人类ADAM家族成员ADAM23a的克隆

Cloning of the Human ADAM23a

应用与ADAM家族成员高度同源、来自人胎脑的EST(expressedsequencetag)为探针 ,从人 2 2周胎脑cDNA文库中分离到 3.0kb长的cDNA片段 ,除了C末端缺少 91nt外 ,与ADAM 2 3同源性达 10 0 % ,编码的蛋白未能形成明显的跨膜区 ,定名为ADAM2 3a .在检测中发现 ,该基因与ADAM 2 3的C末端相同位置的氨基酸序列中 ,分析其金属蛋白酶功能域 (metalloproteinasedomain) ,不含有结合Zn的活性位点 ,去整联蛋白功能域(disintegrindomain)与ADAM部分成员具有同源性 .在人 16种组织的Northernblot检测 ,ADAM 2 3a仅在心脏和脑中表达 .由于 2种cDNA从不同发育时期的胎脑及脑中分离得到 ,有可能是在发育过程受到了调节 ,可能通过去整联蛋白功能域与脑和心脏中的整联蛋白 (integrin)

An EST (expressed sequence tag) from human fetal brain homologous to ADAM was used as a probe to screen a human fetal brain (22 weeks old) cDNA library. A cDNA fragment termed ADAM23a was isolated which showed 100% homology to human ADAM23 except for Lacking 91 nt at the C terminal, resulting in forming no obvious TM domain.A zinc binding motif, which was critical for proteinase activity, was disrupted in the metalloproteinase like domain. Disintegrin domain was similar to some other ADAM members. Northern blot analysis revealed that ADAM23a was expressed in heart and brain. The two different cDNAs could be regulated during brain development because they were isolated from different stages of human brain.