Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In Saccharomyces cerevisiae, the GTP-binding Ypt1 protein (Ypt1p) is essential for endoplasmic reticulum-to-Golgi protein transport. By exploiting a GAL10-YPT1 fusion to regulate YPT1 expression, three multicopy suppressors, SLY2, SLY12, and SLY41, and a single-copy suppressor, SLY1-20, that allowed YPT1-independent growth were isolated. Wild-type Sly1p is hydrophilic, is essential for cell viability, and differs from Sly1-20p by a single amino acid. SLY2 and SLY12 encode proteins with hydrophobic tails similar to synaptobrevins, integral membrane proteins of synaptic vesicles in higher eucaryotes. Sly41p is hydrophobic and exhibits sequence similarities with the chloroplast phosphate translocator. SLY12 but not SLY41 is an essential gene. The SLY2 null mutant is cold and heat sensitive. The SLY gene products may comprise elements of the protein transport machinery.
Mol Cell Biol 1991 Feb
PMID:Identification and structure of four yeast genes (SLY) that are able to suppress the functional loss of YPT1, a member of the RAS superfamily. 199 Feb 90

In this paper we have examined the effect of cold exposure on hepatic mitochondrial state 3 respiration and ATP synthesis, using succinate as the substrate, in euthyroid, hypothyroid and hyperthyroid rats. The results show that cold exposure does not elicit any variation in the above parameters in euthyroid and hyperthyroid rats, whereas when hypothyroid rats are exposed to cold, a significant increase (about +45%) occurs in state 3 respiration and ATP synthesis. We have also measured succinic dehydrogenase specific activity and uncoupled respiration during cold exposure in various thyroid states. The finding that cold exposure elicits no variation in the above parameters indicates that there is some control on ATP synthase and/or adenine nucleotide translocator. The above findings, as a whole, suggest that cold exposure acts on oxidative phosphorylation only if triiodothyronine is lacking, by controlling ATP synthase and/or adenine nucleotide translocator.
Mol Cell Endocrinol 1991 Jan
PMID:The effect of thyroid state and cold exposure on rat liver oxidative phosphorylation. 205 Feb 63

The presence of redox systems in microsomes of brown adipose tissue (BAT) in cold exposed rats was investigated and compared with liver. BAT microsomes showed high activity of lipid peroxidation measured both by the formation of malondialdehyde (MDA) and by oxygen uptake. NADH and NADPH dependent cytochrome c reductase activity were present in both BAT and liver microsomes. Aminopyrine demethylase and aniline hydroxylase activities, the characteristic detoxification enzymes in liver microsomes could not be detected in BAT microsomes. BAT minces showed very poor incorporation of [1-14C]acetate and [2-14C]mevalonate in unsaponifiable lipid fraction compared to liver. Biosynthesis of cholesterol and ubiquinone, but not fatty acids, and the activity of 3-hydroxy-3-methyl glutaryl CoA reductase appear to be very low in BAT. Examination of difference spectra showed the presence of only cytochrome b5 in BAT microsomes. In addition to the inability to detect the enzyme activities dependent on cytochrome P-450, a protein with the characteristic spectrum, molecular size in SDS-PAGE and interaction with antibodies in double diffusion test, also could not be detected in BAT microsomes. The high activity of lipid peroxidation in microsomes, being associated with large oxygen uptake and oxidation of NADPH, will also contribute to the energy dissipation as heat in BAT, considered important in thermogenesis.
Mol Cell Biochem 1990 Feb 09
PMID:Microsomal redox systems in brown adipose tissue: high lipid peroxidation, low cholesterol biosynthesis and no detectable cytochrome P-450. 210 21

