scholarly journals Functional domains in the Mig1 repressor.

1996 ◽  
Vol 16 (3) ◽  
pp. 753-761 ◽  
Author(s):  
J Ostling ◽  
M Carlberg ◽  
H Ronne
Keyword(s):  
Zinc Finger Protein ◽  
Wilms Tumor ◽  
Glucose Repression ◽  
Protein A ◽  
Carbon Sources ◽  
Negative Control ◽  
Functional Domains ◽  
Deletion Mapping ◽  
Yeast Saccharomyces Cerevisiae ◽  
Finger Protein

Mig1 is a zinc finger protein that mediates glucose repression in the yeast Saccharomyces cerevisiae. It is related to the mammalian Krox/Egr, Wilms' tumor, and Sp1 proteins and binds to a GC-rich motif that resembles the GC boxes recognized by these proteins. We have performed deletion mapping in order to identify functional domains in Mig1. We found that a small C-terminal domain comprising the last 24 amino acids mediates Mig1-dependent repression of a reporter gene. This effector domain contains several leucine-proline dipeptide repeats. We further found that inhibition of Mig1 activity in the absence of glucose is mediated by two internal elements in the Mig1 protein. A Mig1-VP16 hybrid activator was used to further investigate how Mig1 is regulated. Mig1-VP16 can activate transcription from promoters containing Mig1-binding sites and suppresses the inability of Snf1-deficient cells to grow on certain carbon sources. We found that a deletion of the SNF1 gene increases the activity of Mig1-VP16 fivefold under derepressing conditions but not in the presence of glucose. This shows that the hybrid activator is under negative control by the Snf1 protein kinase. Deletion mapping within Mig1-VP16 revealed that regulation of its activity by Snf1 is conferred by the same internal elements in the Mig1 sequence that mediate inhibition of Mig1 activity in the absence of glucose.

Importance of a flanking AT-rich region in target site recognition by the GC box-binding zinc finger protein MIG1

1994 ◽  
Vol 14 (3) ◽  
pp. 1979-1985
Author(s):  
M Lundin ◽  
J O Nehlin ◽  
H Ronne
Keyword(s):  
Dna Binding ◽  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Wilms Tumor ◽  
Glucose Repression ◽  
Saturation Mutagenesis ◽  
Sequence Specificity ◽  
Rich Region ◽  
Finger Protein ◽  
Gc Box

MIG1 is a zinc finger protein that mediates glucose repression in the yeast Saccharomyces cerevisiae. MIG1 is related to the mammalian Krox/Egr, Wilms' tumor, and Sp1 finger proteins. It has two fingers and binds to a GCGGGG motif that resembles the GC boxes recognized by these mammalian proteins. We have performed a complete saturation mutagenesis of a natural MIG1 site in order to elucidate its binding specificity. We found that only three mutations within the GC box retain the ability to bind MIG1: G1 to C, C2 to T, and G5 to A. This result is consistent with current models for zinc finger-DNA binding, which assume that the sequence specificity is determined by base triplet recognition within the GC box. Surprisingly, we found that an AT-rich region 5' to the GC box also is important for MIG1 binding. This AT box is present in all natural MIG1 sites, and it is protected by MIG1 in DNase I footprints. However, the AT box differs from the GC box in that no single base within it is essential for binding. Instead, the AT-rich nature of this sequence seems to be crucial. The fact that AT-rich sequences are known to increase DNA flexibility prompted us to test whether MIG1 bends DNA. We found that binding of MIG1 is associated with bending within the AT box. We conclude that DNA binding by a simple zinc finger protein such as MIG1 can involve both recognition of the GC box and flanking sequence preferences that may reflect local DNA bendability.

scholarly journals Importance of a flanking AT-rich region in target site recognition by the GC box-binding zinc finger protein MIG1.

