Hackney David D
Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
J Cell Biol. 2007 Jan 1;176(1):7-9. doi: 10.1083/jcb.200611082.
When it is not actively transporting cargo, conventional Kinesin-1 is present in the cytoplasm in a folded conformation that cannot interact effectively with microtubules (MTs). Two important and largely unexplored aspects of kinesin regulation are how it is converted to an active species when bound to cargo and the related issue of how kinesin discriminates among its many potential cargo molecules. Blasius et al. (see p. 11 of this issue) report that either binding of the cargo linker c-Jun N-terminal kinase-interacting protein 1 (JIP1) to the light chains (LCs) or binding of fasciculation and elongation protein zeta1 (FEZ1) to the heavy chains (HCs) is insufficient for activation but that activation occurs when both are present simultaneously. A related paper by Cai et al. (see p. 51 of this issue) provides structural insight into the conformation of the folded state in the cell obtained by fluorescence resonance energy transfer analysis.
在不积极运输货物时，传统的驱动蛋白-1以折叠构象存在于细胞质中，这种构象无法与微管（MTs）有效相互作用。驱动蛋白调节的两个重要且在很大程度上未被探索的方面是，当与货物结合时它如何转变为活性形式，以及驱动蛋白如何在众多潜在货物分子中进行区分这一相关问题。布拉修斯等人（见本期第11页）报告称，货物连接蛋白c-Jun氨基末端激酶相互作用蛋白1（JIP1）与轻链（LCs）的结合或成束和延伸蛋白zeta1（FEZ1）与重链（HCs）的结合都不足以激活驱动蛋白，但当两者同时存在时会发生激活。蔡等人的一篇相关论文（见本期第51页）通过荧光共振能量转移分析，对细胞中折叠状态的构象提供了结构上的见解。