We have analyzed the effect of the poly(ADP-ribose) synthesis inhibitor 3 aminobenzamide (3AB) on de novo and methyl methanesulfonate (MMS) and gamma irradiation enhancement of viral transformation of a cloned rat embryo fibroblast cell line, CREF, by a cold-sensitive host-range mutant of type 5 adenovirus, H5hr1. Additionally, we have evaluated the effect of 3AB on the transformation of CREF cells following transfection with a gene conferring resistance to hygromycin (hygr) or the neomycin analogue G418 (neor) in combination with a cloned type 5 adenovirus E1A transforming gene (Ad5 E1A) or the Ha-ras (T24) oncogene. 3AB induced a dose- and time-dependent increase in the level of de novo MMS-enhanced and gamma irradiation-enhanced transformation of CREF cells by H5hr1, whereas it did not induce morphological transformation in uninfected control, MMS-pretreated, or gamma irradiation-pretreated CREF cells. Temporal kinetic studies indicated that 3AB was most effective in enhancing de novo and MMS-enhanced and gamma irradiation-enhanced viral transformation when applied early after viral and carcinogen plus viral infection and when present for extended time periods (4-5 wk). 3AB also increased the frequency of resistant colonies following transfection with several cloned genes, including hygr, neor, and protein kinase C (which also contained a neor gene), and the frequency of morphological transformation of CREF cells following cotransfection with a hygr gene and an Ad5 E1A or an activated Ha-ras (T24) gene. In contrast, 3AB exerted the opposite effect, i.e., an inhibitory effect, when applied to NIH 3T3 cells transfected with a hygr or neor gene, alone or in combination with a T24 gene. The ability of 3AB to enhance the frequency of transformation of CREF cells was not associated with a selective effect on the growth of H5hr1-transformed CREF cells in monolayer or agar culture. Similarly, 3AB did not alter the percentage of MMS- or gamma irradiated-pretreated H5hr1-infected cells retaining free Ad5 DNA or the random pattern or quantity of viral DNA integration in control or carcinogen-treated H5hr1-transformed cells. These results suggest that cellular processes regulated by the nuclear enzyme ADPRT, or additional processes modified by 3AB, may be important mediators of stable transformation induced by transfected DNA and both de novo and carcinogen-enhanced viral transformation of specific target cells.
Mol Carcinog 1990
PMID:Enhancement of viral and DNA mediated transformation of cloned rat embryo fibroblast cells by 3-aminobenzamide. 212 9

ADP ribosylation factor (ARF) is a ubiquitous 21-kDa GTP-binding protein in eucaryotes. ARF was first identified in animal cells as the protein factor required for the efficient ADP-ribosylation of the mammalian G protein Gs by cholera toxin in vitro. A gene (ARF1) encoding a protein homologous to mammalian ARF was recently cloned from Saccharomyces cerevisiae (Sewell and Kahn, Proc. Natl. Acad. Sci. USA, 85:4620-4624, 1988). We have found a second gene encoding ARF in S. cerevisiae, ARF2. The two ARF genes are within 28 centimorgans of each other on chromosome IV, and the proteins encoded by them are 96% identical. Disruption of ARF1 causes slow growth, cold sensitivity, and sensitivity to normally sublethal concentrations of fluoride ion in the medium. Disruption of ARF2 causes no detectable phenotype. Disruption of both genes is lethal; thus, ARF is essential for mitotic growth. The ARF1 and ARF2 proteins are functionally homologous, and the phenotypic differences between mutations in the two genes can be accounted for by the level of expression; ARF1 produces approximately 90% of total ARF. Among revertants of the fluoride sensitivity of an arf1 null mutation were ARF1-ARF2 fusion genes created by a gene conversion event in which the deleted ARF1 sequences were repaired by recombination with ARF2.
Mol Cell Biol 1990 Dec
PMID:ADP ribosylation factor is an essential protein in Saccharomyces cerevisiae and is encoded by two genes. 212 95

