binding r-proteins, l35a (from human and rat) and l32 (from frogs). | 1991 | 1840541 |
| torulopsis candida (candida famata) endophthalmitis simulating propionibacterium acnes syndrome. | four months after undergoing extracapsular cataract extraction with implantation of a posterior chamber intraocular lens, a 74-year-old woman developed granulomatous anterior uveitis. although she initially responded well to corticosteroid therapy, she experienced multiple recurrences on discontinuation of this therapy. slit-lamp examination showed the ocular inflammation to be associated with white cortical material within the lens capsular sac. she underwent removal of the implant as well as t ... | 1991 | 1841584 |
| furin: the prototype mammalian subtilisin-like proprotein-processing enzyme. endoproteolytic cleavage at paired basic residues of proproteins of the eukaryotic secretory pathway. | furin, the translational product of the recently discovered fur gene, appears to be the first known mammalian member of the subtilisin family of serine proteases and the first known mammalian proprotein-processing enzyme with cleavage selectivity for paired basic amino acid residues. structurally and functionally, it resembles the prohormone-processing enzyme, kexin (ec 3.4.21.61), which is encoded by the kex2 gene of yeast saccharomyces cerevisiae. most likely, furin is primarily involved in th ... | 1991 | 1843280 |
| increase in the expression of a family of small guanosine triphosphate-binding proteins, rab proteins, during induced phagocyte differentiation. | rab is a newly identified family of small g-proteins that share 35-70% homology with the yeast sec4p and ypt1p involved in the regulation of the secretory pathway. mature phagocytes display functions requiring organized intracellular traffic and, for this reason, we questioned whether phagocyte differentiation could correlate with the increased expression of rab proteins. rabbit antisera raised against the recombinant proteins rab1ap, 2p, 4p, and 6p were able to detect the corresponding proteins ... | 1991 | 1847940 |
| expression of human papillomavirus proteins in yeast saccharomyces cerevisiae. | the l1 and l2 proteins of human papillomavirus (hpv) types 1, 6, and 16 and the e6 and e7 proteins of hpv 16 were expressed in saccharomyces cerevisiae. the yeast expressed proteins were readily detected by immune blotting and were generally intact. the hpv 1 l1 and l2 proteins expressed in yeast were indistinguishable from the major and minor capsid proteins purified from hpv 1 virions as judged by gel electrophoresis and immunoblotting. the hpv 6 and hpv 16 l2 proteins and hpv 16 e7 proteins w ... | 1991 | 1850917 |
| activation of the camp cascade by steroidogenic hormones and glucagon in the pathogenic fungus candida albicans. | incubation of candida albicans yeast cells with human luteinizing hormone (hlh), human chorionic gonadotrophin (hcg) or glucagon produced a significant rise in camp total levels. the effect of these hormones in permeabilized cells of the fungus produced a 2-3 fold increase in the mg2+, gtp-dependent adenylyl cyclase activity as well as full activation of the camp-dependent protein kinase (pka) activity. these results indicate that the interaction of the mammalian hormones with the fungus trigger ... | 1991 | 1851467 |
| chromatography of selenoproteins in human serum using matrix-bound heparin. | since previous experiments indicated that a major selenoprotein in human serum interacts with heparin, chromatography of serum on matrix-bound heparin was studied. when human serum was applied to heparin-agarose columns, approximately half of the applied selenium was not retained on the columns. approx. 40% of the selenium could then be eluted either with increasing concentrations of heparin or ammonium acetate. using a scaled-down version of this procedure, selenoproteins from 0.5 ml serum were ... | 1991 | 1856049 |
| phagocytosis of opsonized yeast induces tumor necrosis factor-alpha mrna accumulation and protein release by human polymorphonuclear leukocytes. | in this report we show that phagocytosis of yeast particles opsonized with igg (y-igg) by human polymorphonuclear cells (pmn) results in the selective induction of tumor necrosis factor (tnf-alpha) messenger rna (mrna) and release of its mature protein. lipopolysaccharide (lps) was also found able to induce tnf-alpha secretion by pmn, but was a less potent stimulus compared with y-igg. there was no evidence of interleukin-6 (il-6) gene expression in pmn after phagocytosis of y-igg or in response ... | 1991 | 1856593 |
| separation of human liver microsomal tolbutamide hydroxylase and (s)-mephenytoin 4'-hydroxylase cytochrome p-450 enzymes. | purification and immunoinhibition studies have suggested that the hydroxylations of (s)-mephenytoin and tolbutamide are catalyzed by rather similar forms of human liver cytochrome p-450 (p-450). however, the two activities are not well correlated in vivo; sulfaphenzaole is a selective inhibitor of tolbutamide hydroxylation, and expression of p-450 2c10 cdna in yeast yields a protein that hydroxylates tolbutamide but not (s)-mephenytoin. the p-450 2c8, 2c9, and 2c10 cdnas have all been isolated, ... | 1991 | 1857342 |
| characterization of a maize cdna that complements an enolase-deficient mutant of escherichia coli. | a cdna encoding maize enolase (2-phospho-d-glycerate hydrolase) was purified by functional genetic complementation using an enolase deficient mutant of escherichia coli, df261. this cdna, pzm245, was characterized by restriction mapping and dna sequence analysis. the cdna contained an open reading frame encoding a protein of 446 amino acids with a high degree of similarity to enolase sequences from other organisms (72% identity to yeast enolase and 82% identity to human enolase). the pzm245 cont ... | 1991 | 1859865 |
| cryosurvival of trichomonas vaginalis during cryopreservation of human semen. | despite a 90% cryosurvival of trichomonas vaginalis in their growth medium trypticase yeast maltose (tym) with dmso, none of these parasites have previously been observed to survive during cryopreservation of infected human semen with glycerol (andrologia 18, 323 (1986)). this could have been due to the failure of the culture method used to detect low numbers of survivors. the prospects of possible transmission of t. vaginalis by artificial insemination with cryobanked (-196 degrees c) semen pro ... | 1991 | 1864083 |
