Yeast PAS kinase coordinates glucose partitioning in response to metabolic and cell integrity signaling

EMBO J. 2007 Nov 28;26(23):4824-30. doi: 10.1038/sj.emboj.7601914. Epub 2007 Nov 8.

Abstract

PAS kinase is an evolutionarily conserved serine/threonine protein kinase. Mammalian PAS kinase is activated under nutrient replete conditions and is important for controlling metabolic rate and energy homeostasis. In yeast, PAS kinase acts to increase the synthesis of structural carbohydrate at the expense of storage carbohydrates through phosphorylation of the enzyme UDP-glucose pyrophosphorylase. We have identified two pathways that activate yeast PAS kinase; one is responsive to nutrient conditions while the other is responsive to cell integrity stress. These pathways differentially activate the two PAS kinase proteins in Saccharomyces cerevisiae, Psk1 and Psk2, with Psk1 alone responding to activation by nonfermentative carbon sources. We demonstrate that, in addition to transcriptional effects, both of these pathways post-translationally activate PAS kinase via its regulatory N-terminus. As a whole, this system acts to coordinate glucose partitioning with alterations in demand due to changes in environmental and nutrient conditions.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carbon / chemistry
  • Enzyme Activation
  • Fungal Proteins / chemistry
  • Gene Expression Regulation, Fungal
  • Glucose / metabolism
  • Homeostasis
  • Models, Biological
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / metabolism
  • Protein-Serine-Threonine Kinases / physiology*
  • Saccharomyces cerevisiae / enzymology*
  • Saccharomyces cerevisiae / metabolism
  • Signal Transduction
  • Transcription, Genetic
  • UTP-Glucose-1-Phosphate Uridylyltransferase / metabolism

Substances

  • Fungal Proteins
  • Carbon
  • PAS domain kinases
  • Protein-Serine-Threonine Kinases
  • UTP-Glucose-1-Phosphate Uridylyltransferase
  • Glucose