Shinoda Junro, Kikuchi Yoshiko
Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan.
Biochem Biophys Res Commun. 2007 Dec 14;364(2):258-63. doi: 10.1016/j.bbrc.2007.09.134. Epub 2007 Oct 12.
Metazoan arrestin proteins bind to seven-transmembrane proteins, mediate their internalization and play central roles in the subsequent signal transduction pathway. In Saccharomyces cerevisiae, there are several arrestin-related proteins. One of those proteins, Rod1, has been identified to have the ability to confer resistance to o-dinitrobenzene. We found that Rod1 interacted with Snf4, a subunit of Snf1-kinase complex. Both snf4 and snf1 mutants were also sensitive to the drug and the kinase activity of Snf1 was required for the drug tolerance. In immunoblotting analysis, the Rod1 protein was phosphorylated in an Snf1-dependent manner in vivo, and the phosphorylation of the serine residue 447 of Rod1 was responsible for the band-shift. Furthermore, the Rod1 protein was directly phosphorylated by Snf1-kinase in vitro. The substitution of the serine residue 447 to alanine slightly enhanced the resistance to the drug. We discuss possible functions of Rod1.
后生动物抑制蛋白与七跨膜蛋白结合，介导其内化，并在随后的信号转导途径中发挥核心作用。在酿酒酵母中，有几种与抑制蛋白相关的蛋白。其中一种蛋白Rod1已被鉴定具有赋予对邻二硝基苯抗性的能力。我们发现Rod1与Snf1激酶复合体的一个亚基Snf4相互作用。snf4和snf1突变体对该药物也敏感，并且Snf1的激酶活性是药物耐受性所必需的。在免疫印迹分析中，Rod1蛋白在体内以Snf1依赖的方式被磷酸化，并且Rod1丝氨酸残基447的磷酸化导致了条带迁移。此外，Rod1蛋白在体外被Snf1激酶直接磷酸化。将丝氨酸残基447替换为丙氨酸略微增强了对该药物的抗性。我们讨论了Rod1可能的功能。
