Steady-state analysis of glucose repression reveals hierarchical expression of proteins under Mig1p control in Saccharomyces cerevisiae
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Title |
Steady-state analysis of glucose repression reveals hierarchical expression of proteins under Mig1p control in Saccharomyces cerevisiae
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Creator |
VERMA, M
BHAT, PJ VENKATESH, KV |
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Subject |
yeast gal genes
catabolite repression binding switch activator promoter growth model transcription sensitivity glucose repression mig1p mitogen-activated protein kinase (mapk) transcriptional activator transcriptional repressor yeast |
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Description |
Glucose repression is a global transcriptional regulatory mechanism commonly observed in micro-organisms for the repression of enzymes that are not essential for glucose metabolism. In Saccharomyces cerevisiae, Mig1p, a homologue of Wilms' tumour protein, is a global repressor protein dedicated to glucose repression. Mig1p represses genes either by binding directly to the upstream repression sequence of structural genes or by indirectly repressing a transcriptional activator, such as Ga14p. In addition, some genes are repressed by both of the above mechanisms. This raises a fundamental question regarding the physiological relevance of the varied mechanisms of repression that exist involving Mig1p. We address this issue by comparing two well-known glucose-repression systems, that is, SUC2 and GAL gene expression systems, which encompass all the above three mechanisms. We demonstrate using steady-state analysis that these mechanisms lead to a hierarchical glucose repression profile of different family of genes. This switch over from one carbon source to another is well-calibrated as a function of glucose concentration through this hierarchical transcriptional response. The mechanisms prevailing in this repression system can achieve amplification and sensitivity, as observed in the well-characterized MAPK (mitogen-activated protein kinase) cascade system, albeit through a different structure. A critical feature of repression predicted by our steady-state model for the mutant strain of S. cerevisiae lacking Gal80p agrees well with the data reported here as well as that available in the literature.
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Publisher |
PORTLAND PRESS LTD
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Date |
2011-08-27T07:10:58Z
2011-12-26T12:57:47Z 2011-12-27T05:45:16Z 2011-08-27T07:10:58Z 2011-12-26T12:57:47Z 2011-12-27T05:45:16Z 2005 |
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Type |
Article
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Identifier |
BIOCHEMICAL JOURNAL, 388(), 843-849
0264-6021 http://dx.doi.org/10.1042/BJ20041883 http://dspace.library.iitb.ac.in/xmlui/handle/10054/11581 http://hdl.handle.net/10054/11581 |
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Language |
en
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