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 contrast to the Escherichia coli lac operon, the yeast beta-galactosidase gene is positively regulated. In the 5'-noncoding region of the Kluyveromyces lactis LAC4 gene, we mapped an upstream activation site (UAS) that is required for induction. This sequence, located between positions -435 and -326 from the start of translation, functions irrespective of its orientation and can confer lactose regulation to the heterologous CYC1 promoter. It is composed of at least two subsequences that must act in concert. One of these subsequences showed a strong homology to the UAS consensus sequence of the Saccharomyces cerevisiae GAL genes (E. Giniger, S. M. Varnum, and M. Ptashne, Cell 40:767-774, 1985). We propose that this region of homology located at about position -426 is a binding site for the product of the regulatory gene LAC9 which probably induces transcription of the LAC4 gene in a manner analogous to that of the GAL4 protein.
Mol Cell Biol 1987 Mar
PMID:Positive regulation of the beta-galactosidase gene from Kluyveromyces lactis is mediated by an upstream activation site that shows homology to the GAL upstream activation site of Saccharomyces cerevisiae. 310 72

The biosynthesis and biochemical characteristics of the 39,000 cell surface glycoprotein detected by Mab 41H.16 were investigated. Experiments utilizing tunicamycin, endoglycosidase H, endoglycosidase F and N-glycosidase F indicate that the mature molecule expressed at the cell surface is composed largely of N-linked oligosaccharides of both the complex and high mannose types. When synthesized in the presence of tunicamycin, the molecule appeared on the cell surface with a Mr of 32,000. Digestion with both endoglycosidase H and endoglycosidase F yielded a single band of Mr 37,000. Parallel experiments with N-glycosidase F revealed species of approx. 35,000 and 32,000. Synthesis in the presence of monensin yielded a 37,500 product. [3H]Glucosamine and [3H]mannose were incorporated into the molecule but no evidence for fucose incorporation could be found. Microheterogeneity of gp39 with respect to Mr and oligosaccharide structure was demonstrated by biosynthetic labelling and lectin chromatography. Biosynthetic pulse-chase labelling showed that the de novo synthesis of the 39,000 molecule occurs without detectable precursor formation. Results of temperature-dependent phase separation experiments were consistent with gp39 being an integral membrane protein. Two-dimensional electrophoresis showed heterogeneity of the isoelectric points associated with the N-linked oligosaccharides. Galactose oxidase/NaB[3H]4 labelling showed that a terminal sialic acid protects a galactose residue. All results are consistent with the conclusion that the gp39 molecule is an integral membrane glycoprotein composed of heterogeneous N-linked oligosaccharides of both the complex and high mannose types.
Mol Immunol 1988 Sep
PMID:Characterization of gp39, a B-lymphocyte associated differentiation antigen which is also present on granulocytes and macrophages. 326 83

Transcription directed into a Saccharomyces cerevisiae autonomously replicating sequence (ARS) causes high-frequency loss of minichromosomes. Conditionally stable artificial yeast chromosomes were constructed that contain an inducible GAL promoter upstream of ARS1. Under growth conditions in which the promoter was inactive, these chromosomes were mitotically stable; however, when the GAL promoter was induced, the chromosomes became extremely unstable as a result of transcriptional impairment of ARS function. This interference by the GAL promoter occurred only in cis but can occur from either side of ARS1. Transcriptional interference of ARS function can be monitored readily by using a visual colony-color assay (P. Hieter, C. Mann, M. Snyder, and R.W. Davis, Cell 40:381-392, 1985), which was further developed as a sensitive in vivo assay for sequences which rescue ARS from transcription. DNA fragments from the 3' ends of genes, inserted downstream of the GAL promoter, protected ARS function from transcriptional interference. This assay is expected to be independent of both RNA transcript stability and processing. Philippsen et al. have shown that transcription into a yeast centromere inhibits CEN function in vivo (L. Panzeri, I. Groth-Clausen, J. Shepard, A. Stotz, and P. Philippsen, Chromosomes Today 8:46-58, 1984). We identified two 200- to 300-base-pair DNA fragments flanking CEN4 that rescued ARS1 from transcription. Both of these fragments protected ARS from transcription when inserted in either orientation. The 3' ends of stable transcripts are encoded by fragments that protected the ARS from transcription, suggesting that the protection was achieved by transcription termination. It is suggested that protection of elements important for the replication and segregation of eucaryotic chromosomes from transcription is necessary for their proper function in vivo.
Mol Cell Biol 1988 May
PMID:Transcription interferes with elements important for chromosome maintenance in Saccharomyces cerevisiae. 329 Jun 52

