Cortical flows powered by asymmetrical contraction transport PAR proteins to establish and maintain anterior-posterior polarity in the early C-elegans embryo
Cortical flows powered by asymmetrical contraction transport PAR proteins to establish and maintain anterior-posterior polarity in the early C-elegans embryo
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DOI：
10.1016/j.devcel.2004.08.001
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发表时间：
2004-09-01
影响因子：
11.8
通讯作者：
Priess, JR
中科院分区：
文献类型：
--
作者：
Munro, E;Nance, J;Priess, JR
秀丽隐杆线虫的PAR蛋白PAR-3、PAR-6和PKC-3是不对称定位的，在细胞极性中起重要作用。我们表明，单细胞秀丽隐杆线虫胚胎包含一个动态和可收缩的肌动球蛋白网络，该网络似乎在精子进入点附近不稳定。这种不对称导致皮质非肌球蛋白（NMY-2）和f -肌动蛋白流向相反的未来前极。PAR-3、PAR-6和PKC-3，以及与细胞骨架相关的非par蛋白，似乎通过这种皮质流被转运到前侧。反过来，PAR-3、PAR-6和PKC-3调节皮质肌动球蛋白动力学并促进皮质血流。PAR-2位于后皮层，在血流过程中抑制NMY-2在后皮层积聚，从而通过防止不适当的后向血流维持不对称性。类似的肌动球蛋白流动伴随着单细胞期后PAR不对称的形成，这表明肌动球蛋白介导的皮质流动在PAR不对称中起着普遍作用。
The C. elegans PAR proteins PAR-3, PAR-6, and PKC-3 are asymmetrically localized and have essential roles in cell polarity. We show that the one-cell C. elegans embryo contains a dynamic and contractile actomyosin network that appears to be destabilized near the point of sperm entry. This asymmetry initiates a flow of cortical nonmuscle myosin (NMY-2) and F-actin toward the opposite, future anterior, pole. PAR-3, PAR-6, and PKC-3, as well as non-PAR proteins that associate with the cytoskeleton, appear to be transported to the anterior by this cortical flow. In turn, PAR-3, PAR-6, and PKC-3 modulate cortical actomyosin dynamics and promote cortical flow. PAR-2, which localizes to the posterior cortex, inhibits NMY-2 from accumulating at the posterior cortex during flow, thus maintaining asymmetry by preventing inappropriate, posterior-directed flows. Similar actomyosin flows accompany the establishment of PAR asymmetries that form after the one-cell stage, suggesting that actomyosin-mediated cortical flows have a general role in PAR asymmetry.