title: The moss genes PpSKI1 and PpSKI2 encode nuclear SnRK1 interacting proteins with homologues in vascular plants.
abstract: The yeast Snf1, animal AMPK, and plant SnRK1 protein kinases constitute a family of related proteins that have been proposed to serve as metabolic sensors of the eukaryotic cell. We have previously reported the characterization of two redundant SnRK1 encoding genes (PpSNF1a and PpSNF1b) in the moss Physcomitrella patens. Phenotypic analysis of the snf1a snf1b double knockout mutant suggested that SnRK1 is important for the plant's ability to recognize and adapt to conditions of limited energy supply, and also suggested a possible role of SnRK1 in the control of plant development. We have now used a yeast two-hybrid system to screen for PpSnf1a interacting proteins. Two new moss genes were found, PpSKI1 and PpSKI2, which encode highly similar proteins with homologues in vascular plants. Fusions of the two encoded proteins to the green fluorescent protein localize to the nucleus. Knockout mutants for either gene have an excess of gametophores under low light conditions, and exhibit reduced gametophore stem lengths. Possible functions of the new proteins and their connection to the SnRK1 kinase are discussed.
authors.affiliation: Department of Plant Biology and Forest Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden. Mattias.Thelander@vbsg.slu.se
authors.forename: Mattias
authors.initials: M
authors.lastname: Thelander
authors.forename: Anders
authors.initials: A
authors.lastname: Nilsson
authors.forename: Tina
authors.initials: T
authors.lastname: Olsson
authors.forename: Monika
authors.initials: M
authors.lastname: Johansson
authors.forename: Pierre-Alain
authors.initials: PA
authors.lastname: Girod
authors.forename: Didier G
authors.initials: DG
authors.lastname: Schaefer
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Zrÿd
authors.forename: Hans
authors.initials: H
authors.lastname: Ronne
mesh_terms: D000595:Amino Acid Sequence; D044002:Bryophyta / Q000201:enzymology* / Q000235:genetics; D017124:Conserved Sequence; D017353:Gene Deletion; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D005838:Genotype; D008969:Molecular Sequence Data; D005810:Multigene Family; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: C071570:SNF1-related protein kinases; D017346:Protein Serine-Threonine Kinases