High levels of the GAL7 gene in the yeast cell appear to titrate regulatory factors and to impair transcription of related sequences. To investigate the role that the GAL regulatory factors GAL4 and GAL80 have in this process we have compared the accumulation of mRNA transcribed from single-copy (plasmid-borne GAL7 and chromosomal GAL10) and high-copy (plasmid-borne GAL7) genes in several GAL regulatory mutants. Our results show that functional GAL4 gene product is required for induction of transcription from the single- and high-copy genes. In a strain containing the GAL4 gene fused to the high expression ADH1 promoter, glucose can replace galactose to induce high levels of transcription of GAL7 and GAL10 genes, although the kinetics of accumulation induced by the two sugars are distinctly different. In the presence of high levels of GAL4, maximum accumulation of mRNA from single and high copy genes is elevated two-fold; disruption of the gal80 gene in combination with high levels of GAL4 results in a further two-fold increase in transcription. In this genetic background, galactose-induced transcription of the high copy GAL7 gene results in a greater than 50-fold increase in the levels of GAL7 mRNA, representing 30%-50% of the total cellular mRNA. Our results are consistent with a cooperative effect of saturation of multiple GAL4 DNA binding sites and with a limiting factor, in addition to GAL4, that is required for transcription of the GAL genes.
Mol Gen Genet 1987 Jun
PMID:Transcription of multiple copies of the yeast GAL7 gene is limited by specific factors in addition to GAL4. 330 4

The carbohydrate moiety of the Tc-85 surface glycoprotein from the infective trypomastigote form of Trypanosoma cruzi was analysed. Tc-85 could be metabolically labeled by incubation of the cells with D-[14C]mannose or D-[14C]glucose. Degradation techniques were performed directly on the polyacrylamide gel band containing labeled Tc-85. A mannobiose was cleaved by beta-elimination and further treatment of the remaining material under conditions which liberate N-asparaginyl linkages, released a complex oligosaccharide. The presence of sialic acid was demonstrated by: mild acid hydrolysis, neuraminidase treatment and periodate oxidation under mild conditions followed by NaB3H4 reduction, hydrolysis, and detection of NANA7 by paper electrophoresis. In addition, the chromatographic behavior of the asialooligosaccharide was significantly different from that of the original sample. Galactose, mannose and glucosamine are the other monosaccharide components of the sialooligosaccharide.
Mol Biochem Parasitol 1987 Nov
PMID:Sialic acid in a complex oligosaccharide chain of the Tc-85 surface glycoprotein from the trypomastigote stage of Trypanosoma cruzi. 332 4

In rat pancreatic islets, the apparent space of distribution of galactose is not different from that of other hexoses. In homogenates of islets or tumoral insulin-producing cells, galactose is phosphorylated at a very low rate relative to either glucose phosphorylation in the same tissues or galactose phosphorylation by liver homogenates. In intact islets, galactose increases modestly the glucose 6-phosphate content and is oxidized at a much lower rate than glucose. Galactose slightly increases insulin output in the presence of a stimulatory concentration of glucose but fails to provoke insulin release in the absence of glucose, whether in islets removed from rats fed a normal or galactose-rich diet. The low rate of galactose oxidation and its poor insulinotropic capacity appear attributable to the weak activity of galactokinase in pancreatic islets.
Mol Cell Biochem 1985 Feb
PMID:Hexose metabolism in pancreatic islets. Galactose transport, phosphorylation and oxidation. 388 1

