Transcriptional regulation plays an important role in cellular homeostasis, regulating internal rhythms of the cell and its response to the external milieu. The cellular response to nutrient deprivation requires coordination of gene expression to insure that appropriate enzymes and cofactors are synthesized to meet the metabolic needs of the organism. Diabetes and metabolic syndrome are examples of two human diseases that arise when the metabolic response to caloric intake is not appropriately regulated at multiple levels, include transcriptional ones. Although not a disease strictly speaking, aging is another condition whose age of onset and severity is affected by nutrient stress, or caloric restriction, acting in part through transcriptional pathways affecting chromatin organization. The stress imposed by nutrient deprivation has been particularly well-studied in the budding yeast Saccharomyces cerevisiae. As in multicellular eukaryotes, metabolic stress in yeast is sensed and transmitted through an enzyme cascade that includes a complex protein kinase, the AMP-activated protein kinase (AMPK). The activity of the kinase cascade is modulated by a protein phosphatase complex. The targets of the kinase and phosphatase complexes include transcription factors and chromatin components as well as enzymes catalyzing key metabolic reactions in carbon source utilization. One important nutrient stress is glucose deprivation. In yeast as in other organisms, glucose starvation requires the organism to utilize other less readily available sources of carbon. These alternative energy sources are metabolized by pathways that are not utilized when glucose is available, a process called carbon catabolite repression or simply glucose repression. AMPK is activated when glucose is not available, and its activity serves as a switch to turn on numerous genes whose activity is necessary to process poorer carbon substrates such as ethanol, glycerol, and lactate, or to breakdown reserve carbohydrates and lipids, or to utilize alternative fermentable carbon sources. In our previous work we characterized two important transcription factors, Adr1 and Cat8, which are activated by AMPK. In the present proposal we focus on the characterization of an apparently novel protein phosphatase complex involved in gene repression, the chromatin changes that influence Adr1 binding, and the identification and characterization of upstream pathways that regulate the binding and activity of Adr1. ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM026079-29
Application #
7270459
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Program Officer
Anderson, James J
Project Start
1978-12-01
Project End
2010-06-30
Budget Start
2007-08-01
Budget End
2010-06-30
Support Year
29
Fiscal Year
2007
Total Cost
$491,288
Indirect Cost
Name
University of Washington
Department
Biochemistry
Type
Schools of Medicine
DUNS #
605799469
City
Seattle
State
WA
Country
United States
Zip Code
98195
Braun, Katherine A; Dombek, Kenneth M; Young, Elton T (2016) Snf1-Dependent Transcription Confers Glucose-Induced Decay upon the mRNA Product. Mol Cell Biol 36:628-44
Braun, Katherine A; Vaga, Stefania; Dombek, Kenneth M et al. (2014) Phosphoproteomic analysis identifies proteins involved in transcription-coupled mRNA decay as targets of Snf1 signaling. Sci Signal 7:ra64
Braun, Katherine A; Young, Elton T (2014) Coupling mRNA synthesis and decay. Mol Cell Biol 34:4078-87
Parua, Pabitra K; Young, Elton T (2014) Binding and transcriptional regulation by 14-3-3 (Bmh) proteins requires residues outside of the canonical motif. Eukaryot Cell 13:21-30
Parua, Pabitra K; Dombek, Kenneth M; Young, Elton T (2014) Yeast 14-3-3 protein functions as a comodulator of transcription by inhibiting coactivator functions. J Biol Chem 289:35542-60
Braun, Katherine A; Parua, Pabitra K; Dombek, Kenneth M et al. (2013) 14-3-3 (Bmh) proteins regulate combinatorial transcription following RNA polymerase II recruitment by binding at Adr1-dependent promoters in Saccharomyces cerevisiae. Mol Cell Biol 33:712-24
Infante, Juan Jose; Law, G Lynn; Young, Elton T (2012) Analysis of nucleosome positioning using a nucleosome-scanning assay. Methods Mol Biol 833:63-87
Young, Elton T; Zhang, Chao; Shokat, Kevan M et al. (2012) The AMP-activated protein kinase Snf1 regulates transcription factor binding, RNA polymerase II activity, and mRNA stability of glucose-repressed genes in Saccharomyces cerevisiae. J Biol Chem 287:29021-34
Abate, Georgia; Bastonini, Emanuela; Braun, Katherine A et al. (2012) Snf1/AMPK regulates Gcn5 occupancy, H3 acetylation and chromatin remodelling at S. cerevisiae ADY2 promoter. Biochim Biophys Acta 1819:419-27
Parua, Pabitra K; Ryan, Paul M; Trang, Kayla et al. (2012) Pichia pastoris 14-3-3 regulates transcriptional activity of the methanol inducible transcription factor Mxr1 by direct interaction. Mol Microbiol 85:282-98

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