| differential expression of two types of the neurofibromatosis type 1 (nf1) gene transcripts related to neuronal differentiation. | a 360 residue region encoded by the neurofibromatosis type 1 (nf1) gene shows significant homology to the catalytic domains of both mammalian gtpase-activating proteins (gap) and yeast ira proteins. this gap-related domain of the nf1 gene (nf1-grd), like the gap and ira protein, has been reported to mediate hydrolysis of ras-bound gtp to gdp, resulting in inactivation of ras protein. in the present study, we identified two different types of nf1-grd cdna. one (type i) is identical to the previou ... | 1991 | 1923522 |
| a rat brain mrna encoding a transcriptional activator homologous to the dna binding domain of retroviral integrases. | we have isolated a rat cdna, named fe65, hybridizing to an mrna of about 2,300 nucleotides present in rat brain, undetectable in rat liver and very poorly represented in other tissues. an mrna of the same size is present in human neuroblastoma cells and is absent from other human cell lines. the fe65 cdna contains an open reading frame (orf) coding for a polypeptide of 499 amino acids in which 143 residues can be aligned with the dna binding domain of the integrases encoded by mammalian immunode ... | 1991 | 1923810 |
| phylogenetic analysis of five medically important candida species as deduced on the basis of small ribosomal subunit rna sequences. | the classification of species belonging to the genus candida berkhout is problematic. therefore, we have determined the small ribosomal subunit rna (srrna) sequences of the type strains of three human pathogenic candida species; candida krusei, c. lusitaniae and c. tropicalis. the srrna sequences were aligned with published eukaryotic srrna sequences and evolutionary trees were inferred using a matrix optimization method. an evolutionary tree comprising all available eukaryotic srrna sequences, ... | 1991 | 1865186 |
| cloning and characterization of a 3-methyladenine dna glycosylase cdna from human cells whose gene maps to chromosome 16. | we described previously the isolation of a saccharomyces cerevisiae 3-methyladenine (3-meade) dna glycosylase repair gene (mag) by its expression in glycosylase-deficient escherichia coli alka tag mutant cells and its ability to rescue these cells from the toxic effects of alkylating agents. here we extend this cross-species functional complementation approach to the isolation of a full-length human 3-meade dna glycosylase cdna that rescues alka tag e. coli from killing by methyl methanesulfonat ... | 1991 | 1924375 |
| a case of trichosporon pullulans infection of the lung with adult t-cell leukemia. | fungal infections are often reported, but trichosporon infection is very rare. a 78-year-old man with adult t-cell leukemia complicated with pulmonary infections is presented. bronchial exudate culture revealed many yeast-like colonies, which were morphologically and biochemically identified as trichosporon pullulans. | 1991 | 1865584 |
| analysis of yeast prp20 mutations and functional complementation by the human homologue rcc1, a protein involved in the control of chromosome condensation. | mutations in the prp20 gene of yeast show a pleiotropic phenotype, in which both mrna metabolism and nuclear structure are affected. srm1 mutants, defective in the same gene, influence the signal transduction pathway for the pheromone response. the yeast prp20/srm1 protein is highly homologous to the rcc1 protein of man, hamster and frog. in mammalian cells, this protein is a negative regulator for initiation of chromosome condensation. we report the analysis of two, independently isolated, rece ... | 1991 | 1865879 |
| human infection caused by exophiala pisciphila: case report and review. | one year after receiving a liver transplant and 2 months after treatment with high doses of steroids and monoclonal anti-cd3 for an episode of rejection, a 38-year-old woman developed a skin papule above the left medial malleolus. the papule, which at first had an annular shape, evolved into a pustule, ulcerated, drained, and assumed a crusted verrucous appearance. multiple satellite papules appeared around the lesion, which was incompletely excised and thought to represent squamous cell carcino ... | 1991 | 1866539 |
| secretion of n-glycosylated interleukin-1 beta in saccharomyces cerevisiae using a leader peptide from candida albicans. effect of n-linked glycosylation on biological activity. | human interleukin-1 beta (il-1 beta) is expressed in activated monocytes as a 31-kda precursor protein which is processed and secreted as a mature, unglycosylated 17-kda carboxyl-terminal fragment, despite the fact that it contains a potential n-linked glycosylation site near the nh2 terminus (-asn7-cys8-thr9-). cdna coding for authentic mature il-1 beta was fused to the signal sequence from the candida albicans glucoamylase gene, two amino acids downstream from the signal processing site. upon ... | 1991 | 1869556 |
| [1-14c]oleate-labeled autoclaved yeast: a membranous substrate for measuring phospholipase a2 activity in vitro. | radiolabeled, autoclaved yeast were tested as a substrate for mammalian phospholipase a2 activity because the only other membranous substrate used for this purpose, autoclaved escherichia coli, totally lacks a major mammalian phospholipid, phosphatidylcholine. candida albicans were grown in the presence of [1-14c]oleate and then autoclaved. sixty three percent of the incorporated label was in yeast phospholipid, and more than 95% of that was in the 2-acyl position. the distribution of label in t ... | 1991 | 1872466 |
