Vainberg I E, Lewis S A, Rommelaere H, Ampe C, Vandekerckhove J, Klein H L, Cowan N J
Department of Biochemistry, New York University Medical Center, New York 10016, USA.
Cell. 1998 May 29;93(5):863-73. doi: 10.1016/s0092-8674(00)81446-4.
We describe the discovery of a heterohexameric chaperone protein, prefoldin, based on its ability to capture unfolded actin. Prefoldin binds specifically to cytosolic chaperonin (c-cpn) and transfers target proteins to it. Deletion of the gene encoding a prefoldin subunit in S. cerevisiae results in a phenotype similar to those found when c-cpn is mutated, namely impaired functions of the actin and tubulin-based cytoskeleton. Consistent with prefoldin having a general role in chaperonin-mediated folding, we identify homologs in archaea, which have a class II chaperonin but contain neither actin nor tubulin. We show that by directing target proteins to chaperonin, prefoldin promotes folding in an environment in which there are many competing pathways for nonnative proteins.
我们基于其捕获未折叠肌动蛋白的能力，描述了一种异源六聚体伴侣蛋白——前折叠素的发现。前折叠素特异性结合胞质伴侣蛋白（c-cpn）并将靶蛋白转移给它。在酿酒酵母中缺失编码前折叠素亚基的基因会导致一种类似于c-cpn发生突变时所发现的表型，即基于肌动蛋白和微管蛋白的细胞骨架功能受损。与前折叠素在伴侣蛋白介导的折叠过程中具有普遍作用相一致，我们在古细菌中鉴定出了同源物，这些古细菌具有II类伴侣蛋白，但既不含肌动蛋白也不含微管蛋白。我们表明，通过将靶蛋白导向伴侣蛋白，前折叠素在存在许多针对非天然蛋白的竞争途径的环境中促进折叠。
