title: DNA sequences from Arabidopsis, which encode protein kinases and function as upstream regulators of Snf1 in yeast.
abstract: Sucrose nonfermenting-1 (Snf1)-related protein kinase-1 (SnRK1) of plants is a global regulator of carbon metabolism through the modulation of enzyme activity and gene expression. It is structurally and functionally related to the yeast protein kinase, Snf1, and to mammalian AMP-activated protein kinase. Two DNA sequences from Arabidopsis thaliana, previously known only by their data base accession numbers of NM_ 125448.3 (protein ID NP_200863) and NM_114393.3 (protein ID NP_566876) each functionally complemented a Saccharomyces cerevisiae elm1 sak1 tos3 triple mutant. This indicates that the Arabidopsis proteins are able to substitute for one of the missing yeast upstream kinases, which are required for activity of Snf1. Both plant proteins were shown to phosphorylate a peptide with the amino acid sequence of the phosphorylation site in the T-loop of SnRK1 and by inference SnRK1 in Arabidopsis. The proteins encoded by NM_125448.3 and NM_114393.3 have been named AtSnAK1 and AtSnAK2 (Arabidopsis thaliana SnRK1-activating kinase), respectively. We believe this is the first time that upstream activators of SnRK1 have been described in any plant species.
authors.affiliation: Department of Crop Performance and Improvement, Rothamsted Research, Harpenden AL5 2JQ, United Kingdom.
authors.forename: Sandra
authors.initials: S
authors.lastname: Hey
authors.forename: Hubert
authors.initials: H
authors.lastname: Mayerhofer
authors.forename: Nigel G
authors.initials: NG
authors.lastname: Halford
authors.forename: J Richard
authors.initials: JR
authors.lastname: Dickinson
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D005816:Genetic Complementation Test; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis* / Q000235:genetics; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid
chemical_list: D029681:Arabidopsis Proteins; D029701:Saccharomyces cerevisiae Proteins; C071570:SNF1-related protein kinases; D017346:Protein Serine-Threonine Kinases