Yeast PAS kinase coordinates glucose partitioning in response to metabolic and cell integrity signaling.
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.
Grose
Julianne H
JH
Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT 84112, USA.
Smith
Tammy L
TL
Sabic
Hana
H
Rutter
Jared
J
D002244:Carbon / Q000737:chemistry; D004789:Enzyme Activation; D005656:Fungal Proteins / Q000737:chemistry; D015966:Gene Expression Regulation, Fungal; D005947:Glucose / Q000378:metabolism; D006706:Homeostasis; D008954:Models, Biological; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism / Q000502:physiology*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000378:metabolism; D015398:Signal Transduction; D014158:Transcription, Genetic; D005957:UTP-Glucose-1-Phosphate Uridylyltransferase / Q000378:metabolism
D005656:Fungal Proteins; D002244:Carbon; C116037:PAS domain kinases; D017346:Protein Serine-Threonine Kinases; D005957:UTP-Glucose-1-Phosphate Uridylyltransferase; D005947:Glucose