| both oct-1 and oct-2a contain domains which can activate the ubiquitously expressed u2 snrna genes. | the u2 snrna genes, which are transcribed by rna polymerase ii at high levels in all tissues examined, require both a distal and a proximal sequence element for efficient expression. the distal sequence element which has many properties in common with transcriptional enhancers contains, in addition to sp1 binding sites, an octamer binding site which mediates activation through interactions with the ubiquitous transcription factor oct-1. in the present study we have attempted to answer the questi ... | 1991 | 1829677 |
| human uracil-dna glycosylase complements e. coli ung mutants. | we have previously isolated a cdna encoding a human uracil-dna glycosylase which is closely related to the bacterial and yeast enzymes. in vitro expression of this cdna produced a protein with an apparent molecular weight of 34 k in agreement with the size predicted from the sequence data. the in vitro expressed protein exhibited uracil-dna glycosylase activity. the close resemblance between the human and the bacterial enzyme raised the possibility that the human enzyme may be able to complement ... | 1991 | 1886771 |
| mitochondrial activity and cytotoxicity of vitamin a (retinol) in yeast and human cell cultures. protective effect of antioxidants. | vitamin a inhibited the growth of yeast and human cells in a dose-dependent but selective manner in cultures utilizing a non-fermentable carbon and energy source. at sub-inhibitory concentrations in yeast cultures (approximately 100 micrograms/ml), the vitamin had a stimulatory effect on the mitochondrial system, foreshortening the lag phase in the adaptation to non-fermentable substrate. at inhibitory concentrations, vitamin a depressed mitochondrial protein synthesis relative to cytoplasmic pr ... | 1991 | 1888332 |
| rapid screening of a yac library by pulsed-field gel southern blot analysis of pooled yac clones. | a new method for screening of yac libraries is described. individual yacs were pooled into groups of 384 clones and prepared as samples suitable for pulsed-field gel electrophoresis. a five hit human yac library (brownstein et al., 1989) containing approximately 60,000 clones was condensed into 150 such pools and chromosomal dnas in each sample were separated on three pulsed field gels containing 50 samples each. southern blots prepared from these gels were hybridized with probes of interest to ... | 1991 | 1889812 |
| [therapy of hiv infection (aids)]. | the stages of human immunodeficiency viruses (hiv) life cycle are described as guide to therapeutic intervention. practical therapeutic recommendations are given. they should be directed to viruses as the causal agent and to the features of opportunistic infections as well as of associated malignant tumors. recently 3 progresses could be reached: (1) the application of azidothymidine in the latency phase, when the number of cd4 positive cells decreases below 500/mm3, whereby the progression of t ... | 1991 | 1897284 |
| molecular characterization of two galactosemia mutations: correlation of mutations with highly conserved domains in galactose-1-phosphate uridyl transferase. | galactosemia is an autosomal recessive disorder of human galactose metabolism caused by deficiency of the enzyme galactose-1-phosphate uridyl transferase (galt). the molecular basis of this disorder is at present not well understood. we report here two missense mutations which result in low or undetectable enzymatic activity. first, we identified at nucleotide 591 a transition which substitutes glutamine 188 by arginine. the mutated glutamine is not only highly conserved in evolution (conserved ... | 1991 | 1897530 |
| molecular cloning, structure and expression of the yeast proliferating cell nuclear antigen gene. | the budding yeast saccharomyces cerevisiae is proving to be an useful and accurate model for eukaryotic dna replication. it contains both dna polymerase alpha (i) and delta (iii). recently, proliferating cell nuclear antigen (pcna), which in mammalian cells is an auxiliary subunit of dna polymerase delta and is essential for in vitro leading strand sv40 dna replication, was purified from yeast. we have now cloned the gene for yeast pcna (pol30). the gene codes for an essential protein of 29 kda, ... | 1990 | 1970160 |
| inhibition of intracellular growth of histoplasma capsulatum yeast cells by cytokine-activated human monocytes and macrophages. | human monocytes/macrophages (m psi) were infected with histoplasma capsulatum yeast cells, and intracellular growth was quantified after 24 h of incubation in medium alone or in medium containing cytokines. yeast cells multiplied within freshly isolated monocytes, cultured m psi, and alveolar m psi with intracellular generation times of 14.2 +/- 1.4, 18.5 +/- 2.1, and 19.9 +/- 1.9 h (mean +/- standard error of the mean), respectively. monocytes and m psi inhibited the intracellular growth of yea ... | 1991 | 1898916 |
| the yeast homolog to mouse tcp-1 affects microtubule-mediated processes. | a saccharomyces cerevisiae homolog to drosophila melanogaster and mouse tcp-1 encoding tailless complex polypeptide 1 (tcp1) has been identified, sequenced, and mapped. the mouse t complex has been under scrutiny for six decades because of its effects on embryogenesis and sperm differentiation and function. tcp1 is an essential gene in yeast cells and is located on chromosome 4r, linked to pet14. the tcp1-encoded proteins in yeast, drosophila, and mouse cells share between 61 and 72% amino acid ... | 1991 | 1901944 |
| analyzing the substrate specificity of saccharomyces cerevisiae myristoyl-coa:protein n-myristoyltransferase by co-expressing it with mammalian g protein alpha subunits in escherichia coli. | a dual plasmid system was used to examine the protein and acyl-coa specificities of saccharomyces cerevisiae myristoyl-coa:protein n-myristoyltransferase (nmt) by co-expressing it in escherichia coli with each of four homologous alpha subunits of the signal-transducing, heterotrimeric g proteins. exogenous [3h]myristate was incorporated into rat gi alpha 1 and rat go alpha but not into bovine gs alpha or human gz alpha. oxygen for methylene group substitutions in myristate result in analogs with ... | 1991 | 1903791 |
