Polakowska R, Herting E, Goldsmith L A
University of Rochester Medical Center, Department of Dermatology, New York 14642.
J Invest Dermatol. 1991 Feb;96(2):285-8. doi: 10.1111/1523-1747.ep12464554.
Keratinocytes of stratified epithelia, including the epidermis, express two distinct forms of transglutaminase, type I and type II. Type I transglutaminase activity is responsible for cell envelope formation in terminally differentiating cultured keratinocytes. Transglutaminase enzymatic activity has been associated with several proteins that are differentially expressed in vivo and in vitro. To elucidate the relationship between the epidermally expressed transglutaminases, cDNA for type I transglutaminase was cloned from a human high-calcium keratinocyte lambda gt11 library. cDNA fragments, generated by PCR primed with a mixture of oligonucleotides coding for five invariant amino acids in the active site, were used as a screening probe. Based on the sequence analysis of 1653 nt contained in the lambda 1-126a clone and on the pattern of expression of a complementary approximately 3-kb transcript, we report cloning of the epidermal type I transglutaminase gene. The expression of this gene is regulated by calcium ions and retinoic acid in cultured human keratinocytes. There are highly conserved regions near the active site cysteine residues that may be important for the enzyme's specialized functions.
包括表皮在内的复层上皮角质形成细胞表达两种不同形式的转谷氨酰胺酶，即I型和II型。I型转谷氨酰胺酶活性负责终末分化的培养角质形成细胞中细胞包膜的形成。转谷氨酰胺酶的酶活性与体内和体外差异表达的几种蛋白质有关。为了阐明表皮表达的转谷氨酰胺酶之间的关系，从人高钙角质形成细胞λgt11文库中克隆了I型转谷氨酰胺酶的cDNA。用编码活性位点五个不变氨基酸的寡核苷酸混合物进行PCR产生的cDNA片段用作筛选探针。基于λ1-126a克隆中包含的1653 nt的序列分析以及互补的约3 kb转录物的表达模式，我们报道了表皮I型转谷氨酰胺酶基因的克隆。该基因的表达在培养的人角质形成细胞中受钙离子和视黄酸调节。在活性位点半胱氨酸残基附近有高度保守的区域，这可能对该酶的特殊功能很重要。
