Phosphorylation by a cyclin-dependent kinase modulates DNA binding of the Arabidopsis heat-shock transcription factor HSF1 in vitro.
Phosphorylation is one of the mechanisms controlling the activity of heat-shock transcription factors in yeast and mammalian cells. Here we describe partial purification, identification, and characterization of a protein kinase that phosphorylates the Arabidopsis heat-shock factor AtHSF1 at multiple serine residues. The HSF1 kinase forms a stable complex with AtHSF1, which can be detected by kinase pull-down assays using a histidine-tagged AtHSF1 substrate. The HSF1 kinase interacts with the cell-cycle control protein Suc1p and is immunoprecipitated by an antibody specific for the Arabidopsis cyclin-dependent CDC2a kinase. Phosphorylation by CDC2a in vitro inhibits DNA binding of AtHSF1 to the cognate heat-shock elements, suggesting a possible regulatory interaction between heat-shock response and cell-cycle control in plants.
Reindl
A
A
Universität Tübingen, Biologisches Institut, Germany.
Schöffl
F
F
Schell
J
J
Koncz
C
C
Bakó
L
L
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins; D001665:Binding Sites; D016203:CDC2 Protein Kinase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002453:Cell Cycle; D018744:DNA, Plant / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010940:Plant Proteins; D012694:Serine; D014157:Transcription Factors / Q000378:metabolism*
D029681:Arabidopsis Proteins; D018744:DNA, Plant; D004268:DNA-Binding Proteins; C000620151:HSF1 protein, Arabidopsis; D000076249:Heat Shock Transcription Factors; D006360:Heat-Shock Proteins; D010940:Plant Proteins; D014157:Transcription Factors; D012694:Serine; D016203:CDC2 Protein Kinase