title: Mitochondrial porin Por1 and its homolog Por2 contribute to the positive control of Snf1 protein kinase in Saccharomyces cerevisiae.
abstract: Saccharomyces cerevisiae Snf1 is a member of the conserved Snf1/AMP-activated protein kinase (Snf1/AMPK) family involved in regulating responses to energy limitation, which is detected by mechanisms that include sensing adenine nucleotides. Mitochondrial voltage-dependent anion channel (VDAC) proteins, also known as mitochondrial porins, are conserved in eukaryotes from yeast to humans and play key roles in mediating mitochondrial outer membrane permeability to small metabolites, including ATP, ADP, and AMP. We previously recovered the yeast mitochondrial porin Por1 (yVDAC1) from a two-hybrid screen for Snf1-interacting proteins. Here, we present evidence that Snf1 interacts with Por1 and its homolog Por2 (yVDAC2). Cells lacking Por1 and Por2, but not respiratory-deficient rho(0) cells lacking the mitochondrial genome, exhibit reduced Snf1 activation loop phosphorylation in response to glucose limitation. Thus, Por1 and Por2 contribute to the positive control of Snf1 protein kinase. Physical proximity to the VDAC proteins and mitochondrial surface could facilitate Snf1's ability to sense energy limitation.
authors.affiliation: Department of Biological Sciences, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin, USA.
authors.forename: Vera
authors.initials: V
authors.lastname: Strogolova
authors.forename: Marianna
authors.initials: M
authors.lastname: Orlova
authors.forename: Aishwarya
authors.initials: A
authors.lastname: Shevade
authors.forename: Sergei
authors.initials: S
authors.lastname: Kuchin
mesh_terms: D054629:Genome, Mitochondrial; D010766:Phosphorylation; D018272:Porins / Q000235:genetics* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism; D050995:Voltage-Dependent Anion Channel 1 / Q000235:genetics* / Q000378:metabolism; D050996:Voltage-Dependent Anion Channel 2 / Q000235:genetics* / Q000378:metabolism
chemical_list: C580894:Por1 protein, S cerevisiae; C580895:Por2 protein, S cerevisiae; D018272:Porins; D029701:Saccharomyces cerevisiae Proteins; D050996:Voltage-Dependent Anion Channel 2; D050995:Voltage-Dependent Anion Channel 1; C071570:SNF1-related protein kinases; D017346:Protein Serine-Threonine Kinases