Targeting of p0071 to the midbody depends on KIF3
Targeting of p0071 to the midbody depends on KIF3
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DOI：
10.1242/jcs.045377
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发表时间：
2009-04-15
影响因子：
4
通讯作者：
Hatzfeld, Mechthild
中科院分区：
文献类型：
--
作者：
Keil, Rene;Kiessling, Christina;Hatzfeld, Mechthild
P0071（plakophilin-4）是犰狳蛋白p120 ctn亚家族的成员，对细胞接触形成至关重要。此外，p0071在胞质分裂中起作用，其中它与Ect 2一起调节RhoA的局部激活。由于通过胞质分裂的进展需要时空调节，我们分析了何时以及如何将p0071靶向至中间体以诱导RhoA激活。我们发现，Ect 2之前p0071积累在中间体和目标是由不同的马达蛋白介导的。p0071与驱动蛋白-II家族成员KIF 3b相互作用，并且KIF 3b的敲低干扰p0071中间体募集，而Ect 2或RhoA定位在这些细胞中不受影响。此外，KIF 3b的敲低诱导了与p0071敲低相似的表型，在胞质分裂期间减少了肌动蛋白和磷酸肌球蛋白轻链在中间体的积累，并降低了活性RhoA的水平。在KIF 3b缺陷细胞中RhoA活化的缺乏没有通过野生型p0071的过表达而被拯救，但是通过p0071-MKLP 1-马达结构域融合蛋白而被显著改善，该融合蛋白独立于KIF 3靶向沟。这些数据表明，p0071和Ect 2是通过不同的电机运输，并确定了一个新的途径，涉及KIF 3在细胞质分裂过程中的肌动蛋白组织的调节。
P0071 (plakophilin-4) is a member of the p120ctn subfamily of armadillo proteins that are essential for cell contact formation. Additionally, p0071 plays a role in cytokinesis, in which it regulates local activation of RhoA together with Ect2. Because spatiotemporal regulation is required for progression through cytokinesis, we analyzed when and how p0071 is targeted to the midbody to induce RhoA activation. We show that Ect2 precedes p0071 accumulation at the midbody and that targeting is mediated by different motor proteins. p0071 interacted with the kinesin-II family member KIF3b, and knockdown of KIF3b interfered with p0071 midbody recruitment whereas Ect2 or RhoA localization was not affected in these cells. Moreover, knockdown of KIF3b induced a similar phenotype as the p0071 knockdown, with reduced actin and phospho-myosin-light-chain accumulation at the midbody and decreased levels of active RhoA during cytokinesis. The lack of RhoA activation in KIF3b-deficient cells was not rescued by overexpression of wild-type p0071 but was substantially ameliorated by a p0071-MKLP1-motor-domain fusion protein that was targeted to the furrow independently of KIF3. These data indicate that p0071 and Ect2 are transported via distinct motors and identify a novel pathway implicating KIF3 in the regulation of actin organization during cytokinesis.