Bregier Cezary, Kupikowska Barbara, Fabczak Hanna, Fabczak Stanisław
Zakład Biologii Komórki, Instytut Biologii Doświadczalnej im. Marcelego Nenckiego PAN, Warszawa.
Postepy Biochem. 2008;54(1):64-70.
Chaperonins are large oligomers consisting of two superimposed rings, each enclosing a cavity used for the folding of other proteins. They have been divided into two groups. Chaperonins of type I were identified in mitochondria and chloroplasts (Hsp60) or bacterial cytosol (GroEL) as well. Chaperonins type II were found in Archea and the eukaryotic cell cytosol (CCT). Protein folding occurs in the chaperonin after its conformational changes induced upon ATP binding. Mechanism of the protein folding, although still poorly defined, clearly differs from the one established for GroEL. Although CCT with prefoldin seems to be mainly involved in the folding of actin and tubulin, other substrates engaged in various cellular processes are beginning to be characterized, including proteins possessing WD40-repeats. Moreover, several lines of evidence suggest that beside prefoldin, CCT may work in concert with phosducin-like proteins (PhLPs).
伴侣蛋白是由两个叠加环组成的大型寡聚体，每个环都包围着一个用于其他蛋白质折叠的腔。它们已被分为两组。I型伴侣蛋白在线粒体和叶绿体（Hsp60）或细菌细胞质（GroEL）中也有发现。II型伴侣蛋白存在于古细菌和真核细胞细胞质（CCT）中。蛋白质折叠在伴侣蛋白结合ATP后诱导其构象变化后发生。蛋白质折叠的机制虽然仍不清楚，但显然与GroEL的机制不同。尽管带有前折叠蛋白的CCT似乎主要参与肌动蛋白和微管蛋白的折叠，但其他参与各种细胞过程的底物也开始被鉴定，包括具有WD40重复序列的蛋白质。此外，有几条证据表明，除了前折叠蛋白外，CCT可能与视紫红质样蛋白（PhLPs）协同作用。
