Cytokinetics Inc, South San Francisco, CA 94080, USA.
Proc Natl Acad Sci U S A. 2010 Mar 30;107(13):5839-44. doi: 10.1073/pnas.0915068107. Epub 2010 Feb 18.
Centromere-associated protein-E (CENP-E) is a kinetochore-associated mitotic kinesin that is thought to function as the key receptor responsible for mitotic checkpoint signal transduction after interaction with spindle microtubules. We have identified GSK923295, an allosteric inhibitor of CENP-E kinesin motor ATPase activity, and mapped the inhibitor binding site to a region similar to that bound by loop-5 inhibitors of the kinesin KSP/Eg5. Unlike these KSP inhibitors, which block release of ADP and destabilize motor-microtubule interaction, GSK923295 inhibited release of inorganic phosphate and stabilized CENP-E motor domain interaction with microtubules. Inhibition of CENP-E motor activity in cultured cells and tumor xenografts caused failure of metaphase chromosome alignment and induced mitotic arrest, indicating that tight binding of CENP-E to microtubules is insufficient to satisfy the mitotic checkpoint. Consistent with genetic studies in mice suggesting that decreased CENP-E function can have a tumor-suppressive effect, inhibition of CENP-E induced tumor cell apoptosis and tumor regression.
着丝粒相关蛋白-E（CENP-E）是一种与动粒相关的有丝分裂驱动蛋白，被认为是与纺锤体微管相互作用后负责有丝分裂检查点信号转导的关键受体。我们已经鉴定出 GSK923295，这是一种 CENP-E 驱动蛋白马达 ATP 酶活性的别构抑制剂，并将抑制剂结合位点定位到与 KSP/Eg5 丝氨酸激酶的环 5 抑制剂结合的类似区域。与这些阻止 ADP 释放并破坏马达-微管相互作用的 KSP 抑制剂不同，GSK923295 抑制无机磷酸盐的释放并稳定 CENP-E 马达结构域与微管的相互作用。在培养细胞和肿瘤异种移植中抑制 CENP-E 驱动蛋白活性会导致中期染色体排列失败并诱导有丝分裂停滞，这表明 CENP-E 与微管的紧密结合不足以满足有丝分裂检查点的要求。与在小鼠中的遗传研究一致，即降低 CENP-E 功能可能具有肿瘤抑制作用，抑制 CENP-E 诱导肿瘤细胞凋亡和肿瘤消退。
