Yang F, Demma M, Warren V, Dharmawardhane S, Condeelis J
Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York 10461.
Nature. 1990 Oct 4;347(6292):494-6. doi: 10.1038/347494a0.
Indirect evidence has implicated an interaction between the cytoskeleton and the protein synthetic machinery. Two recent reports have linked the elongation factor 1a (EF-1a) which is involved in protein synthesis, with the microtubular cytoskeleton. In situ hybridization has, however, revealed that the messages for certain cytoskeletal proteins are preferentially associated with actin filaments. ABP-50 is an abundant actin filament bundling protein of native relative molecular mass 50,000 (50K) isolated from Dictyostelium discoideum. Immunofluorescence studies show that ABP-50 is present in filopodia and other cortical regions that contain actin filament bundles. In addition, ABP-50 binds to monomeric actin in the cytosol of unstimulated cells and the association of ABP-50 with the actin cytoskeleton is regulated during chemotaxis. Through complementary DNA sequencing and subsequent functional analysis, we have identified ABP-50 as D. discoideum EF-1a. The ability of EF-1a to bind reversibly to the actin cytoskeleton upon stimulation could provide a mechanism for spatially and temporally regulated protein synthesis in eukaryotic cells.
间接证据表明细胞骨架与蛋白质合成机制之间存在相互作用。最近的两份报告将参与蛋白质合成的延伸因子1a（EF-1a）与微管细胞骨架联系起来。然而，原位杂交显示某些细胞骨架蛋白的信使优先与肌动蛋白丝相关。ABP-50是一种从盘基网柄菌中分离出的、天然相对分子质量为50000（50K）的丰富的肌动蛋白丝成束蛋白。免疫荧光研究表明，ABP-50存在于丝状伪足和其他含有肌动蛋白丝束的皮质区域。此外，ABP-50在未受刺激细胞的胞质溶胶中与单体肌动蛋白结合，并且在趋化作用期间ABP-50与肌动蛋白细胞骨架的结合受到调节。通过互补DNA测序及随后的功能分析，我们已将ABP-50鉴定为盘基网柄菌EF-1a。EF-1a在受到刺激时可逆地结合到肌动蛋白细胞骨架上的能力，可为真核细胞中蛋白质合成的时空调节提供一种机制。
