Extracellular cleavage of bullous pemphigoid antigen 180 type XVII collagen and its involvement in hemidesmosomal disassembly
Extracellular cleavage of bullous pemphigoid antigen 180 type XVII collagen and its involvement in hemidesmosomal disassembly
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DOI：
10.1093/jb/mvg024
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发表时间：
2003-02-01
影响因子：
2.7
通讯作者：
Owaribe, K
中科院分区：
文献类型：
--
作者：
Hirako, Y;Yoshino, K;Owaribe, K
大疱性类天疱疮抗原180(BP180)/XVI型胶原是一种跨膜半桥粒蛋白。此前，我们证明了BP180的胶原胞外域可以在靠近细胞膜的胞外非胶原性(NC)16A结构域内被切割并从细胞表面释放。在这里，我们报告了BP180的切割是由一种在上皮细胞中表达的膜相关金属蛋白酶介导的。金属蛋白酶组织抑制剂1(TIMP-1)，而不是TIMP-2，如合成的金属蛋白酶抑制剂KB-R8301，显著减少了切割。在融合后培养超过36h的上皮细胞中，抗BP180抗体显示半桥粒染色减少。首次观察到，在细胞培养中加入KB-R8301保留了这种染色。为了研究BP180的胞外切割对半染色体组分之间分子相互作用的影响，我们用胶原酶消化去除了BP180的胞外胶原区，但不包括NC16A结构域。有趣的是，这种胶原酶处理导致培养的人角质形成细胞中半染色体成分的部分分解。此外，针对被切割的胞外片段的单抗检测到该片段的独特的组织分布，这可能反映了切割过程与上皮组织的有丝分裂活动的关联。我们的观察表明，发生在NC16A结构域内的BP180的切割是由膜相关的金属蛋白水解酶介导的，并提示该切割可能参与了半染色体的拆解。
Bullous pemphigoid antigen 180 (BP180)/type XVII collagen is a transmembrane hemidesmosomal protein. Previously, we demonstrated that the collagenous ectodomain of BP180 can be cleaved within the extracellular non-collagenous (NC) 16A domain adjacent to the cell membrane and released from the cell surface. Here, we report that the BP180 cleavage is mediated by a membrane-associated metalloprotease expressed in epithelial cells. A tissue inhibitor of metalloprotease 1 (TIMP-1), but not TIMP-2, like the synthetic metalloprotease inhibitor KB-R8301, significantly reduced the cleavage. Within epithelial cells cultured for more than 36 h past confluency, antibodies to BP180 showed a reduced hemidesmosomal staining. Observed for the first time, addition of KB-R8301 to the cell culture preserved this staining. To examine the effect of the extracellular cleavage of BP180 on molecular interactions among hemidesmosomal components, we eliminated its collagenous extracellular portion, except for the NC16A domain, by collagenase digestion. Interestingly, this collagenase treatment caused partial disassembly of hemidesmosomal components in cultured human keratinocytes. Moreover, a monoclonal antibody specific for the cleaved extracellular fragment detected a unique tissue distribution of the fragment that might reflect an association of the cleavage process with the mitotic activity of epithelial tissues. Our observations demonstrate that the cleavage of BP180 occurring within the NC16A domain is mediated by a membrane-associated metalloprotease and suggest a possible involvement of the cleavage in hemidesmosomal disassembly.