Del Porto P, Bruno L, Mattei M G, von Boehmer H, Saint-Ruf C
Unité Institut National de la Santé et de la Recherche Médicale 373, Institut Necker, Paris, France.
Proc Natl Acad Sci U S A. 1995 Dec 19;92(26):12105-9. doi: 10.1073/pnas.92.26.12105.
In immature T cells the T-cell receptor (TCR) beta-chain gene is rearranged and expressed before the TCR alpha-chain gene. At this stage TCR beta chain can form disulfide-linked heterodimers with the pre-T-cell receptor alpha chain (pTalpha). Using the recently isolated murine pTalpha cDNA as a probe, we have isolated the human pTalpha cDNA. The complete nucleotide sequence predicts a mature protein of 282 aa consisting of an extracellular immunoglobulin-like domain, a connecting peptide, a transmembrane region, and a long cytoplasmic tail. Amino acid sequence comparison of human pTalpha with the mouse pTalpha molecule reveals high sequence homology in the extracellular as well as the transmembrane region. In contrast, the cytoplasmic region differs in amino acid composition and in length from the murine homologue. The human pTalpha gene is expressed in immature but not mature T cells and is located at the p21.2-p12 region of the short arm of chromosome 6.
在未成熟T细胞中，T细胞受体（TCR）β链基因在TCRα链基因之前进行重排和表达。在此阶段，TCRβ链可与前T细胞受体α链（pTα）形成二硫键连接的异二聚体。利用最近分离的小鼠pTα cDNA作为探针，我们分离出了人pTα cDNA。完整的核苷酸序列预测了一个由282个氨基酸组成的成熟蛋白，该蛋白由一个细胞外免疫球蛋白样结构域、一个连接肽、一个跨膜区域和一个长的胞质尾组成。人pTα与小鼠pTα分子的氨基酸序列比较显示，在细胞外以及跨膜区域存在高度的序列同源性。相比之下，胞质区域在氨基酸组成和长度上与小鼠同源物不同。人pTα基因在未成熟而非成熟T细胞中表达，位于6号染色体短臂的p21.2-p12区域。
