Durkin M E, Gautam M, Loechel F, Sanes J R, Merlie J P, Albrechtsen R, Wewer U M
Laboratory of Molecular Pathology, University Institute of Pathological Anatomy, 2100 Copenhagen, Denmark.
J Biol Chem. 1996 Jun 7;271(23):13407-16. doi: 10.1074/jbc.271.23.13407.
We have determined the structural organization of the human and mouse genes that encode the laminin beta2 chain (s-laminin), an essential component of the basement membranes of the neuromuscular synapse and the kidney glomerulus. The human and mouse genes have a nearly identical exon-intron organization and are the smallest laminin chain genes characterized to date, due to the unusually small size of their introns. The laminin beta2 chain genes of both species consist of 33 exons that span </=12 kilobase pairs of genomic DNA. The exon-intron pattern of the laminin beta2 chain gene is also highly similar to that of the human genes encoding the homologous laminin beta1 and beta3 chains. The putative promoter regions of the human and mouse laminin beta2 chain genes have features characteristic of the promoters of genes that have a limited tissue expression. Considerable conservation of the intron sequences of the mouse and human genes was observed. The first intron of the human gene, located 1 base pair upstream of the translation start codon, contains a non-consensus 5' splice site. This intron was shown to be inefficiently spliced in humans, suggesting that post-transcriptional mechanisms may be involved in the regulation of laminin beta2 chain gene expression.
我们已经确定了编码层粘连蛋白β2链（s-层粘连蛋白）的人类和小鼠基因的结构组织，该蛋白是神经肌肉突触和肾小球基底膜的重要组成部分。人类和小鼠基因具有几乎相同的外显子-内含子组织，并且由于其内含子异常小，是迄今为止已鉴定的最小的层粘连蛋白链基因。这两个物种的层粘连蛋白β2链基因均由33个外显子组成，跨越≤12千碱基对的基因组DNA。层粘连蛋白β2链基因的外显子-内含子模式也与编码同源层粘连蛋白β1和β3链的人类基因高度相似。人类和小鼠层粘连蛋白β2链基因的推定启动子区域具有组织表达受限的基因启动子的特征。观察到小鼠和人类基因的内含子序列有相当程度的保守性。人类基因的第一个内含子位于翻译起始密码子上游1个碱基对处，包含一个非共识5'剪接位点。该内含子在人类中显示出低效剪接，这表明转录后机制可能参与层粘连蛋白β2链基因表达的调控。
