Gal3p and Gal1p interact with the transcriptional repressor Gal80p to form a complex of 1:1 stoichiometry

2002 ◽  
Vol 363 (3) ◽  
pp. 515-520 ◽  
Author(s):  
David J. TIMSON ◽  
Helen C. ROSS ◽  
Richard J. REECE
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Gel Filtration ◽  
Transcriptional Repressor ◽  
Galactose Metabolism ◽  
Genetic Switch ◽  
Sequence Identity ◽  
Genes Encoding ◽  
Small Molecule Ligands ◽  
High Degree

The genes encoding the enzymes required for galactose metabolism in Saccharomyces cerevisiae are controlled at the level of transcription by a genetic switch consisting of three proteins: a transcriptional activator, Gal4p; a transcriptional repressor, Gal80p; and a ligand sensor, Gal3p. The switch is turned on in the presence of two small molecule ligands, galactose and ATP. Gal3p shows a high degree of sequence identity with Gal1p, the yeast galactokinase. We have mapped the interaction between Gal80p and Gal3p, which only occurs in the presence of both ligands, using protease protection experiments and have shown that this involves amino acid residue 331 of Gal80p. Gel-filtration experiments indicate that Gal3p, or the galactokinase Gal1p, interact directly with Gal80p to form a complex with 1:1 stoichiometry.

Multiple GCD genes required for repression of GCN4, a transcriptional activator of amino acid biosynthetic genes in Saccharomyces cerevisiae

1986 ◽  
Vol 6 (11) ◽  
pp. 3990-3998
Author(s):  
S Harashima ◽  
A G Hinnebusch
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid ◽  
Lacz Gene ◽  
Gene Products ◽  
Wild Type ◽  
Double Mutation ◽  
Double Stranded Rna ◽  
Amino Acid Availability ◽  
Genes Encoding ◽  
New Alleles

GCN4 encodes a positive regulator of multiple unlinked genes encoding amino acid biosynthetic enzymes in Saccharomyces cerevisiae. Expression of GCN4 is coupled to amino acid availability by a control mechanism involving GCD1 as a negative effector and GCN1, GCN2, and GCN3 as positive effectors of GCN4 expression. We used reversion of a gcn2 gcn3 double mutation to isolate new alleles of GCD1 and mutations in four additional GCD genes which we designate GCD10, GCD11, GCD12, and GCD13. All of the mutations lead to constitutive derepression of HIS4 transcription in the absence of the GCN2+ and GCN3+ alleles. By contrast, the gcd mutations require the wild-type GCN4 allele for their derepressing effect, suggesting that each acts by influencing the level of GCN4 activity in the cell. Consistent with this interpretation, mutations in each GCD gene lead to constitutive derepression of a GCN4::lacZ gene fusion. Thus, at least five gene products are required to maintain the normal repressed level of GCN4 expression in nonstarvation conditions. Interestingly, the gcd mutations are pleiotropic and also affect growth rate in nonstarvation conditions. In addition, certain alleles lead to a loss of M double-stranded RNA required for the killer phenotype. This pleiotropy suggests that the GCD gene products contribute to an essential cellular function, in addition to, or in conjunction with, their role in GCN4 regulation.

scholarly journals Purification and Characterization of Catalase from Marine BacteriumAcinetobactersp. YS0810

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Xinhua Fu ◽  
Wei Wang ◽  
Jianhua Hao ◽  
Xianglin Zhu ◽  
Mi Sun
Keyword(s):  
Amino Acid ◽  
Ion Exchange ◽  
Gel Filtration ◽  
Protoporphyrin Ix ◽  
Hydroxylamine Hydrochloride ◽  
Sodium Dithionite ◽  
Flight Mass Spectrometry ◽  
Alkali Stability ◽  
High Alkali ◽  
High Degree

