Regulated ADAM10-dependent ectodomain shedding of γ-protocadherin C3 modulates cell-cell adhesion
Regulated ADAM10-dependent ectodomain shedding of γ-protocadherin C3 modulates cell-cell adhesion
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DOI：
10.1074/jbc.m602663200
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发表时间：
2006-08-04
影响因子：
4.8
通讯作者：
Saftig, Paul
中科院分区：
文献类型：
--
作者：
Reiss, Karina;Maretzky, Thorsten;Saftig, Paul
γ-原钙粘蛋白（Pcdh γ）是I型跨膜蛋白，其最显著地在神经系统中表达。它们在突触处富集并参与突触的形成、特化和维持。在这项研究中，我们表明，Pcdh γ C3和Pcdh γ B4在其胞外域内的解整合素和金属蛋白酶ADAM 10特异性裂解。对ADAM 10缺陷的成纤维细胞和胚胎的分析、抑制剂研究以及RNA干扰介导的下调表明，ADAM 10不仅负责这些蛋白质在成纤维细胞和神经元细胞中的组成性脱落，而且还负责这些蛋白质在成纤维细胞和神经元细胞中的调节性脱落。与神经元细胞中由N-甲基-D-天冬氨酸受体激活而激活的N-钙粘蛋白脱落相反，α-氨基-3-羟基-5-甲基异恶唑-4-丙酸水合物刺激诱导Pcdh γ脱落，表明钙粘蛋白介导的突触功能的差异调节机制。在存在或不存在金属蛋白酶抑制剂的情况下的细胞聚集测定强烈表明，胞外域脱落事件调节Pcdh γ的细胞粘附作用。因此，鉴定ADAM 10作为负责组成性和调节性Pcdh γ脱落的蛋白酶可能为Pcdh γ功能的调节提供新的见解。
gamma-Protocadherins (Pcdh gamma) are type I transmembrane proteins, which are most notably expressed in the nervous system. They are enriched at synapses and involved in synapse formation, specification, and maintenance. In this study, we show that Pcdh gamma C3 and Pcdh gamma B4 are specifically cleaved within their ectodomains by the disintegrin and metalloprotease ADAM10. Analysis of ADAM10-deficient fibroblasts and embryos, inhibitor studies, as well as RNA interference-mediated down-regulation demonstrated that ADAM10 is not only responsible for the constitutive but also for the regulated shedding of these proteins in fibroblasts and in neuronal cells. In contrast to N-cadherin shedding, which was activated by N-methyl-D-aspartic acid receptor activation in neuronal cells, Pcdh gamma shedding was induced by alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid hydrate stimulation, suggesting differential regulation mechanisms of cadherin-mediated functions at synapses. Cell aggregation assays in the presence or absence of metalloprotease inhibitors strongly suggest that the ectodomain shedding events modulate the cell adhesion role of Pcdh gamma. The identification of ADAM10 as the protease responsible for constitutive and regulated Pcdh gamma shedding may therefore provide new insight into the regulation of Pcdh gamma functions.