| sera from patients with colon, breast and lung cancer induce resistance to lysis mediated by nk cytotoxic factors (nkcf). | natural killer (nk) cells are involved in the antitumoral immunologic mechanism. these cells act through the release of cytotoxic molecules defined as nk cytotoxic factors (nkcf). inhibitory factors of nk and nkcf mediated lysis have been described in in vitro assays. this study evaluates the induction of resistance to nkcf cytotoxicity by sera from 27 patients with colon, breast and lung cancer. addition of these sera to the cytolytic assay where k562 cells and concentrated nkcf were used, indu ... | 1991 | 1906292 |
| resolution of a low molecular weight g protein in neutrophil cytosol required for nadph oxidase activation and reconstitution by recombinant krev-1 protein. | activation of the membrane-associated nadph oxidase in intact human neutrophils requires a receptor-associated heterotrimeric gtp-binding protein that is sensitive to pertussis toxin. activation of this nadph oxidase by arachidonate in a cell-free system requires an additional downstream pertussis toxin-insensitive g protein (gabig, t. g., english, d., akard, l. p., and schell, m. j. (1987) (j. biol. chem. 262, 1685-1690) that is located in the cytosolic fraction of unstimulated cells (gabig, t. ... | 1991 | 1906890 |
| assessment of the transcriptional activation potential of the hmg chromosomal proteins. | chromosomal proteins hmg-14, hmg-17, and hmg-1 are among the most abundant, ubiquitous, and evolutionarily conserved nonhistone proteins. analysis of their structure reveals features which are similar to those of certain transcription factors. the distribution of charged amino acid residues along the polypeptide chains is asymmetric: positive charges are clustered toward the n-terminal region, while negative charges are clustered toward the c-terminal region. the residues in the c-terminal regio ... | 1991 | 1908554 |
| rsr1 and rap1 gtpases are activated by the same gtpase-activating protein and require threonine 65 for their activation. | the rsr1 protein of saccharomyces cerevisiae has been shown to be essential for bud site selection (bender, a., and pringle, j. (1989) proc. natl. acad. sci. u.s.a. 86, 9976-9980). this protein of 272 amino acids shares approximately 50% sequence identity with both ras and rap gtpases. however, neither gtp binding nor gtpase activity of the rsr1 protein has been reported. the rsr1 protein shares with human rap1 gtpases the four specific motifs, i.e. gly-12, residues 32-40, ala-59, and residues 6 ... | 1991 | 1910037 |
| why yeast? | yeast is an apparently strange "model" for the human genome, but it works because of the high degree of conservation in evolution between the primitive eukaryote and mammals. moreover, the genic concentration in yeast--with almost no noncoding introns--packs the entire yeast genome into 16 chromosomes with only 10% of the dna of one human chromosome. | 1991 | 1918194 |
| [mass spectrometric structure analysis of fatty acid mixtures from biological material after gas capillary chromatographical separation]. | the identification of mixtures of fatty acids from biological materials is possible by electron impact ionization mass spectra of methyl esters after their capillary gas chromatographic separation. mass spectra of pyrrolidine derivatives are used for the determination of double bond positions in unsaturated fatty acids. 97 different fatty acids (saturated, unsaturated, branched, cyclic, hydroxy, oxo, epoxy and methoxy) and other compounds (alkanes, halogens, phthalates, ketones, aldehydes) were ... | 1991 | 1922276 |
| the human homologous pairing protein hpp-1 is specifically stimulated by the cognate single-stranded binding protein hrp-a. | homologous pairing and strand exchange of dna are catalyzed by the human homologous pairing protein hpp-1 in a magnesium-dependent, atp-independent reaction that requires homologous dna substrates and stoichiometric quantities of hpp-1. here we show that the addition of the purified human single-strand binding (ssb) protein hrp-a to the reaction mixture stimulates the rate of homologous pairing 70-fold and reduces the amount of hpp-1 required for the reaction at least 10-fold. the identification ... | 1991 | 1924369 |
| sequence requirements for proteolytic cleavage of precursors with paired basic amino acids. | when expressed in cos cells, human prorenin was secreted into the medium without being processed to an active renin. co-expression of furin, a mammalian homologue of the yeast kex2 gene product, did not affect proteolytic processing of prorenin. a mutant proreninr-4 constructed by site-directed mutagenesis of pro (-4) to arg was not cleaved by an endoprotease in the cos cell. however, proreninr-4 was detectably cleaved to yield the active renin upon co-transfection with furin dna, indicating tha ... | 1991 | 1930163 |
| phosphoglucoisomerase-catalyzed interconversion of hexose phosphates. a model for d-[2-3h]glucose metabolism in human erythrocytes. | when d-[2-3h]glucose 6-phosphate mixed with the unlabeled ester is converted to d-[1-3h]fructose 6-phosphate and 3hoh in the phosphoglucoisomerase reaction and then to d-[1-3h]fructose 1,6-bisphosphate in the phosphofructokinase reaction, the specific radioactivity of the latter metabolite and the production of 3hoh relative to the total generation of tritiated end products are both inversely related to the concentration of phosphofructokinase. in human erythrocytes, the modeling of d-[2-3h]gluc ... | 1991 | 1931158 |
| human recombinant granulocyte-macrophage colony-stimulating factor augments viability and cytotoxic activities of human monocyte-derived macrophages in long-term cultures. | in the present study we investigated the effect of human recombinant granulocyte-macrophage csf (gm-csf) on the in vitro maturation of human monocytes into macrophages, and followed the biochemical and functional changes in the cells during this process. adherent human peripheral blood monocytes cultured for up to 3 weeks in the presence of gm-csf were examined for viability and adherence, beta-glucosaminidase activity, oxidative burst activity, expression of fucosyl-mannosyl receptors, and tnf- ... | 1991 | 1932369 |
