Zhou Y, Chaplin D D
Howard Hughes Medical Institute, Washington University School of Medicine, St. Louis, MO 63110.
Proc Natl Acad Sci U S A. 1993 Oct 15;90(20):9470-4. doi: 10.1073/pnas.90.20.9470.
A gene designated S has been identified in the class I region of the human major histocompatibility complex. The S gene is located 160 kb telomeric of HLA-C. It is expressed at high levels as 2.2-kb and 2.6-kb mRNAs in human skin. No homologous transcripts were detected in other tissues including placenta, liver, spleen, thymus, and brain. In situ hybridization showed that S gene expression was restricted to the differentiating keratinocytes in the granular layer of the epidermis. The predicted amino acid sequence of the S protein was remarkable for its high content of serine, glycine, and proline. There were significant similarities with the amino acid sequences of loricrin, keratin 1, and keratin 10, all major components of the granular-cell layer. The selective expression of the S gene in the granular-cell layer in the epidermis suggests a role in the developmental program of differentiating keratinocytes. Furthermore, in light of the recognized association of psoriasis vulgaris, a disorder of keratinocyte proliferation, with alleles of HLA-C, this gene may contribute primarily to the pathogenesis of this common disorder.
在人类主要组织相容性复合体的I类区域中已鉴定出一个名为S的基因。S基因位于HLA - C端粒方向160 kb处。它在人类皮肤中以2.2 kb和2.6 kb的mRNA高水平表达。在包括胎盘、肝脏、脾脏、胸腺和大脑在内的其他组织中未检测到同源转录本。原位杂交显示，S基因表达局限于表皮颗粒层中正在分化的角质形成细胞。S蛋白的预测氨基酸序列以其高含量的丝氨酸、甘氨酸和脯氨酸而显著。它与兜甲蛋白、角蛋白1和角蛋白10的氨基酸序列有显著相似性，这些都是颗粒细胞层的主要成分。S基因在表皮颗粒细胞层中的选择性表达表明其在分化角质形成细胞的发育程序中起作用。此外，鉴于寻常型银屑病（一种角质形成细胞增殖紊乱疾病）与HLA - C等位基因的公认关联，该基因可能主要促成这种常见疾病的发病机制。
