Reindl A, Schöffl F, Schell J, Koncz C, Bakó L
Universität Tübingen, Biologisches Institut, Germany.
Plant Physiol. 1997 Sep;115(1):93-100. doi: 10.1104/pp.115.1.93.
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.
磷酸化是控制酵母和哺乳动物细胞中热休克转录因子活性的机制之一。在此，我们描述了一种蛋白激酶的部分纯化、鉴定及特性，该激酶可在多个丝氨酸残基处磷酸化拟南芥热休克因子AtHSF1。HSF1激酶与AtHSF1形成稳定复合物，这可通过使用组氨酸标记的AtHSF1底物的激酶下拉试验检测到。HSF1激酶与细胞周期控制蛋白Suc1p相互作用，并被针对拟南芥细胞周期蛋白依赖性CDC2a激酶的特异性抗体免疫沉淀。体外CDC2a介导的磷酸化抑制AtHSF1与同源热休克元件的DNA结合，这表明植物中热休克反应与细胞周期控制之间可能存在调节相互作用。
