Protein kinase C regulates endocytosis and recycling of E-cadherin
Protein kinase C regulates endocytosis and recycling of E-cadherin
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DOI：
10.1152/ajpcell.00566.2001
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发表时间：
2002-08-01
影响因子：
5.5
通讯作者：
Stow, JL
中科院分区：
文献类型：
--
作者：
Le, TL;Joseph, SR;Stow, JL
E-钙粘蛋白是上皮细胞粘附连接的主要成分。我们之前表明，细胞表面 E-钙粘蛋白池被组成性内化并循环回到表面。在本研究中，我们研究了蛋白激酶 C (PKC) 在调节 Madin-Darby 犬肾细胞表面 E-钙粘蛋白运输中的潜在作用。使用表面生物素化和免疫荧光，我们发现用佛波酯处理细胞增加了 E-钙粘蛋白的内吞速率，导致 E-钙粘蛋白在顶部局部早期或循环内体中积累。在佛波酯存在的情况下，E-钙粘蛋白返回表面的再循环也会减少。佛波酯诱导的 E-钙粘蛋白内吞作用被特定抑制剂阻断，表明该途径中存在新的 PKC 同工酶，例如 PKC-epsilon。 PKC 激活导致肌动蛋白细胞骨架发生变化，促进 E-钙粘蛋白内吞作用。肌动蛋白的解聚增加了 E-钙粘蛋白的内吞作用，而 PKC 诱导的 E-钙粘蛋白的摄取被肌动蛋白稳定剂 jasplakinolide 阻断。我们的研究结果表明，PKC 调节 E-钙粘蛋白运输、内吞作用和再循环的重要步骤。
E-cadherin is a major component of adherens junctions in epithelial cells. We showed previously that a pool of cell surface E-cadherin is constitutively internalized and recycled back to the surface. In the present study, we investigated the potential role of protein kinase C (PKC) in regulating the trafficking of surface E-cadherin in Madin-Darby canine kidney cells. Using surface biotinylation and immunofluorescence, we found that treatment of cells with phorbol esters increased the rate of endocytosis of E-cadherin, resulting in accumulation of E-cadherin in apically localized early or recycling endosomes. The recycling of E-cadherin back to the surface was also decreased in the presence of phorbol esters. Phorbol ester-induced endocytosis of E-cadherin was blocked by specific inhibitors, implicating novel PKC isozymes, such as PKC-epsilon in this pathway. PKC activation led to changes in the actin cytoskeleton facilitating E-cadherin endocytosis. Depolymerization of actin increased endocytosis of E-cadherin, whereas the PKC-induced uptake of E-cadherin was blocked by the actin stabilizer jasplakinolide. Our findings show that PKC regulates vital steps of E-cadherin trafficking, its endocytosis, and its recycling.