Tsutsui K, Maeda Y, Tsutsui K, Seki S, Tokunaga A
Department of Molecular Biology, Institute of Cellular and Molecular Biology, Okayama University Medical School, Shikata-cho, Japan.
Biochem Biophys Res Commun. 1997 Jul 9;236(1):178-83. doi: 10.1006/bbrc.1997.6927.
Amphiphysin, an SH3-domain containing protein concentrated in nerve terminals, is believed to be involved in the synaptic vesicle recycling. We have cloned cDNAs of a novel isoform of amphiphysin (amphiphysin II) by exploiting sequence information for homologous ESTs deposited in databases. At least 9 different subtypes of the isoform with 50-60% amino acid identity to the human amphiphysin were identified by a conventional library screening and PCR amplification of cDNA libraries. Each subtype probably represents a splice variant of a single gene transcript. Analysis of mRNA expression in various tissues by RT-PCR showed that the isoform is ubiquitously distributed. The expression spectrum of the isoform subtypes, however, is significantly different in several tissues examined, suggesting that they are involved in the regulation of endocytic processes that are unique to each cell type.
发动蛋白是一种含有SH3结构域的蛋白质，集中在神经末梢，被认为参与突触小泡循环。我们利用数据库中同源EST的序列信息克隆了发动蛋白的一种新亚型（发动蛋白II）的cDNA。通过常规文库筛选和cDNA文库的PCR扩增，鉴定出至少9种不同亚型的该异构体，其与人类发动蛋白的氨基酸同一性为50-60%。每个亚型可能代表单个基因转录本的剪接变体。通过RT-PCR分析各种组织中的mRNA表达表明，该异构体广泛分布。然而，在几个检测的组织中，该异构体亚型的表达谱有显著差异，表明它们参与了每种细胞类型特有的内吞过程的调控。
