Envoplakin, a novel precursor of the cornified envelope that has homology to desmoplakin.
Envoplakin, a novel precursor of the cornified envelope that has homology to desmoplakin.
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DOI：
10.1083/jcb.134.3.715
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发表时间：
1996-08
期刊：
影响因子：
--
通讯作者：
Watt FM
中科院分区：
文献类型：
--
作者：
Ruhrberg C;Hajibagheri MA;Simon M;Dooley TP;Watt FM
皮质包膜是沉积在表皮最外层角质形成细胞质膜下的一层转氨酶交联蛋白。我们提出的序列的corpendum信封前体，蛋白质的表观分子量为210 kD。210-kD蛋白质由单拷贝基因转录的6.5- kb mRNA翻译而来。在培养的人角质形成细胞悬浮诱导的终末分化过程中，mRNA上调。与其他包膜前体一样，210 kD蛋白在培养的角质形成细胞中激活转氨酶后变得不溶于SDS和β-巯基乙醇。该蛋白在角化和非角化复层鳞状上皮中表达，而在单纯上皮和非上皮细胞中不表达。免疫荧光染色显示，在表皮角质形成细胞，在体内和在文化中，蛋白上调终末分化和部分共定位与桥粒蛋白。免疫金EM证实了共定位的210 kD蛋白和桥粒斑蛋白在桥粒和角蛋白丝在整个分化层的表皮。序列分析表明，210-kD蛋白与角蛋白结合蛋白桥斑蛋白、大疱性类天疱疮抗原1和果胶同源。这些数据表明，210-kD蛋白质可能连接的皮质包膜的桥粒和角蛋白丝。我们建议将210-kD蛋白命名为“envoplakin”。"
The cornified envelope is a layer of transglutaminase cross-linked protein that is deposited under the plasma membrane of keratinocytes in the outermost layers of the epidermis. We present the sequence of one of the cornified envelope precursors, a protein with an apparent molecular mass of 210 kD. The 210-kD protein is translated from a 6.5- kb mRNA that is transcribed from a single copy gene. The mRNA was upregulated during suspension-induced terminal differentiation of cultured human keratinocytes. Like other envelope precursors, the 210- kD protein became insoluble in SDS and beta-mercaptoethanol on activation of transglutaminases in cultured keratinocytes. The protein was expressed in keratinizing and nonkeratinizing stratified squamous epithelia, but not in simple epithelia or nonepithelial cells. Immunofluorescence staining showed that in epidermal keratinocytes, both in vivo and in culture, the protein was upregulated during terminal differentiation and partially colocalized with desmosomal proteins. Immunogold EM confirmed the colocalization of the 210-kD protein and desmoplakin at desmosomes and on keratin filaments throughout the differentiated layers of the epidermis. Sequence analysis showed that the 210-kD protein is homologous to the keratin- binding proteins desmoplakin, bullous pemphigoid antigen 1, and plectin. These data suggest that the 210-kD protein may link the cornified envelope to desmosomes and keratin filaments. We propose that the 210-kD protein be named "envoplakin."