1994 ◽  
Vol 14 (3) ◽  
pp. 1979-1985 ◽  
Author(s):  
M Lundin ◽  
J O Nehlin ◽  
H Ronne
Keyword(s):  
Dna Binding ◽  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Wilms Tumor ◽  
Glucose Repression ◽  
Saturation Mutagenesis ◽  
Sequence Specificity ◽  
Rich Region ◽  
Finger Protein ◽  
Gc Box

MIG1 is a zinc finger protein that mediates glucose repression in the yeast Saccharomyces cerevisiae. MIG1 is related to the mammalian Krox/Egr, Wilms' tumor, and Sp1 finger proteins. It has two fingers and binds to a GCGGGG motif that resembles the GC boxes recognized by these mammalian proteins. We have performed a complete saturation mutagenesis of a natural MIG1 site in order to elucidate its binding specificity. We found that only three mutations within the GC box retain the ability to bind MIG1: G1 to C, C2 to T, and G5 to A. This result is consistent with current models for zinc finger-DNA binding, which assume that the sequence specificity is determined by base triplet recognition within the GC box. Surprisingly, we found that an AT-rich region 5' to the GC box also is important for MIG1 binding. This AT box is present in all natural MIG1 sites, and it is protected by MIG1 in DNase I footprints. However, the AT box differs from the GC box in that no single base within it is essential for binding. Instead, the AT-rich nature of this sequence seems to be crucial. The fact that AT-rich sequences are known to increase DNA flexibility prompted us to test whether MIG1 bends DNA. We found that binding of MIG1 is associated with bending within the AT box. We conclude that DNA binding by a simple zinc finger protein such as MIG1 can involve both recognition of the GC box and flanking sequence preferences that may reflect local DNA bendability.

scholarly journals Regulated nuclear translocation of the Mig1 glucose repressor.

1997 ◽  
Vol 8 (8) ◽  
pp. 1603-1618 ◽  
Author(s):  
M J De Vit ◽  
J A Waddle ◽  
M Johnston
Keyword(s):  
Nuclear Import ◽  
Zinc Finger Protein ◽  
Nuclear Translocation ◽  
Glucose Repression ◽  
Signal Transduction Pathway ◽  
Yeast Saccharomyces Cerevisiae ◽  
Finger Protein ◽  
Repression Complex ◽  
Import And Export ◽  
Necessary And Sufficient

Glucose represses the transcription of many genes in bakers yeast (Saccharomyces cerevisiae). Mig1 is a Cys2-His2 zinc finger protein that mediates glucose repression of several genes by binding to their promoters and recruiting the general repression complex Ssn6-Tup1. We have found that the subcellular localization of Mig1 is regulated by glucose. Mig1 is imported into the nucleus within minutes after the addition of glucose and is just as rapidly transported back to the cytoplasm when glucose is removed. This regulated nuclear localization requires components of the glucose repression signal transduction pathway. An internal region of the protein separate from the DNA binding and repression domains is necessary and sufficient for glucose-regulated nuclear import and export. Changes in the phosphorylation status of Mig1 are coincident with the changes in its localization, suggesting a possible regulatory role for phosphorylation. Our results suggest that a glucose-regulated nuclear import and/or export mechanism controls the activity of Mig1.

Two homologous zinc finger genes identified by multicopy suppression in a SNF1 protein kinase mutant of Saccharomyces cerevisiae

1993 ◽  
Vol 13 (7) ◽  
pp. 3872-3881
Author(s):  
F Estruch ◽  
M Carlson
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Wilms Tumor ◽  
Temperature Sensitive ◽  
Carbon Utilization ◽  
Functional Roles ◽  
Multicopy Suppressor ◽  
Finger Protein

The MSN2 gene was selected as a multicopy suppressor in a temperature-sensitive SNF1 protein kinase mutant of Saccharomyces cerevisiae. MSN2 encodes a Cys2His2 zinc finger protein related to the yeast MIG1 repressor and to mammalian early growth response and Wilms' tumor zinc finger proteins. Deletion of MSN2 caused no phenotype. A second similar zinc finger gene, MSN4, was isolated, and deletion of both genes caused phenotypic defects related to carbon utilization. Overexpression of the zinc finger regions was deleterious to growth. LexA-MSN2 and LexA-MSN4 fusion proteins functioned as strong transcriptional activators when bound to DNA. Functional roles of this zinc finger protein family are discussed.