Five DNase I-hypersensitive regions were associated with the Saccharomyces cerevisiae galactose gene cluster during both galactose induction and glucose repression of transcription. Four hypersensitive regions were located in areas flanking the GAL cluster genes, and one site occurred within GAL10. A DNase I-hypersensitive region located between the 5' ends of divergently transcribed GAL10 and GAL1 contained sequences essential for the transcription of both genes.
Mol Cell Biol 1985 Jun
PMID:DNase I-hypersensitive sites in the galactose gene cluster of Saccharomyces cerevisiae. 389 38

The galactose analogue 2-deoxygalactose was found to inhibit the growth of a mutant strain of Saccharomyces cerevisiae constitutively producing the set of galactose utilization enzymes. Based on this fact, the yeast GAL80 gene negatively regulating the expression of the genes encoding those enzymes was isolated for its ability to confer 2-deoxygalactose resistance on a strain carrying a recessive mutation in that gene. The GAL80 gene was located within a 3.0 kb fragment in the cloned DNA. When the isolated gene was incorporated into a multi-copy plasmid, the induced level of three enzymes encoded by the gene cluster GAL7-GAL10-GAL1 in the host chromosome was lowered. Such a gene dosage effect of GAL80 was further pronounced if sucrose, a sugar causing catabolite repression, was added to the growth medium. The ratio of the enzyme activity of the yeast bearing multiple copies of GAL80 to that of the yeast bearing its single copy significantly varied with the enzyme. From these results we suggest that the intracellular inducer interacts with the GAL80 product and that GAL80 molecules directly bind the GAL cluster genes with an affinity different from one gene to another.
Mol Gen Genet 1984
PMID:Regulation of expression of the galactose gene cluster in Saccharomyces cerevisiae. II. The isolation and dosage effect of the regulatory gene GAL80. 609 55

The GAL1 and GAL10 genes of Saccharomyces cerevisiae are divergently transcribed, with 606 base pairs of DNA separating their transcription initiation sites. These two genes are stringently coregulated: their expression is induced ca. 1,000-fold in cells growing on galactose and is repressed by growth on glucose. The nucleotide sequence of the region of DNA between these genes and the precise sites of transcription initiation are presented here. The most notable feature of the nucleotide sequence of this region is a 108-base-pair guanine-plus-cytosine-rich stretch of DNA located approximately in the middle of the region between GAL1 and GAL10. Analysis of the effects of mutations that alter the region between these two genes, constructed in vitro or selected in vivo, suggest that these guanine-plus-cytosine-rich sequences are required for the expression of both genes. The region of DNA between GAL1 and GAL10 is sufficient for regulation of expression of these genes: fusion of the region to the yeast HIS3 gene places HIS3 under GAL control.
Mol Cell Biol 1984 Aug
PMID:Sequences that regulate the divergent GAL1-GAL10 promoter in Saccharomyces cerevisiae. 609 12

In Saccharomyces cerevisiae, the transcriptional expression of the galactose-melibiose catabolic pathway genes is under the control of at least three regulatory genes, GAL4, GAL80, and GAL3. We have isolated the GAL80 gene and have studied the effect of a null mutation on the carbon-controlled regulation of the MEL1 and GAL cluster genes. The null mutation was achieved in vivo by replacing the chromosomal wild-type GAL80 allele with an in vitro-created GAL80 deletion-disruption mutation. Enzyme activities and RNA levels for the GAL cluster and MEL1 genes were constitutively expressed in the null mutant strain grown on glycerol-lactate and were higher than in the isogenic wild-type yeast strain when compared after growth on galactose. Carbon catabolite repression of the GAL cluster and MEL1 genes, which occurs at the level of transcription, is retained in the null mutant. Deletion of the GAL80 gene in a gal4 cell does not restore GAL cluster and MEL1 gene expression. The data demonstrate that (i) the GAL80 protein is a purely negative regulator, (ii) the GAL80 protein does not mediate carbon catabolite repression, and (iii) the GAL4 protein is not simply an antagonizer of GAL80-mediated repression.
Mol Cell Biol 1984 Aug
PMID:Disruption of regulatory gene GAL80 in Saccharomyces cerevisiae: effects on carbon-controlled regulation of the galactose/melibiose pathway genes. 609 16


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