title: AKIN10, a representative Arabidopsis SNF1-related protein kinase 1 (SnRK1), phosphorylates and downregulates plant HMG-CoA reductase.
abstract: HMG-CoA reductase (HMGR) is a key enzyme in the mevalonate pathway for sterols and cytosolic isoprenoid production. Although HMGR kinases from spinach, barley, and cauliflower tissues have been strongly suggested as members of SNF1-related protein kinases 1 (SnRK1), the phosphorylation and inactivation of HMGR by plant SnRK1s has not been demonstrated. In this study, we elucidated that AKIN10, an Arabidopsis SnRK1, acts as an HMGR kinase. The recombinant AKIN10 phosphorylates and inactivates AtHMGR1S using recombinant GRIK1 as the AKIN10 activator. In contrast, AKIN10-GRIK1 fails to inactivate AtHMGR1S-S577A, suggesting that this is achieved through Ser577 phosphorylation. Moreover, phosphorylation is detected not only in AtHMGR1S but also in AtHMGR1S-S577A, suggesting the presence of a novel regulatory mechanism of plant HMGR.
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Japan.
authors.forename: Jekson
authors.initials: J
authors.lastname: Robertlee
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Japan.|Department of Chemical and Biological Sciences, Faculty of Science, Japan Women's University, Tokyo, Japan.
authors.forename: Keiko
authors.initials: K
authors.lastname: Kobayashi
authors.affiliation: Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Suzuki
authors.affiliation: Department of Biotechnology, Graduate School of Engineering, Osaka University, Suita, Japan.
authors.forename: Toshiya
authors.initials: T
authors.lastname: Muranaka
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D017360:Arabidopsis / Q000201:enzymology* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020134:Catalytic Domain; D017124:Conserved Sequence; D004789:Enzyme Activation; D004794:Enzyme Repression; D018506:Gene Expression Regulation, Plant; D028482:Hevea / Q000201:enzymology; D025782:Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D010446:Peptide Fragments / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D010940:Plant Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D054730:Protein Interaction Domains and Motifs; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D029681:Arabidopsis Proteins; D025782:Hydroxymethylglutaryl-CoA-Reductases, NADP-dependent; D010446:Peptide Fragments; D010940:Plant Proteins; D017346:Protein Serine-Threonine Kinases; D011994:Recombinant Proteins; D012694:Serine; C000606223:HMGR protein, Arabidopsis; C518082:GRIK1 protein, Arabidopsis; C531469:At3g01090 protein, Arabidopsis
keywords: 
  HMGR
  ; GRIK1; SnRK1; isoprenoid; phosphorylation