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The Hsp70 homolog Ssb and the 14-3-3 protein Bmh1 jointly regulate transcription of glucose repressed genes in Saccharomyces cerevisiae
- Source :
- Nucleic Acids Research
- Publication Year :
- 2016
- Publisher :
- Oxford University Press, 2016.
-
Abstract
- Chaperones of the Hsp70 family interact with a multitude of newly synthesized polypeptides and prevent their aggregation. Saccharomyces cerevisiae cells lacking the Hsp70 homolog Ssb suffer from pleiotropic defects, among others a defect in glucose-repression. The highly conserved heterotrimeric kinase SNF1/AMPK (AMP-activated protein kinase) is required for the release from glucose-repression in yeast and is a key regulator of energy balance also in mammalian cells. When glucose is available the phosphatase Glc7 keeps SNF1 in its inactive, dephosphorylated state. Dephosphorylation depends on Reg1, which mediates targeting of Glc7 to its substrate SNF1. Here we show that the defect in glucose-repression in the absence of Ssb is due to the ability of the chaperone to bridge between the SNF1 and Glc7 complexes. Ssb performs this post-translational function in concert with the 14-3-3 protein Bmh, to which Ssb binds via its very C-terminus. Raising the intracellular concentration of Ssb or Bmh enabled Glc7 to dephosphorylate SNF1 even in the absence of Reg1. By that Ssb and Bmh efficiently suppressed transcriptional deregulation of Δreg1 cells. The findings reveal that Ssb and Bmh comprise a new chaperone module, which is involved in the fine tuning of a phosphorylation-dependent switch between respiration and fermentation.
- Subjects :
- 0301 basic medicine
Saccharomyces cerevisiae Proteins
Transcription, Genetic
Saccharomyces cerevisiae
Phosphatase
Protein Serine-Threonine Kinases
Dephosphorylation
03 medical and health sciences
Heterotrimeric G protein
Protein Phosphatase 1
Genetics
HSP70 Heat-Shock Proteins
Phosphorylation
Protein kinase A
Adenosine Triphosphatases
biology
Respiration
fungi
Gene regulation, Chromatin and Epigenetics
Protein phosphatase 1
biology.organism_classification
stomatognathic diseases
030104 developmental biology
Glucose
Biochemistry
14-3-3 Proteins
Chaperone (protein)
Fermentation
biology.protein
Subjects
Details
- Language :
- English
- ISSN :
- 13624962 and 03051048
- Volume :
- 44
- Issue :
- 12
- Database :
- OpenAIRE
- Journal :
- Nucleic Acids Research
- Accession number :
- edsair.doi.dedup.....3fbcd9f3f973999f93ac16bedc133278