Sternlicht H, Farr G W, Sternlicht M L, Driscoll J K, Willison K, Yaffe M B
Department of Pharmacology, Case Western Reserve University, Cleveland, OH 44106.
Proc Natl Acad Sci U S A. 1993 Oct 15;90(20):9422-6. doi: 10.1073/pnas.90.20.9422.
A role in folding newly translated cytoskeletal proteins in the cytosol of eukaryotes has been proposed for t-complex polypeptide 1 (TCP1). In this study, we investigated tubulin and actin biogenesis in Chinese hamster ovary (CHO) cells. When extracts of pulse-labeled cells were analyzed by anion-exchange and size-exclusion chromatography, newly synthesized alpha-tubulin, beta-tubulin, and actin were observed to enter a large molecular mass complex (approximately 900 kDa). These proteins were released from this complex capable, in the case of tubulin, of forming heterodimers. The large molecular mass complexes coeluted with TCP1 and could be immunoprecipitated by using an anti-TCP1 antibody. These findings demonstrate that there is a cytosolic pathway for folding tubulin and actin in vivo that involves the TCP1 complex.
有人提出，真核生物细胞质中t-复合体多肽1（TCP1）在新翻译的细胞骨架蛋白折叠过程中发挥作用。在本研究中，我们调查了中国仓鼠卵巢（CHO）细胞中微管蛋白和肌动蛋白的生物合成。当通过阴离子交换和尺寸排阻色谱分析脉冲标记细胞的提取物时，观察到新合成的α-微管蛋白、β-微管蛋白和肌动蛋白进入一个大分子质量复合物（约900 kDa）。这些蛋白质从该复合物中释放出来，就微管蛋白而言，能够形成异二聚体。大分子质量复合物与TCP1共洗脱，并且可以使用抗TCP1抗体进行免疫沉淀。这些发现表明，体内存在一条涉及TCP1复合物的微管蛋白和肌动蛋白折叠的胞质途径。
