EXPRESSION, STRUCTURE AND FUNCTION OF LORICRIN, A MAJOR CELL ENVELOPE PROTEIN

细胞膜由一层厚厚的高度不溶的蛋白质组成。 在玉米地表皮细胞质膜的内侧 其他复层鳞状上皮细胞。几种可能的蛋白质 组件，到目前为止还没有一个组件被证明是主要组件，因为 氨基酸组成、信使核糖核酸水平或 表达的蛋白质。我们最近发现了一种新的蛋白质，称为 三氯氰菊酯，符合主要成分的所有要求 细胞包膜上的。洛里克林克隆最初是在一只小鼠身上发现的 表皮，现在更详细地说，来自人类的表皮。洛丽克林是 富含甘氨酸的蛋白质，含有高度灵活的甘氨酸环 Motif。它们通过异二肽N-epsilon在细胞膜中交联- (谷氨酰基)赖氨酸键。通过使用Northern槽印迹 技术和数学模型估计，我们已经确定 氯氰菊酯占成熟细胞总质量的70%-80% 小鼠和人的表皮的包膜，而其他成分 比这还少。我们假设细胞包膜首先是组装好的 通过添加某些可溶性蛋白质，如总蛋白，胱抑素A， 等，然后大量随后沉积氯氰菊酯。

The cell envelope constitutes a thick layer of highly insoluble protein on the inside of the plasma membrane of cornfield epidermal cells and of other stratified squamous epithelial cells. Of several putative protein components, none has hitherto proven to be a major component because of major differences in amino acid composition, levels of mRNA or of expressed protein. We have recently identified a new protein, termed loricrin, that fulfills all of the requirements of a major constituent of the cell envelope. Loricrin clones were first identified in a mouse epidermis, and now in more detail, from human epidermis. Loricrins are glycine-rich proteins that contain the highly flexible glycine loop motif. They are crosslinked in cell envelopes by isodipeptide N epsilon- (gamma-glutamyl)lysine bonds. By use of Northern slot blotting techniques and mathematical modeling estimates, we have determined that loricrin constitutes up to 70-80% of the total mass of mature cell envelopes of mouse and human epidermis, while other components are much less than this. We postulate that the cell envelope is first assembled by addition of certain soluble proteins such as involucrin, cystatin A, etc., followed by massive subsequent deposition of loricrin.