Endocytosis Is Required for Efficient Apical Constriction during Xenopus Gastrulation
Endocytosis Is Required for Efficient Apical Constriction during Xenopus Gastrulation
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DOI：
10.1016/j.cub.2009.12.021
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发表时间：
2010-02-09
期刊：
影响因子：
9.2
通讯作者：
Harland, Richard M.
中科院分区：
文献类型：
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作者：
Lee, Jen-Yi;Harland, Richard M.
上皮片中的协调顶端收缩(AC)驱动组织内陷[1，2]，并且是各种形态发生运动所必需的，如原肠形成[3]、神经形成[4，5]和器官发生[6]。我们以前曾证明，在非洲爪哇的瓶状细胞中，肌动球蛋白的收缩能力驱动AC[7]；然而，目前尚不清楚它是否与其他过程协同作用。在这里，我们报告内吞作用驱动的膜重塑是有效的AC所必需的。我们在原肠胚早期的瓶状细胞中发现了专门存在的内体。用显性-负性Dynamin或Rab5干扰AC的内吞作用，在这个过程的后期收缩速率显著降低，这表明内吞作用在肌球蛋白收缩能力的下游进行，以清除多余的膜。此外，在神经形成过程中扰乱内吞作用会抑制铰点细胞中的AC，导致神经管闭合缺陷。因此，AC过程中的膜重塑可能是实现胚胎有效内陷的一般机制。
Coordinated apical constriction (AC) in epithelial sheets drives tissue invagination [1, 2] and is required for diverse morphogenetic movements such as gastrulation [3], neurulation [4, 5], and organogenesis [6]. We showed previously that actomyosin contractility drives AC in Xenopus laevis bottle cells [7]; however, it remained unclear whether it does so in concert with other processes. Here we report that endocytosis-driven membrane remodeling is required for efficient AC. We found endosomes exclusively in bottle cells in the early gastrula. Disrupting endocytosis with dominant-negative dynamin or rab5 perturbed AC, with a significant decrease in constriction rate late in the process, suggesting that endocytosis operates downstream of actomyosin contractility to remove excess membrane. Additionally, disrupting endocytosis during neurulation inhibits AC in hingepoint cells, resulting in neural tube closure defects. Thus, membrane remodeling during AC could be a general mechanism to achieve efficient invagination in embryos.