DNA preparations obtained from 122 species of fishes, 5 species of amphibians, and 13 species of reptiles were investigated in their compositional properties by analytical equilibrium centrifugation in CsCl density gradients. These species represented 21 orders of Osteichthyes, 3 orders of Chondrichthyes, 2 orders of amphibians, and 3 orders of reptiles. Modal buoyant densities of fish DNAs ranged from 1.696 to 1.707 g/cm3, the vast majority of values falling, however, between 1.699 and 1.704 g/cm3, which is the range covered by the DNAs of amphibians and reptiles. In all cases, DNA bands in CsCl were only weakly asymmetrical and only very rarely were accompanied by separate satellite bands (mostly on the GC-rich side). Intermolecular compositional heterogeneities were low in the vast majority of cases, and, like CsCl band asymmetries, at least partially due to cryptic or poorly resolved satellites. The present findings indicate, therefore, that DNAs from cold-blooded vertebrates are characterized by a number of common properties, namely a very wide spectrum of modal buoyant densities, low intermolecular compositional heterogeneities, low CsCl band asymmetries, and, in most cases, small amounts of satellite DNAs. In the case of fish DNAs a negative correlation was found between the GC level and the haploid size (c value) of the genome. If polyploidization is neglected, this phenomenon appears to be mainly due to the fact that increases and decreases in GC are associated with contraction and expansion phenomena, respectively, of intergenic noncoding sequences, which are GC poor relative to coding sequences.
J Mol Evol 1990 Oct
PMID:Compositional patterns in the nuclear genome of cold-blooded vertebrates. 212 75

The compositional properties of DNAs from 122 species of fishes and from 18 other cold-blooded vertebrates (amphibians and reptiles) were compared with those from 10 warm-blooded vertebrates (mammals and birds) and found to be substantially different. Indeed, DNAs from cold-blooded vertebrates are characterized by much lower intermolecular compositional heterogeneities and CsCl band asymmetries, by a much wider spectrum of modal buoyant densities in CsCl, by generally lower amounts of satellites, as well as by the fact that in no case do buoyant densities reach the high values found in the GC-richest components of DNAs from warm-blooded vertebrates. In the case of fish genomes, which were more extensively studied, different orders were generally characterized by modal buoyant densities that were different in average values as well as in their ranges. In contrast, different families within any given order were more often characterized by narrow ranges of modal buoyant densities, and no difference in modal buoyant density was found within any single genus (except for the genus Aphyosemion, which should be split into several genera). The compositional differences that were found among species belonging to different orders and to different families within the same order are indicative of compositional transitions, which were shown to be essentially due to directional base substitutions. These transitions were found to be independent of geological time. Moreover, the rates of directional base substitutions were found to be very variable and to reach, in some cases, extremely high values, that were even higher than those of silent substitutions in primates. The taxonomic and evolutionary implications of these findings are discussed.
J Mol Evol 1990 Oct
PMID:Compositional transitions in the nuclear genomes of cold-blooded vertebrates. 212 76

The influence of rat round spermatid protein(s) (RSP) on protein synthesis and secretory function of Sertoli cells was used in the bicameral chamber system. Round spermatids (RS) were purified from 90-day-old rats by centrifugal elutriation. RS were incubated in a supplement-enriched culture medium that lacked exogenous proteins. The RS-conditioned media were dialysed and lyophilized to obtain RSP. Most de novo protein synthesized under basal conditions by Sertoli cells (18-day-old) was secreted into the apical chamber (apical/basal ratio: 3.42). Follicle-stimulating hormone (FSH, 100 ng/ml) stimulated total protein secretion from Sertoli cells by a factor of 1.54. The RSP (100 micrograms/ml) stimulated total protein secretion from Sertoli cells by a factor of 2.33. The enhancement of total Sertoli cell protein secretion by FSH and RSP additively increased by a factor of 2.82. The combined effect of FSH and RSP on total protein secretion from Sertoli cells was dose dependent and saturated at approximately 200 micrograms/ml of RSP. Polarity of total protein secretion from Sertoli cells (apical/basal ratio: 3.42) was stimulated by RSP predominantly in the apical direction (apical/basal ratio: 8.48). The modulation of radiolabeled Sertoli cell secretory proteins (ceruloplasmin, CP; sulfated glycoprotein-2, SGP-2; testins and transferrin, Tf) by cold (non-labeled) RSP was investigated by immunoprecipitation followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The secretion of CP, SGP-2 and Tf was stimulated in a dose-dependent manner by the addition of RSP up to a saturating concentration of between 200 and 300 micrograms/ml, whereas the secretion of Sertoli cell testins did not reach saturation at 300 micrograms/ml RSP. These results indicate that FSH and RSP independently modulate Sertoli cell protein secretion, and that Sertoli cell secretory proteins may differentially respond to RSP stimulation.
Mol Cell Endocrinol 1990 Oct 01
PMID:Modulation of Sertoli cell secretory function by rat round spermatid protein(s). 212 59