The catalase from marine bacteriumAcinetobactersp. YS0810 (YS0810CAT) was purified and characterized. Consecutive steps were used to achieve the purified enzyme as follows: ethanol precipitation, DEAE Sepharose ion exchange, Superdex 200 gel filtration, and Resource Q ion exchange. The active enzyme consisted of four identical subunits of 57.256 kDa. It showed a Soret peak at 405 nm, indicating the presence of iron protoporphyrin IX. The catalase was not apparently reduced by sodium dithionite but was inhibited by 3-amino-1,2,4-triazole, hydroxylamine hydrochloride, and sodium azide. Peroxidase-like activity was not found with the substrate o-phenylenediamine. So the catalase was determined to be a monofunctional catalase. N-terminal amino acid of the catalase analysis gave the sequence SQDPKKCPVTHLTTE, which showed high degree of homology with those of known catalases from bacteria. The analysis of amino acid sequence of the purified catalase by matrix-assisted laser desorption ionization time-of-flight mass spectrometry showed that it was a new catalase, in spite of its high homology with those of known catalases from other bacteria. The catalase showed high alkali stability and thermostability.

scholarly journals Localization and Interaction of the Proteins Constituting the GAL Genetic Switch in Saccharomyces cerevisiae

2008 ◽  
Vol 7 (12) ◽  
pp. 2061-2068 ◽  
Author(s):  
Raymond Wightman ◽  
Rachel Bell ◽  
Richard J. Reece
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Cellular Localization ◽  
Transcriptional Control ◽  
Resonance Energy ◽  
Regulatory Proteins ◽  
Yeast Cells ◽  
Galactose Metabolism ◽  
Genetic Switch ◽  
Metabolism Regulation

ABSTRACT In Saccharomyces cerevisiae, the GAL genes encode the enzymes required for galactose metabolism. Regulation of these genes has served as the paradigm for eukaryotic transcriptional control over the last 50 years. The switch between inert and active gene expression is dependent upon three proteins—the transcriptional activator Gal4p, the inhibitor Gal80p, and the ligand sensor Gal3p. Here, we present a detailed spatial analysis of the three GAL regulatory proteins produced from their native genomic loci. Using a novel application of photobleaching, we demonstrate, for the first time, that the Gal3p ligand sensor enters the nucleus of yeast cells in the presence of galactose. Additionally, using Förster resonance energy transfer, we show that the interaction between Gal3p and Gal80p occurs throughout the yeast cell. Taken together, these data challenge existing models for the cellular localization of the regulatory proteins during the induction of GAL gene expression by galactose and suggest a mechanism for the induction of the GAL genes in which galactose-bound Gal3p moves from the cytoplasm to the nucleus to interact with the transcriptional inhibitor Gal80p.

The Saccharomyces cerevisiae CKS1 gene, a homolog of the Schizosaccharomyces pombe suc1+ gene, encodes a subunit of the Cdc28 protein kinase complex

1989 ◽  
Vol 9 (5) ◽  
pp. 2034-2041
Author(s):  
J A Hadwiger ◽  
C Wittenberg ◽  
M D Mendenhall ◽  
S I Reed
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Schizosaccharomyces Pombe ◽  
Temperature Sensitive ◽  
G1 Arrest ◽  
Genes Encoding ◽  
A Subunit ◽  
Identity Disruption ◽  
High Degree ◽  
High Copy Plasmid

The Saccharomyces cerevisiae gene CDC28 encodes a protein kinase required for cell cycle initiation. In an attempt to identify genes encoding proteins that interact with the Cdc28 protein kinase, high-copy plasmid suppressors of a temperature-sensitive cdc28 mutation were isolated. One such suppressor, CKS1, was found to encode an 18-kilodalton protein that shared a high degree of homology with the suc1+ protein (p13) of Schizosaccharomyces pombe (67% amino acid sequence identity). Disruption of the chromosomal CKS1 gene conferred a G1 arrest phenotype similar to that of cdc28 mutants. The presence of the 18-kilodalton Cks1 protein in yeast lysates was demonstrated by using Cks-1 specific antiserum. Furthermore, the Cks1 protein was shown to be physically associated with active forms of the Cdc28 protein kinase. These data suggest that Cks1 is an essential component of the Cdc28 protein kinase complex.

scholarly journals Temporal analysis of general control of amino acid biosynthesis in Saccharomyces cerevisiae: role of positive regulatory genes in initiation and maintenance of mRNA derepression.

