Kastern W
Gene. 1985;34(2-3):227-33. doi: 10.1016/0378-1119(85)90131-3.
A cDNA clone that shares considerable homology with mRNA for class-I major-histocompatibility (MHC) antigens has been isolated from a cDNA library constructed from an insulin-secreting tumor of the NEDH rat (RIN). Although there is very strong homology between the third extracellular domain of this gene, and other class-I antigen genes, a stop codon was noticed at the junction between the external and transmembrane regions of its protein. Thus, this gene codes for a truncated class-I antigen that lacks both transmembrane and cytoplasmic domains but has hydrophilic amino acids towards its C-terminus and therefore resembles a soluble protein. This gene was found to be transcribed at significant levels in the rat testis and an insulin-secreting tumor, but transcription was negligible in liver and kidney. The partial nucleotide sequence of this gene in a Wistar rat genomic clone indicates that the cDNA clone is represented in the rat genome complete with premature termination codon, thus eliminating the possibility of artifactual origins for the clone.
从一只NEDH大鼠（RIN）胰岛素分泌肿瘤构建的cDNA文库中，分离出了一个与I类主要组织相容性（MHC）抗原的mRNA具有相当同源性的cDNA克隆。尽管该基因的第三个细胞外结构域与其他I类抗原基因之间存在很强的同源性，但在其蛋白质的细胞外和跨膜区域交界处发现了一个终止密码子。因此，该基因编码一种截短的I类抗原，它既缺乏跨膜结构域也缺乏细胞质结构域，但在其C末端有亲水性氨基酸，因此类似于一种可溶性蛋白质。该基因在大鼠睾丸和胰岛素分泌肿瘤中大量转录，但在肝脏和肾脏中的转录可以忽略不计。Wistar大鼠基因组克隆中该基因的部分核苷酸序列表明，该cDNA克隆在大鼠基因组中存在，且带有提前终止密码子，从而排除了该克隆人为起源的可能性。
