A comprehensive protein-protein interactome for yeast PAS kinase 1 reveals direct inhibition of respiration through the phosphorylation of Cbf1.
Per-Arnt-Sim (PAS) kinase is a sensory protein kinase required for glucose homeostasis in yeast, mice, and humans, yet little is known about the molecular mechanisms of its function. Using both yeast two-hybrid and copurification approaches, we identified the protein-protein interactome for yeast PAS kinase 1 (Psk1), revealing 93 novel putative protein binding partners. Several of the Psk1 binding partners expand the role of PAS kinase in glucose homeostasis, including new pathways involved in mitochondrial metabolism. In addition, the interactome suggests novel roles for PAS kinase in cell growth (gene/protein expression, replication/cell division, and protein modification and degradation), vacuole function, and stress tolerance. In vitro kinase studies using a subset of 25 of these binding partners identified Mot3, Zds1, Utr1, and Cbf1 as substrates. Further evidence is provided for the in vivo phosphorylation of Cbf1 at T211/T212 and for the subsequent inhibition of respiration. This respiratory role of PAS kinase is consistent with the reported hypermetabolism of PAS kinase-deficient mice, identifying a possible molecular mechanism and solidifying the evolutionary importance of PAS kinase in the regulation of glucose homeostasis.
Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602.
Desiree
D
DeMille
Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT 84602.
Benjamin T
BT
Bikman
Department of Chemistry, Brigham Young University, Provo, UT 84602.
Andrew D
AD
Mathis
Department of Chemistry, Brigham Young University, Provo, UT 84602.
John T
JT
Prince
Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602.
Jordan T
JT
Mackay
Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602.
Steven W
SW
Sowa
Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602.
Tacie D
TD
Hall
Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT 84602 julianne_grose@byu.edu.
Julianne H
JH
Grose
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000378:metabolism*; D008928:Mitochondria / Q000201:enzymology; D010101:Oxygen Consumption; D010766:Phosphorylation; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D020543:Proteome / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D020798:Two-Hybrid System Techniques
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; C064042:CBF1 protein, S cerevisiae; D020543:Proteome; D029701:Saccharomyces cerevisiae Proteins; D011494:Protein Kinases; C467888:PSK1 protein, S cerevisiae