scholarly journals Sequencing of Random Euplotes crassus Macronuclear Genes Supports a High Frequency of +1 Translational Frameshifting

2005 ◽  
Vol 4 (12) ◽  
pp. 2098-2105 ◽  
Author(s):  
Lawrence A. Klobutcher
Keyword(s):  
High Frequency ◽  
Zinc Finger Protein ◽  
Protein A ◽  
Recent Analysis ◽  
Proliferating Cells ◽  
Euplotes Crassus ◽  
Translational Frameshifting ◽  
Reverse Transcription Pcr ◽  
Finger Protein ◽  
Past Data

ABSTRACT Programmed translational frameshifts have been identified in genes from a broad range of organisms, but typically only a very few genes in a given organism require a frameshift for expression. In contrast, a recent analysis of gene sequences available in GenBank from ciliates in the genus Euplotes indicated that >5% required one or more +1 translational frameshifts to produce their predicted protein products. However, this sample of genes was nonrandom, biased, and derived from multiple Euplotes species. To test whether there truly is an abundance of frameshift genes in Euplotes, and to more accurately assess their frequency, we sequenced a random sample of 25 cloned genes/macronuclear DNA molecules from Euplotes crassus. Three new candidate +1 frameshift genes were identified in the sample that encode a membrane occupation and recognition nexus (MORN) repeat protein, a C2H2-type zinc finger protein, and a Ser/Thr protein kinase. Reverse transcription-PCR analyses indicate that all three genes are expressed in vegetatively proliferating cells and that the mRNAs retain the requirement of a frameshift. Although the sample of sequenced genes is relatively small, the results indicate that the frequency of genes requiring frameshifts in E. crassus is between 3.7% and 31.7% (at a 95% confidence interval). The current and past data also indicate that frameshift sites are found predominantly in genes that likely encode nonabundant proteins in the cell.

scholarly journals A common bacterial metabolite elicits prion-based bypass of glucose repression

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
David M Garcia ◽  
David Dietrich ◽  
Jon Clardy ◽  
Daniel F Jarosz
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Lactic Acid ◽  
Glucose Metabolism ◽  
Carbon Source ◽  
Glucose Repression ◽  
Carbon Sources ◽  
Yeast Cells ◽  
Genetic Element ◽  
Yeast Saccharomyces Cerevisiae ◽  
The Common

Robust preference for fermentative glucose metabolism has motivated domestication of the budding yeast Saccharomyces cerevisiae. This program can be circumvented by a protein-based genetic element, the [GAR+] prion, permitting simultaneous metabolism of glucose and other carbon sources. Diverse bacteria can elicit yeast cells to acquire [GAR+], although the molecular details of this interaction remain unknown. Here we identify the common bacterial metabolite lactic acid as a strong [GAR+] inducer. Transient exposure to lactic acid caused yeast cells to heritably circumvent glucose repression. This trait had the defining genetic properties of [GAR+], and did not require utilization of lactic acid as a carbon source. Lactic acid also induced [GAR+]-like epigenetic states in fungi that diverged from S. cerevisiae ~200 million years ago, and in which glucose repression evolved independently. To our knowledge, this is the first study to uncover a bacterial metabolite with the capacity to potently induce a prion.

Characterization of the isoforms of MOVO zinc finger protein, a mouse homologue of Drosophila Ovo, as transcription factors

Gene ◽  
2004 ◽  
Vol 336 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Sawako Unezaki ◽  
Mikio Nishizawa ◽  
Emiko Okuda-Ashitaka ◽  
Yasuo Masu ◽  
Masanori Mukai ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Zinc Finger ◽  
Zinc Finger Protein ◽  
Protein A ◽  
Mouse Homologue ◽  
Finger Protein
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