酵母蛋白激酶Sch9激活环磷酸化状态参与热胁迫应答调控

Phosphorylation of Yeast Protein Kinase Sch9 Regulates Heat Stress Response

在酵母(Saccharomyces cerevisiae)中,蛋白激酶Sch9已经被证明与细胞大小、胁迫应答、自噬以及寿命的调控有关.通过不同基因型酵母在固体培养基上的热敏感性研究,发现Sch9的激酶功能与热胁迫相关,进一步通过Sch9特异磷酸化位点抗体的免疫印迹,检测了细胞内Sch9关键的激活环T570位点(PDK1位点)在热胁迫条下的磷酸化状态,发现半乳糖诱导表达的Sch9在热胁迫条件下T570位点去磷酸化,首次证明了Sch9通过调控激酶活性参与细胞热胁迫应答.研究结果揭示了Sch9在胁迫应答中的部分功能,并为生理条件下Sch9调控功能的研究提供了生物化学证据.

Protein kinase Sch9 has been implicated in regulation of cell size,stress resistance,autophagy and aging in Saccharomyces cerevisiae.Based on the results of the heat sensitivity of different yeasts which grew on solid medium,it was revealed that the kinase activity of Sch9 was related to heat stress response.An in-depth study,immunoblotting was carried out by phosphospecific antibody to detect the phosphorylation of Thr570（PDK1 site） under heat stress.It was found that Thr570 was dephosphorylated under heat stress,demonstrating that Sch9,which was induced to express by galactose,altered its kinase activity in response to heat stress for the first time.In conclusion,this study revealed some stress response functions of Sch9 and provided preliminary biochemistry evidences for Sch9 function research under physiological condition