Vogel J M, Morse R Y, Goodenow R S
Department of Genetics, University of California, Berkeley 94720.
Immunogenetics. 1989;29(1):33-43. doi: 10.1007/BF02341611.
A large number of H-2K and H-2D cDNA clones from a C3HfB/HeN spleen cDNA library were extensively characterized. All H-2Dk cDNAs were shown to exhibit the short form of exon 8, consistent with the presence of a single lariat branchpoint site within intron 7. Twenty-five H-2Kkm2 cDNAs were found to bear a short exon 8, whereas only two clones were shown to carry the longer form of this exon. In one of the H-2Kkm2 cDNAs, a novel pattern of H-2 splicing was identified, in which an extra 15 nucleotides, derived from the 3' end of intron 5, were inserted between the intact and unaltered exon 5 and exon 6 sequences. Resulting from the apparent use of a cryptic splice acceptor site in place of the canonical intron 5 site, this insertion is predicted to generate an in-frame insertion of five nonpolar amino acid residues within a highly polar region of the intracytoplasmic domain of the H-2K polypeptide. The features of this novel splice form served as the basis for predicting additional rare, alternative H-2 pre-mRNA splicing events that might produce functionally relevant microheterogeneity in the encoded H-2 gene products.
对来自C3HfB/HeN脾cDNA文库的大量H-2K和H-2D cDNA克隆进行了广泛表征。所有H-2Dk cDNA均显示出第8外显子的短形式，这与内含子7中存在单个套索分支点位点一致。发现25个H-2Kkm2 cDNA带有短的第8外显子，而只有两个克隆显示携带该外显子的较长形式。在一个H-2Kkm2 cDNA中，鉴定出一种新的H-2剪接模式，其中来自内含子5 3'端的额外15个核苷酸插入完整且未改变的第5外显子和第6外显子序列之间。由于明显使用了一个隐蔽的剪接受体位点来替代典型的内含子5位点，预计这种插入会在H-2K多肽胞质内结构域的高极性区域内产生五个非极性氨基酸残基的框内插入。这种新剪接形式的特征为预测其他罕见的、替代性的H-2前体mRNA剪接事件提供了基础，这些事件可能在编码的H-2基因产物中产生功能相关的微异质性。
