Watts N R, Sackett D L, Ward R D, Miller M W, Wingfield P T, Stahl S S, Steven A C
Laboratory of Structural Biology Research, National Institute of Arthritis and Musculoskeletal and Skin Diseases, Bethesda, MD, USA.
J Cell Biol. 2000 Jul 24;150(2):349-60. doi: 10.1083/jcb.150.2.349.
We describe a novel interaction between HIV-1 Rev and microtubules (MTs) that results in the formation of bilayered rings that are 44-49 nm in external diameter, 3.4-4.2 MD (megadaltons) in mass, and have 28-, 30-, or 32-fold symmetry. Ring formation is not sensitive to taxol, colchicine, or microtubule-associated proteins, but requires Mg(2+) and is inhibited by maytansine. The interaction involves the NH(2)-terminal domain of Rev and the face of tubulin exposed on the exterior of the MTs. The NH(2)-terminal half of Rev has unexpected sequence similarity to the tubulin-binding portion of the catalytic/motor domains of the microtubule-destabilizing Kin I kinesins. We propose a model wherein binding of Rev dimers to MTs at their ends causes segments of two neighboring protofilaments to peel off and close into rings, circumferentially containing 14, 15, or 16 tubulin heterodimers, with Rev bound on the inside. Rev has a strong inhibitory effect on aster formation in Xenopus egg extracts, demonstrating that it can interact with tubulin in the presence of normal levels of cellular constituents. These results suggest that Rev may interact with MTs to induce their destabilization, a proposition consistent with the previously described disruption of MTs after HIV-1 infection.
我们描述了一种HIV-1 Rev与微管（MTs）之间的新型相互作用，这种相互作用导致形成了外径为44 - 49纳米、质量为3.4 - 4.2兆道尔顿（MD）且具有28、30或32重对称性的双层环。环的形成对紫杉醇、秋水仙碱或微管相关蛋白不敏感，但需要Mg(2+)，并被美登素抑制。这种相互作用涉及Rev的NH(2)末端结构域以及微管外部暴露的微管蛋白表面。Rev的NH(2)末端一半与微管去稳定化Kin I驱动蛋白的催化/运动结构域的微管蛋白结合部分具有意外的序列相似性。我们提出了一个模型，其中Rev二聚体在微管末端与微管结合，导致两个相邻原纤维的片段剥离并闭合形成环，环周向包含14、15或16个微管蛋白异二聚体，Rev结合在内部。Rev对非洲爪蟾卵提取物中的星体形成有强烈抑制作用，表明它可以在正常细胞成分水平存在的情况下与微管蛋白相互作用。这些结果表明Rev可能与微管相互作用以诱导其去稳定化，这一观点与先前描述的HIV-1感染后微管的破坏一致。