| radiochemical assay of adenylosuccinase: demonstration of parallel loss of activity toward both adenylosuccinate and succinylaminoimidazole carboxamide ribotide in liver of patients with the enzyme defect. | a radiochemical assay for adenylosuccinase, an enzyme which intervenes twice in the biosynthesis of adenine nucleotides, has been developed. the two substrates of the enzyme, succinylaminoimidazole carboxamide ribotide (saicar) and adenylosuccinate (s-amp), were synthesized in radioactive form by incubating [2,3-14c]fumarate and, respectively, aicar and amp with partially purified adenylosuccinase from yeast. enzyme activities were determined by measuring the release of labeled fumarate after it ... | 1991 | 1872474 |
| a wild-type dna ligase i gene is expressed in bloom's syndrome cells. | alteration of dna ligase i activity is a consistent biochemical feature of bloom's syndrome (bs) cells. dna ligase i activity in bs cells either is reduced and abnormally thermolabile or is present in an anomalously dimeric form. to assess the role of dna ligase function in the etiology of bs, we have cloned the dna ligase i cdna from normal human cells by a pcr strategy using degenerate oligonucleotide primers based on conserved regions of the saccharomyces cerevisiae and schizosaccharomyces po ... | 1991 | 1881902 |
| sar1, a gene from schizosaccharomyces pombe encoding a protein that regulates ras1. | proper ras1 function is required for normal sexual function in the yeast schizosaccharomyces pombe. we have found a gene in s. pombe, sar1, that encodes a product capable of regulating ras1 function. sar1 is a member of an expanding family of ras gtpase-activating proteins (gaps) that includes mammalian gap, the yeast saccharomyces cerevisiae ira proteins, and the product of the human neurofibromatosis locus, nf1 sar1, like these other proteins, can complement the loss of ira function in s. cere ... | 1991 | 1883874 |
| thermostabilization of recombinant human and bovine cuzn superoxide dismutases by replacement of free cysteines. | human cuzn superoxide dismutase (hsod) has two free cysteines: a buried cysteine (cys6) located in a beta-strand, and a solvent accessible cysteine (cys111) located in a loop region. the highly homologous bovine enzyme (bsod) has a single buried cys6 residue. cys6 residues in hsod and bsod were replaced by alanine and cys111 residues in hsod by serine. the mutant enzymes were expressed and purified from yeast and had normal specific activities. the relative resistance of the purified proteins to ... | 1991 | 1958215 |
| molecular analysis of the ets genes and their products. | organisms from human to drosophila have been found to contain cellular sequences and transcripts that are homologous to the ets region of the avian retrovirus, e26. ets-related sequences are present on at least two distinct functional loci in chickens and mammals, and have been designated ets-1 and ets-2. the e26 virus transduced sequences from the chicken ets-1 locus, which encompasses over 60 kb of dna. the ets genes characterized so far from sea urchin and drosophila are most closely related ... | 1990 | 1964597 |
| development of antibodies to unprotected glycosylation sites on recombinant human gm-csf. | in 4 out of 16 patients receiving recombinant human granulocyte macrophage colony stimulating factor (rhgm-csf) in phase i/ii studies antibodies developed to the recombinant protein. the antibodies react with sites on the native protein backbone which are normally protected by o-linked glycosylation but which are exposed in rhgm-csf produced in yeast and escherichia coli. antigenicity of recombinant human proteins due to non glycosylation may have relevance to the choice of host system for produ ... | 1990 | 1968169 |
| physical and genetic mapping of polymorphic loci in xq28 (dxs15, dxs52, and dxs134): analysis of a cosmid clone and a yeast artificial chromosome. | sequences corresponding to the xq28 loci dxs15, dxs52, dxs134, and dxs130 were shown to be present in a 140-kb yeast artificial chromosome (yac xy58, isolated by little et al.). this yac clone appears to contain a faithful copy of this genomic region, as shown by comparison with human dna and with a cosmid clone that contains probes st14c (part of the dxs52 sequences) and cpx67 (dxs134). cpx67 and st14c are contained in 11 kb and detect the same mspi rflp polymorphism. a comparison of the yac re ... | 1990 | 1969226 |
| homologous sugar transport proteins in escherichia coli and their relatives in both prokaryotes and eukaryotes. | separate proteins for proton-linked transport of d-xylose, l-arabinose, d-galactose, l-rhamnose and l-fucose into escherichia coli are being studied. by cloning and sequencing the appropriate genes, the amino acid sequences of proteins for d-xylose/h+ symport (xyle), l-arabinose/h+ symport (arae), and part of the protein for d-galactose/h+ symport (galp) have been determined. these are homologous, with at least 28% identical amino acid residues conserved in the aligned sequences, although their ... | 1990 | 1970645 |
| nucleotide sequence of mouse hsp60 (chaperonin, groel homolog) cdna. | the cdna sequence of the 60 kda heat-shock protein from mouse 3t3 cells has been determined. the deduced amino acid sequence of mouse hsp60 protein differs from the corresponding proteins from chinese hamster and human cells in 7 and 13 residues, respectively, most of which are conservative replacements. | 1990 | 1979012 |
| molecular cloning and characterization of interferon alpha/beta response element binding factors of the murine (2'-5')oligoadenylate synthetase me-12 gene. | seven clones encoding interferon response element binding factors have been isolated from a mouse fibroblast lambda gt11 cdna library by using a 32p end-labeled tandem trimer of the mouse (2'-5')oligoadenylate synthetase gene interferon response element as a probe. clone 16 shares strong similarity (95%) at both dna and amino acid level with yb-1, a human major histocompatibility complex class ii y-box dna-binding protein, and with dbpb, a human epidermal growth factor receptor gene enhancer reg ... | 1991 | 1986360 |