1984 ◽  
Vol 4 (3) ◽  
pp. 520-528 ◽  
Author(s):  
M D Penn ◽  
G Thireos ◽  
H Greer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Steady State ◽  
Amino Acid ◽  
Gene Product ◽  
Temporal Analysis ◽  
Regulatory Genes ◽  
Single Amino Acid ◽  
Mrna Levels ◽  
Initiation Phase ◽  
Genes Encoding

In Saccharomyces cerevisiae, starvation for a single amino acid results in the derepression of enzyme activities in multiple amino acid biosynthetic pathways. Derepression is a consequence of increased transcription of the genes encoding these enzymes. Analysis of the kinetics of mRNA elevation established that derepression occurs within 5 min of a shift of the culture from rich medium to starvation medium. Any starvation condition was sufficient to trigger an initial high mRNA elevation; however, it was the severity of starvation which determined the steady-state mRNA levels that were subsequently established. The products of the positive regulatory genes AAS101, AAS103, and AAS2 were shown to be required in the initiation phase of this response, whereas the AAS102 gene product was required to maintain the new elevated steady-state mRNA levels. The AAS101 and AAS102 genes were cloned. Consistent with their respective roles in initiation and maintenance of derepression. AAS101 mRNA was found to be expressed at high levels in both rich and starvation media, whereas AAS102 mRNA was derepressed only under starvation conditions. The derepression of AAS102 mRNA is dependent on the AAS101 gene product.

scholarly journals The Saccharomyces cerevisiae CKS1 gene, a homolog of the Schizosaccharomyces pombe suc1+ gene, encodes a subunit of the Cdc28 protein kinase complex.

1989 ◽  
Vol 9 (5) ◽  
pp. 2034-2041 ◽  
Author(s):  
J A Hadwiger ◽  
C Wittenberg ◽  
M D Mendenhall ◽  
S I Reed
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Schizosaccharomyces Pombe ◽  
Temperature Sensitive ◽  
G1 Arrest ◽  
Genes Encoding ◽  
A Subunit ◽  
Identity Disruption ◽  
High Degree ◽  
High Copy Plasmid

The Saccharomyces cerevisiae gene CDC28 encodes a protein kinase required for cell cycle initiation. In an attempt to identify genes encoding proteins that interact with the Cdc28 protein kinase, high-copy plasmid suppressors of a temperature-sensitive cdc28 mutation were isolated. One such suppressor, CKS1, was found to encode an 18-kilodalton protein that shared a high degree of homology with the suc1+ protein (p13) of Schizosaccharomyces pombe (67% amino acid sequence identity). Disruption of the chromosomal CKS1 gene conferred a G1 arrest phenotype similar to that of cdc28 mutants. The presence of the 18-kilodalton Cks1 protein in yeast lysates was demonstrated by using Cks-1 specific antiserum. Furthermore, the Cks1 protein was shown to be physically associated with active forms of the Cdc28 protein kinase. These data suggest that Cks1 is an essential component of the Cdc28 protein kinase complex.

Ribosomal protein S14 is encoded by a pair of highly conserved, adjacent genes on the X chromosome of Drosophila melanogaster

1988 ◽  
Vol 8 (10) ◽  
pp. 4314-4321
Author(s):  
S J Brown ◽  
D D Rhoads ◽  
M J Stewart ◽  
B Van Slyke ◽  
I T Chen ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Drosophila Melanogaster ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Ribosomal Protein ◽  
X Chromosome ◽  
Duplicated Genes ◽  
Ribosomal Protein Genes ◽  
Yeast Saccharomyces Cerevisiae ◽  
Genes Encoding

We describe a Drosophila DNA clone of tandemly duplicated genes encoding an amino acid sequence nearly identical to human ribosomal protein S14 and yeast rp59. Despite their remarkably similar exons, the locations and sizes of introns differ radically among the Drosophila, human, and yeast (Saccharomyces cerevisiae) ribosomal protein genes. Transcripts of both Drosophila RPS14 genes were detected in embryonic and adult tissues and are the same length as mammalian S14 message. Drosophila RPS14 was mapped to region 7C5-9 on the X chromosome. This interval also encodes a previously characterized Minute locus, M(1)7C.

