Truncated form of tenascin-X, XB-S, interacts with mitotic motor kinesin Eg5
Truncated form of tenascin-X, XB-S, interacts with mitotic motor kinesin Eg5
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DOI：
10.1007/s11010-008-9898-y
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发表时间：
2009-01-01
影响因子：
4.3
通讯作者：
Matsumoto, Ken-ichi
中科院分区：
文献类型：
--
作者：
Endo, Toshiya;Ariga, Hiroyoshi;Matsumoto, Ken-ichi
XB-S是一种具有腱生蛋白-X（TNXB）的氨基末端截短形式的蛋白质。然而，XB-S在体内的确切作用尚不清楚。在这项研究中，为了确定XB-S在体内的作用，我们筛选了XB-S结合蛋白。将FLAG标记的XB-S瞬时引入293 T细胞。然后用抗FLAG抗体免疫沉淀法纯化其相关蛋白，并通过质谱分析鉴定其组分。在免疫沉淀物中鉴定出有丝分裂运动驱动蛋白Eg 5。在分裂间期和有丝分裂期，XB-S和Eg 5蛋白共定位于细胞质中，但在有丝分裂期，XB-S蛋白不定位于纺锤体微管上，而Eg 5蛋白主要定位于纺锤体微管上。至于Eg 5与XB-S的结合，体外表达的谷胱甘肽S-转移酶融合的XB-S直接与网织红细胞裂解物中翻译的全长Eg 5结合，并且XB-S结合区域位于Eg 5的马达结构域。此外，在细胞周期进程中，XB-S显示出与Eg 5相似的表达谱。这些结果表明XB-S可能参与Eg 5的功能。
XB-S is a protein with an amino-terminal-truncated form of tenascin-X (TNXB). However, the precise roles of XB-S in vivo are unknown. In this study, to determine the role of XB-S in vivo, we screened XB-S-binding proteins. FLAG-tagged XB-S was transiently introduced into 293T cells. Then its associated proteins were purified by immunoprecipitation using an anti-FLAG antibody and its components were identified by mass spectrometric analyses. Mitotic motor kinesin Eg5 was identified in the immunoprecipitates. XB-S and Eg5 proteins were co-localized in the cytoplasm in interphase and mitosis, but XB-S did not localize on mitotic spindle microtubules, on which Eg5 prominently localized in mitosis. As for Eg5 binding to XB-S, glutathione S-transferase-fused XB-S expressed in vitro directly bound to full-length Eg5 translated in reticulocyte lysate, and the XB-S-binding region was located in the motor domain of Eg5. Furthermore, during cell cycle progression XB-S showed a similar expression profile to that of Eg5. These results suggest possible involvement of XB-S in the function of Eg5.