| covalent structure, disulfide bonding, and identification of reactive surface and active site residues of human prostatic acid phosphatase. | the pairing of the half-cysteine residues of human prostatic acid phosphatase was established by proteolytic digestion and analysis of the resulting peptide mixtures by fast atom bombardment mass spectrometry (fab-ms). an independently derived, full length cdna clone was used as the basis for the interpretation of the fab-ms data. the sequence of the native protein is that predicted from the present cdna sequence, except for the carboxyl-terminal end and some possible post-translational deamidat ... | 1991 | 1989985 |
| in situ hybridization to cytogenetic bands of yeast artificial chromosomes covering 50% of human xq24-xq28 dna. | from the collection described by abidi et al., 102 yeast artificial chromosomes (yacs) with human dna inserts more than 300 kb in length were assigned to chromosomal band positions on early metaphase chromosomes by in situ hybridization using the biotin-avidin method. all the yacs hybridized within the xq24-xqter region, supporting the origin of the vast majority of the yacs from single human x-chromosomal sites. with assignments precise to +/- 0.5 bands, yacs were distributed among cytogenetic ... | 1991 | 1990831 |
| relative efficiencies of the bacterial, yeast, and human dna methyltransferases for the repair of o6-methylguanine and o4-methylthymine. suggestive evidence for o4-methylthymine repair by eukaryotic methyltransferases. | the suicidal inactivation mechanism of dna repair methyltransferases (mtases) was exploited to measure the relative efficiencies with which the escherichia coli, human, and saccharomyces cerevisiae dna mtases repair o6-methylguanine (o6meg) and o4-methylthymine (o4met), two of the dna lesions produced by mutagenic and carcinogenic alkylating agents. using chemically synthesized double-stranded 25-base pair oligodeoxynucleotides containing a single o6meg or a single o4met, the concentration of o6 ... | 1991 | 1993655 |
| further observations on the phagocytosis of candida albicans by hamster and human oocytes. | pathogenic yeast, candida albicans, were incubated with hamster and human oocytes for up to 21 hours in order to determine the nature and time course of phagocytosis of these organisms. aliquotes of the interacting cells were taken at various time intervals for electron microscopic examination. some specimens had their zona pellucidae enzymatically removed prior to incubation with yeast, and these specimens showed the most extensive interaction and phagocytosis of candida. the zona pullucida app ... | 1991 | 1994983 |
| p68 rna helicase: identification of a nucleolar form and cloning of related genes containing a conserved intron in yeasts. | the human p68 protein is an rna-dependent atpase and rna helicase which was first identified because of its immunological cross-reaction with a viral rna helicase, simian virus 40 large t antigen. it belongs to a recently discovered family of proteins (dead box proteins) that share extensive regions of amino acid sequence homology, are ubiquitous in living organisms, and are involved in many aspects of rna metabolism, including splicing, translation, and ribosome assembly. we have shown by immun ... | 1991 | 1996094 |
| conversion of pig pancreas phospholipase a2 by protein engineering into enzyme active against escherichia coli treated with the bactericidal/permeability-increasing protein. | phospholipases a2 (pla-2) are conserved enzymes that can vary widely in their activity toward certain biological targets. activity of pla-2 toward escherichia coli treated with the bactericidal/permeability-increasing protein (bpi) of granulocytes has been detected only in "group ii" pla-2 (lacking cys11-cys77) and correlates with overall basicity and the presence of a cluster of basic amino acids within a variable surface region near the nh2 terminus (including residues 6, 7, 10, 11, and 15). w ... | 1991 | 1999411 |
| effect of soluble aminated beta-1,3-d-polyglucose on human monocytes: stimulation of cytokine and prostaglandin e2 production but not antigen-presenting function. | glucans are insoluble polymers of beta-1,3-linked glucose derived from yeast cell walls that effectively activate macrophages. recently, aminated derivatives of beta-1,3-d-polyglucose have been developed that are soluble but also activate murine macrophages. the current studies were undertaken to determine whether soluble aminated beta-1,3-d-polyglucose (ag) would also stimulate human monocytes. the ag employed contained less than 2 ng endotoxin/mg. ag induced the production of intracellular, me ... | 1991 | 2002282 |
| properties and applications of human dna repair genes. | the importance of understanding dna repair processes is discussed in terms of the origins of human cancer. several human repair genes have been mapped to specific human chromosomes using somatic cell hybrids. it is noteworthy that 3 of these genes lie in the same region of chromosome 19: genes ercc1 and ercc2, which are involved in nucleotide excision repair, and xrcc1, which is involved in the repair of strand breaks. the genes xrcc1 and ercc2 were cloned from cosmid libraries prepared from dna ... | 1991 | 2011139 |
| structural and transcriptional analysis of a human subtelomeric repeat. | a human subtelomeric repeat (designated as the hst repeat) has been isolated and characterized from a yeast artificial chromosome containing one human telomere. this repeat is located immediately adjacent to the telomeric t2ag3 repeats at the extreme termini of the human chromosomes. the dna sequence of 3.6 kb of the hst repeat has been determined. the hst repeat spans over 3.6 kb in length, and contains one evolutionarily conserved cpg-rich region. the copy number of the hst repeat varies among ... | 1991 | 2011494 |
| genetic destabilization of candida albicans by hydroxyurea. | candida albicans is a commensal component of the normal human microflora, but frequently causes infections in persons undergoing treatment for malignancies. the cytotoxicity and genotoxicity of the antineoplastic agent hydroxyurea (hu) for the yeast is demonstrated. cultivation of the organism on defined complete medium in the presence of hu induced growth inhibition or cell death, gene mutations, segregations of heterozygous loci through reciprocal and nonreciprocal mitotic recombinations, and ... | 1991 | 2014007 |