We have analyzed the effect of gamma irradiation on the induction of morphological transformation of cloned rat embryo fibroblast (CREF) cells by the host-range cold-sensitive type 5 adenovirus mutant, H5hr1. Treatment of CREF cells with 1-6 Gy of gamma irradiation immediately prior to viral infection resulted in dose-dependent decrease in cell survival and concomitant increase in viral transformation frequency. Exposure of CREF cells to 1-6 Gy of gamma radiation alone resulted in a similar dose-dependent inhibition in cell survival but without any subsequent morphological transformation. The effect of gamma irradiation on viral transformation was greatest when cells were irradiated directly before viral infection. The reduction in the enhancement of transformation was both dose and time dependent. The ability of gamma irradiation to enhance viral transformation was substantially reduced if CREF cells were treated with inhibitors of RNA (actinomycin D) and protein (cycloheximide) synthesis. Employing a single-cell colony transfer assay and in situ hybridization with a 32P-labeled Ad5 DNA probe, we found that gamma irradiation of CREF cells prior to infection with H5hr1 resulted, 10 and 17 d after infection and replating, in an increase in the percentage of surviving CREF colonies that contain Ad5 DNA. Analysis of viral DNA integration by DNA-filter hybridization (Southern blot analysis) in H5hr1-transformed CREF clones isolated from untreated and gamma-irradiated cultures indicates that gamma irradiation caused increases in both the number of copies of Ad5 E1A DNA sequences integrated into cellular DNA and the number of unique Ad5 E1A DNA integration sites in transformed cells. These results indicate that gamma irradiation enhancement of adenovirus transformation was a consequence of radiation-induced cellular factors with finite life spans that are mediators of enhanced viral transformation. Potentially important components of the radiation enhancement process appear to involve an alteration in both the retention of free Ad5 DNA in surviving cells and an alteration in the profile of viral-DNA integration in gamma-irradiated cells.
Mol Carcinog 1990
PMID:Enhancement of adenovirus transformation of cloned rat embryo fibroblast cells by gamma irradiation. 214 98

This report describes the first isolation and molecular characterization of the mitochondrial F1-ATPase from Trypanosoma brucei. The isolation procedure utilized is a modified chloroform extraction procedure. In contrast to earlier reports on the F1-ATPase from other trypanosomatids, the F1-ATPase we have isolated from the procyclic form of T. brucei a complex composed of five distinct subunits. Apparent molecular weights of these subunits are 55,000 [alpha], 42,000 [beta], 32,000 [gamma], 22,000 [delta], and 17,000 [epsilon]. The F1 moiety which possesses the active site of the H(+)-ATPase has an ATPase activity in the standard Tris-HCl coupled enzyme assay with a Vmax of 22.96 mumol min-1 (mg protein)-1 and a Km value of 0.60 mM. This ATPase activity is cold labile and is not susceptible to oligomycin inhibition as is the membrane bound enzyme. Upon reconstitution with F1-ATPase depleted membranes (urea particles) the ATPase regains oligomycin sensitivity to the same extent as that found in the intact inner membrane vesicles. ATP synthesis is also restored to these particles upon reconstitution with F1. These results indicate that this F1-ATPase as isolated is intact with respect to all the critical H(+)-ATPase functions.
Mol Biochem Parasitol 1990 Nov
PMID:The mitochondrial ATP synthase of Trypanosoma brucei: isolation and characterization of the intact F1 moiety. 214 43


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