title: Ptc1 protein phosphatase 2C contributes to glucose regulation of SNF1/AMP-activated protein kinase (AMPK) in Saccharomyces cerevisiae.
abstract: The SNF1/AMP-activated protein kinases (AMPKs) function in energy regulation in eukaryotic cells. SNF1/AMPKs are αβγ heterotrimers that are activated by phosphorylation of the activation loop Thr on the catalytic subunit. Protein kinases that activate SNF1/AMPK have been identified, but the protein phosphatases responsible for dephosphorylation of the activation loop are less well defined. For Saccharomyces cerevisiae SNF1/AMPK, Reg1-Glc7 protein phosphatase 1 and Sit4 type 2A-related phosphatase function together to dephosphorylate Thr-210 on the Snf1 catalytic subunit during growth on high concentrations of glucose; reg1Δ and sit4Δ single mutations do not impair dephosphorylation when inappropriate glycogen synthesis, also caused by these mutations, is blocked. We here present evidence that Ptc1 protein phosphatase 2C also has a role in dephosphorylation of Snf1 Thr-210 in vivo. The sit4Δ ptc1Δ mutant exhibited partial defects in regulation of the phosphorylation state of Snf1. The reg1Δ ptc1Δ mutant was viable only when expressing mutant Snf1 proteins with reduced kinase activity, and Thr-210 phosphorylation of the mutant SNF1 heterotrimers was substantially elevated during growth on high glucose. This evidence, together with findings on the reg1Δ sit4Δ mutant, indicates that although Reg1-Glc7 plays the major role, all three phosphatases contribute to maintenance of the Snf1 activation loop in the dephosphorylated state during growth on high glucose. Ptc1 has overlapping functions with Reg1-Glc7 and Sit4 in glucose regulation of SNF1/AMPK and cell viability.
authors.affiliation: From the Department of Genetics and Development, Columbia University, New York, New York 10032.
authors.forename: Amparo
authors.initials: A
authors.lastname: Ruiz
authors.forename: Xinjing
authors.initials: X
authors.lastname: Xu
authors.forename: Marian
authors.initials: M
authors.lastname: Carlson
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain; D017353:Gene Deletion; D005947:Glucose / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000502:physiology; D054645:Protein Phosphatase 1 / Q000235:genetics / Q000378:metabolism; D054648:Protein Phosphatase 2 / Q000235:genetics / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D029701:Saccharomyces cerevisiae Proteins; C071570:SNF1-related protein kinases; D017346:Protein Serine-Threonine Kinases; D055372:AMP-Activated Protein Kinases; C092048:GLC7 protein, S cerevisiae; C087358:PTC1 protein, S cerevisiae; D054645:Protein Phosphatase 1; D054648:Protein Phosphatase 2; C070829:REG1 protein, S cerevisiae; C104343:SIT4 protein, S cerevisiae; D005947:Glucose
keywords: AMP-activated Kinase (AMPK); Glucose; Phosphorylation; Protein Phosphatase; Yeast Genetics
references.citation: J Biol Chem. 2006 Nov 17;281(46):35057-69
references.pmid: 16973600
references.citation: Front Biosci. 2008 Jan 01;13:2408-20
references.pmid: 17981722
references.citation: Biochem J. 2006 Mar 15;394(Pt 3):545-55
references.pmid: 16396636
references.citation: Mol Cell Biol. 2010 Jun;30(12):2862-73
references.pmid: 20404097
references.citation: Mol Cell Biol. 2009 May;29(10):2876-88
references.pmid: 19273591
references.citation: Genes Dev. 2011 Sep 15;25(18):1895-908
references.pmid: 21937710
references.citation: Cell Signal. 2011 Jan;23(1):114-24
references.pmid: 20801214
references.citation: J Cell Sci. 2011 Jan 1;124(Pt 1):35-46
references.pmid: 21118957
references.citation: J Biol Chem. 2008 Jan 4;283(1):222-230
references.pmid: 17991748
references.citation: Genetics. 1989 May;122(1):19-27
references.pmid: 2659436
references.citation: J Biol Chem. 2005 Jun 10;280(23):21804-9
references.pmid: 15831494
references.citation: Nat Methods. 2012 Jul;9(7):671-5
references.pmid: 22930834
references.citation: Yeast. 2003 Jan 30;20(2):157-69
references.pmid: 12518319
references.citation: Yeast. 2003 Aug;20(11):985-93
references.pmid: 12898713
references.citation: EMBO J. 1995 Dec 1;14(23):5939-46
references.pmid: 8846786
references.citation: Eukaryot Cell. 2011 Jan;10(1):21-33
references.pmid: 21076010
references.citation: Mol Cell Biol. 2000 Feb;20(4):1321-8
references.pmid: 10648618
references.citation: J Biol Chem. 1994 Jul 29;269(30):19509-15
references.pmid: 7913470
references.citation: Genetics. 2010 Jan;184(1):91-105
references.pmid: 19841091
references.citation: Proc Natl Acad Sci U S A. 2012 May 29;109(22):8652-7
references.pmid: 22589305
references.citation: J Biol Chem. 2001 Sep 28;276(39):36460-6
references.pmid: 11486005
references.citation: Mol Cell Biol. 1991 Apr;11(4):2133-48
references.pmid: 1848673
references.citation: J Biol Chem. 2011 Jul 1;286(26):23544-51
references.pmid: 21561858
references.citation: Gene. 1987;60(2-3):237-43
references.pmid: 3327750
references.citation: J Biol Chem. 2006 Oct 27;281(43):32207-16
references.pmid: 16943194
references.citation: J Biol Chem. 2011 Dec 30;286(52):44532-41
references.pmid: 22065577
references.citation: Mol Microbiol. 2006 Oct;62(1):263-77
references.pmid: 16956380
references.citation: Mol Cell Biol. 1996 Jun;16(6):2744-55
references.pmid: 8649382
references.citation: Mol Cell Biol. 1989 Nov;9(11):5034-44
references.pmid: 2557546
references.citation: Eukaryot Cell. 2011 Mar;10(3):313-9
references.pmid: 21216941
references.citation: Proc Natl Acad Sci U S A. 2011 Apr 19;108(16):6349-54
references.pmid: 21464305
references.citation: Biochem J. 2007 Apr 1;403(1):139-48
references.pmid: 17147517
references.citation: Science. 1999 Aug 6;285(5429):901-6
references.pmid: 10436161
references.citation: Genes Dev. 1996 Aug 1;10(15):1904-16
references.pmid: 8756348
references.citation: FASEB J. 2010 Dec;24(12):5080-91
references.pmid: 20724523
references.citation: Proc Natl Acad Sci U S A. 1998 May 26;95(11):6245-50
references.pmid: 9600950
references.citation: Cell. 2010 Dec 10;143(6):991-1004
references.pmid: 21145464
references.citation: Cell Metab. 2011 Nov 2;14(5):707-14
references.pmid: 22019086
references.citation: Mol Cell Biol. 2011 Aug;31(15):3126-35
references.pmid: 21628526