| low-usage codons in escherichia coli, yeast, fruit fly and primates. | codon usage is compared between four classes of species, with an emphasis on characterization of low-usage codons. the classes of species analyzed include the bacterium escherichia coli (eco), the yeast saccharomyces cerevisiae (ysc), the fruit fly drosophila melanogaster (dro), and several species of primates (pri) (taken as a group; includes eleven species for which nucleotide sequence data have been reported to genbank, however, greater than 90% of the sequences were from homo sapiens). the n ... | 1991 | 1937008 |
| alteration of n-terminal residues of mature human lysozyme affects its secretion in yeast and translocation into canine microsomal vesicles. | signal sequences play a central role in the initial membrane translocation of secretory proteins. their functions depend on factors such as hydrophobicity and conformation of the signal sequences themselves. however, some characteristics of mature proteins, especially those of the n-terminal region, might also affect the function of the signal sequences. to examine this possibility, several mutants of human lysozyme modified in the n-terminal region of the mature protein were constructed, and th ... | 1991 | 1939091 |
| catalysis of guanine nucleotide exchange on ran by the mitotic regulator rcc1. | the product of the gene rcc1 (regulator of chromosome condensation) in a bhk cell line is involved in the control of mitotic events. homologous genes have been found in xenopus, drosophila and yeast. a human genomic dna fragment and complementary dna that complement a temperature-sensitive mutation of rcc1 in bhk21 cells encode a protein of relative molecular mass 45,000 (mr 45k) which is located in the nucleus and binds to chromatin. we have recently isolated a protein from hela cells that stro ... | 1991 | 1944575 |
| ocular histoplasmosis with retinitis in a patient with acquired immune deficiency syndrome. | disseminated histoplasmosis is one of the life-threatening opportunistic infections associated with acquired immune deficiency syndrome (aids). a 29-year-old man with aids and disseminated histoplasmosis complained of a hazy spot in the vision of his left eye. results of examination showed distinct creamy white intraretinal and subretinal infiltrates in both eyes. the patient died within a month from pulmonary infection with histoplasma capsulatum and cytomegalovirus. examination with light micr ... | 1991 | 1945308 |
| disseminated histoplasmosis with bilateral adrenal enlargement: diagnosis by computed tomography-directed needle biopsy. | disseminated histoplasmosis is a rare and potentially fatal disease caused by the dimorphic soil fungus histoplasma capsulatum. we describe a 67-year-old man with diabetes who presented with a 6-month history of fever, weight loss, and mental deterioration; using computed tomography (ct), we found hepatosplenomegaly and bilateral adrenal masses. ct-directed adrenal biopsy showed yeast forms consistent with h capsulatum. therapy with ketoconazole was accompanied by adrenal insufficiency (treated ... | 1991 | 2035163 |
| the human hprt gene on a yeast artificial chromosome is functional when transferred to mouse cells by cell fusion. | a 680-kb yeast artificial chromosome (yac) that contains a functional copy of the human hypoxanthine phosphoribosyltransferase (hprt) gene has been isolated. this yac, yhprt, and another yac, yxy837, which contains the 3' end of the hprt gene, have been mapped with restriction enzymes that cleave human dna infrequently. the hprt gene lies near the center of yhprt. fusion of yhprt-containing yeast spheroplasts with mouse l a-9 cells, which are hprt-negative, gives rise to hprt-positive colonies. ... | 1991 | 2037299 |
| the cytosolic and glycosomal glyceraldehyde-3-phosphate dehydrogenase from trypanosoma brucei. kinetic properties and comparison with homologous enzymes. | the protozoan haemoflagellate trypanosoma brucei has two nad-dependent glyceraldehyde-3-phosphate dehydrogenase isoenzymes, each with a different localization within the cell. one isoenzyme is found in the cytosol, as in other eukaryotes, while the other is found in the glycosome, a microbody-like organelle that fulfils an essential role in glycolysis. the kinetic properties of the purified glycosomal and cytosolic isoenzymes were compared with homologous enzymes from other organisms. both trypa ... | 1991 | 2040304 |
| behavior of cysteine mutants of human lysozyme in de novo synthesis and in vivo secretion. | to investigate the mechanism of disulfide-bond-coupled de novo folding of human lysozyme, we have constructed 23 mutant enzymes in which cysteine residue(s) were replaced by alanine(s). the mutant genes were translated in vitro in a system composed of rabbit reticulocyte lysate, canine pancreatic microsomal vesicles and oxidized glutathione. this system allows the formation of intramolecular disulfide bonds in translation products translocated into the microsomal lumen. the mobilities of the tra ... | 1991 | 2040307 |
| molecular mimicry in candida albicans. role of an integrin analogue in adhesion of the yeast to human endothelium. | hematogenous infection with the yeast candida albicans now occurs with increasing frequency in the neonate, the immunocompromised patient, and the hyperglycemic or hyperalimented host. yeast-phase c. albicans expresses a protein that is antigenically and structurally related to cd11b/cd18, a member of the beta 2 integrins and a well-characterized adhesin for mammalian neutrophils. both the neutrophil protein and its analogue in c. albicans have an identical affinity for the c3 ligand ic3b, and b ... | 1991 | 2040685 |
| identification of lanosterol 14 alpha-methyl demethylase in human tissues. | lanosterol 14 alpha-methyl demethylase was investigated in human tissues using a radio-hplc assay to detect the 4,4-dimethyl-5 alpha-cholesta-8, 14-dien-3 beta-ol (diene) metabolite. the sequence of events leading to the demethylated product in human liver microsomes involves the conversion of the diol to the aldehyde followed by diene formation. enzyme activity displayed a greater than 10 fold variation among the 9 liver samples studied. kinetic parameters were determined and shown to differ be ... | 1991 | 2043135 |
