Simon M, Green H
Cell. 1984 Apr;36(4):827-34. doi: 10.1016/0092-8674(84)90032-1.
Cultured keratinocytes, like those in natural squamous epithelia, form submembranous protein envelopes cross-linked by cellular transglutaminase. During the cross-linking, the cytosolic protein involucrin becomes incorporated into the envelope and can no longer be extracted by detergents. We show here that when transglutaminase is activated in cultured keratinocytes, at least six other proteins also become nonextractable. In contrast to involucrin, these proteins are associated with membranes. Two of the proteins (210 and 195 kd) are differentiated products specific to the keratinocyte; like involucrin, they are absent from small keratinocytes and fibroblasts, but appear in larger keratinocytes during the course of their terminal differentiation. The other proteins that become nonextractable cannot be destined exclusively for envelope formation since they are also present in fibroblasts. Transglutaminase is used by the mature (large) keratinocyte to make a detergent-resistant envelope from what appears to be a mixture of differentiation-specific and nonspecific proteins, both membrane-bound and cytosolic.
培养的角质形成细胞，如同天然鳞状上皮中的细胞一样，会形成由细胞转谷氨酰胺酶交联的膜下蛋白包膜。在交联过程中，胞质蛋白内披蛋白会掺入包膜中，并且不再能被去污剂提取。我们在此表明，当培养的角质形成细胞中转谷氨酰胺酶被激活时，至少还有其他六种蛋白质也变得不可提取。与内披蛋白不同，这些蛋白质与膜相关。其中两种蛋白质（210和195千道尔顿）是角质形成细胞特有的分化产物；与内披蛋白一样，它们在小角质形成细胞和成纤维细胞中不存在，但在其终末分化过程中出现在较大的角质形成细胞中。其他变得不可提取的蛋白质不可能专门用于包膜形成，因为它们也存在于成纤维细胞中。成熟（大）角质形成细胞利用转谷氨酰胺酶，从似乎是分化特异性和非特异性蛋白质（包括膜结合蛋白和胞质蛋白）的混合物中制造出抗去污剂的包膜。