Temporal analysis of general control of amino acid biosynthesis in Saccharomyces cerevisiae: role of positive regulatory genes in initiation and maintenance of mRNA derepression

1984 ◽  
Vol 4 (3) ◽  
pp. 520-528
Author(s):  
M D Penn ◽  
G Thireos ◽  
H Greer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Steady State ◽  
Amino Acid ◽  
Gene Product ◽  
Temporal Analysis ◽  
Regulatory Genes ◽  
Single Amino Acid ◽  
Mrna Levels ◽  
Initiation Phase ◽  
Genes Encoding

In Saccharomyces cerevisiae, starvation for a single amino acid results in the derepression of enzyme activities in multiple amino acid biosynthetic pathways. Derepression is a consequence of increased transcription of the genes encoding these enzymes. Analysis of the kinetics of mRNA elevation established that derepression occurs within 5 min of a shift of the culture from rich medium to starvation medium. Any starvation condition was sufficient to trigger an initial high mRNA elevation; however, it was the severity of starvation which determined the steady-state mRNA levels that were subsequently established. The products of the positive regulatory genes AAS101, AAS103, and AAS2 were shown to be required in the initiation phase of this response, whereas the AAS102 gene product was required to maintain the new elevated steady-state mRNA levels. The AAS101 and AAS102 genes were cloned. Consistent with their respective roles in initiation and maintenance of derepression. AAS101 mRNA was found to be expressed at high levels in both rich and starvation media, whereas AAS102 mRNA was derepressed only under starvation conditions. The derepression of AAS102 mRNA is dependent on the AAS101 gene product.

scholarly journals Ribosomal protein S14 is encoded by a pair of highly conserved, adjacent genes on the X chromosome of Drosophila melanogaster.

1988 ◽  
Vol 8 (10) ◽  
pp. 4314-4321 ◽  
Author(s):  
S J Brown ◽  
D D Rhoads ◽  
M J Stewart ◽  
B Van Slyke ◽  
I T Chen ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Drosophila Melanogaster ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Ribosomal Protein ◽  
X Chromosome ◽  
Duplicated Genes ◽  
Ribosomal Protein Genes ◽  
Yeast Saccharomyces Cerevisiae ◽  
Genes Encoding

We describe a Drosophila DNA clone of tandemly duplicated genes encoding an amino acid sequence nearly identical to human ribosomal protein S14 and yeast rp59. Despite their remarkably similar exons, the locations and sizes of introns differ radically among the Drosophila, human, and yeast (Saccharomyces cerevisiae) ribosomal protein genes. Transcripts of both Drosophila RPS14 genes were detected in embryonic and adult tissues and are the same length as mammalian S14 message. Drosophila RPS14 was mapped to region 7C5-9 on the X chromosome. This interval also encodes a previously characterized Minute locus, M(1)7C.

scholarly journals CLN1 and Its Repression by Xbp1 Are Important for Efficient Sporulation in Budding Yeast

2000 ◽  
Vol 20 (2) ◽  
pp. 478-487 ◽  
Author(s):  
Bernard Mai ◽  
Linda Breeden
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Differential Display ◽  
Mitotic Cycle ◽  
Target Genes ◽  
Budding Yeast ◽  
Transcriptional Repressor ◽  
Primary Target ◽  
New Class ◽  
Genes Encoding ◽  
Meiotic Cycle

ABSTRACT Xbp1, a transcriptional repressor of Saccharomyces cerevisiae with homology to Swi4 and Mbp1, is induced by stress and starvation during the mitotic cycle. It is also induced late in the meiotic cycle. Using RNA differential display, we find that genes encoding three cyclins (CLN1, CLN3, andCLB2), CYS3, and SMF2 are downregulated when Xbp1 is overexpressed and that Xbp1 can bind to sequences in their promoters. During meiosis, XBP1 is highly induced and its mRNA appears at the same time asDIT1 mRNA, but its expression remains high for up to 24 h. As such, it represents a new class of meiosis-specific genes. Xbp1-deficient cells are capable of forming viable gametes, although ascus formation is delayed by several hours. Furthermore, Xbp1 target genes are normally repressed late in meiosis, and loss ofXBP1 results in their derepression. Interestingly, we find that a deletion of CLN1 also reduces the efficiency of sporulation and delays the meiotic program but that sporulation in a Δcln1 Δxbp1 strain is not further delayed. Thus, CLN1 may be Xbp1's primary target in meiotic cells. We hypothesize that CLN1 plays a role early in the meiotic program but must be repressed, by Xbp1, at later stages to promote efficient sporulation.

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