| one-sided action of amphotericin b on cholesterol-containing membranes is determined by its self-association in the medium. | the inducement of k+ permeability through membranes by the polyene antibiotic amphotericin b (amb) has been analyzed as a measure of the antibiotic activity. dose-response curves have been obtained with cholesterol- and ergosterol-containing egg yolk phosphatidylcholine large unilamellar vesicles (luvs), human erythrocytes, and saccharomyces cerevisiae cells. conductance changes induced by amb in sterol-containing planar bilayer membranes have also been studied. amb self-association in aqueous b ... | 1991 | 2043613 |
| cloning and in vivo expression of the human gart gene using yeast artificial chromosomes. | two yeast artificial chromosomes (yacs) were isolated each with a full-length copy of the human gene that encodes the trifunctional protein containing phosphoribosylglycinamide synthetase (gars), phosphoribosylglycinamide formyltransferase (gart) and phosphoribosylaminoimidazole synthetase (airs). the yacs were characterized by restriction mapping and by in situ hybridization of cosmid subclones containing the yac ends to human metaphase chromosomes. one of the yacs contains co-cloned non-contig ... | 1991 | 2050105 |
| characterization of a cdna encoding the 70-kda single-stranded dna-binding subunit of human replication protein a and the role of the protein in dna replication. | replication protein a (rp-a) is a three-subunit single-stranded dna-binding protein that has been isolated from human cells. rp-a is essential for sv40 dna replication and may also be important in genetic recombination. the sequence of a cdna encoding the 70-kda subunit of human rp-a is reported. the 616-amino acid predicted open reading frame of the human protein is 31% identical with the 621-amino acid open reading frame of the 70-kda subunit of rp-a from the yeast saccharomyces cerevisiae. bo ... | 1991 | 2050703 |
| isolation of a yeast artificial chromosome spanning the 8;21 translocation breakpoint t(8;21)(q22;q22.3) in acute myelogenous leukemia. | the 8;21 translocation is one of the most common specific rearrangements in acute myelogenous leukemia. we have identified markers (d21s65 and a not i boundary clone, not-42, referred to as probe b) flanking the chromosome 21 translocation breakpoint (21q22.3) that demonstrate physical linkage in normal genomic dna, by using at least three restriction endonucleases (not i, sac ii, and bsshii), and that are located not more than 250-280 kilobases apart. pulsed-field gel analysis of dna from somat ... | 1991 | 2052570 |
| source and role of diacylglycerol formed during phagocytosis of opsonized yeast particles and associated respiratory burst in human neutrophils. | the results presented in this paper demonstrate that in human neutrophils phagocytosis of c3b/bi and igg-opsonized yeast particles is associated with activation of phospholipase d and that this reaction is the main source of diglycerides. the demonstration is based upon the following findings: 1) the challenge of neutrophils with these opsonized particles was followed by a rapid formation of [3h]alkyl-phosphatidic acid [( 3h]alkyl-pa) and [3h]alkyl-diglyceride [( 3h]alkyl-dg) in cells labeled wi ... | 1991 | 2059222 |
| a region of proto-dbl essential for its transforming activity shows sequence similarity to a yeast cell cycle gene, cdc24, and the human breakpoint cluster gene, bcr. | proto-dbl is a human proto-oncogene, whose oncogenic activation was initially detected by dna transfection. we report significant sequence similarity between the predicted proto-dbl product and the products of cdc24, a saccharomyces cerevisiae cell division cycle gene required for correct budding and establishment of cell polarity, and bcr, a gene implicated in the pathogenesis of chronic myelogenous leukemia (cml). of 925 residues of the predicted proto-dbl protein, a stretch of 238 residues sh ... | 1991 | 2065022 |
| affinity purification of transcription factor iia from hela cell nuclear extracts. | one of the general transcription factors, tfiia, was purified to homogeneity from hela cell nuclear extracts by yeast tfiid affinity chromatography. human tfiia had a molecular weight of approximately 38 kd. it was able to associate with the complex formed by yeast tfiid and the tata elements of the adenovirus e4 and ml promoters, and the hsp70 promoter. the association extended the protected region on each tata element by yeast tfiid from dnase i digestion. affinity-purified tfiia was also able ... | 1991 | 2065666 |
| alu-primed polymerase chain reaction for regional assignment of 110 yeast artificial chromosome clones from the human x chromosome: identification of clones associated with a disease locus. | over 400 yeast artificial chromosome (yac) clones were isolated from the human x chromosome, and 110 of these were assigned to regions defined by chromosome translocation and deletion breakpoints. polymerase chain reaction using alu primers was applied to yac clones in order to generate probes, to identify overlapping clones, and to derive "fingerprints" and sequence data directly from total yeast dna. several clones were identified in regions of medical interest. one set of three overlapping cl ... | 1991 | 2068096 |
| furin is a subtilisin-like proprotein processing enzyme in higher eukaryotes. | the human fur gene encodes a protein, designated furin, the c-terminal half of which contains a transmembrane and a cysteine-rich receptor-like domain. the n-terminal half of furin exhibits striking primary amino acid sequence similarity to the catalytic domains of members of the subtilisin family of serine proteases. we here report characteristics of the furin protein and propose a three-dimensional model for its presumptive catalytic domain with characteristics, that predict furin to exhibit a ... | 1990 | 2094803 |