ACTIN MUTATIONS THAT SHOW SUPPRESSION WITH FIMBRIN MUTATIONS IDENTIFY A LIKELY FIMBRIN-BINDING SITE ON ACTIN
ACTIN MUTATIONS THAT SHOW SUPPRESSION WITH FIMBRIN MUTATIONS IDENTIFY A LIKELY FIMBRIN-BINDING SITE ON ACTIN
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DOI：
10.1083/jcb.126.2.413
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发表时间：
1994-07-01
影响因子：
7.8
通讯作者：
ADAMS, AEM
中科院分区：
文献类型：
--
作者：
HONTS, JE;SANDROCK, TS;ADAMS, AEM
肌动蛋白与大量不同的蛋白质相互作用，调节其组装并介导其功能。一种这样的蛋白质是酵母肌动蛋白结合蛋白Sac 6 p，其与脊椎动物的fimplant同源（亚当斯，A. E. M.，D. Botstein和D. G.德鲁宾1991.自然（伦敦）。354：404-408）。Sac 6p最初在遗传学上被鉴定（亚当斯，A. E. M.，和D.波特斯坦1989.遗传学121：675-683.）通过显性的、对温度敏感的酵母肌动蛋白突变（act 1 -1）的相互抑制，以及生物化学（Drubin，D. G.，K. G.米勒和D.波特斯坦1988. 107：2551-2561）。为了确定肌动蛋白上与Sac 6p相互作用的区域，我们分析了8种不同的act 1突变，这些突变显示出对Sac 6突变等位基因的抑制，并询问了（a）这些突变是否发生在肌动蛋白晶体结构上的一个小的限定区域;（B）突变肌动蛋白在体外与Sac 6p的相互作用中有缺陷。序列分析表明，所有这些突变改变了肌动蛋白晶体结构的小结构域中聚集的残基，这表明该区域是Sac 6p结合结构域的重要部分。生化分析揭示了缺陷的能力的几个突变体肌动蛋白结合Sac 6p，并减少Sac 6p诱导的交联的突变体肌动蛋白丝。总之，这些观察结果确定了一个可能的网站的相互作用的fimplanton肌动蛋白。
Actin interacts with a large number of different proteins that modulate its assembly and mediate its functions. One such protein is the yeast actin-binding protein Sac6p, which is homologous to vertebrate fimbrin (Adams, A. E. M., D. Botstein, and D. G. Drubin. 1991. Nature (Lond.). 354:404-408.). Sac6p was originally identified both genetically (Adams, A. E. M., and D. Botstein. 1989. Genetics. 121:675-683.) by dominant, reciprocal suppression of a temperature-sensitive yeast actin mutation (act1-1), as well as biochemically (Drubin, D. G., K. G. Miller, and D. Botstein. 1988. J. Cell Biol. 107: 2551-2561.). To identify the region on actin that interacts with Sac6p, we have analyzed eight different act1 mutations that show suppression with sac6 mutant alleles, and have asked whether (a) these mutations occur in a small defined region on the crystal structure of actin; and (b) the mutant actins are defective in their interaction with Sac6p in vitro. Sequence analysis indicates that all of these mutations change residues that cluster in the small domain of the actin crystal structure, suggesting that this region is an important part of the Sac6p-binding domain. Biochemical analysis reveals defects in the ability of several of the mutant actins to bind Sac6p, and a reduction in Sac6p-induced cross-linking of mutant actin filaments. Together, these observations identify a likely site of interaction of fimbrin on actin.