Abstract：
The LIM and SH3 domain protein (lasp) family, the smallest proteins in the nebulin superfamily, consists of vertebrate lasp-1 expressed in various non-muscle tissues, vertebrate lasp-2 expressed in the brain and cardiac muscle, and invertebrate lasp whose functions have been analyzed in Ascidiacea and Insecta. Gene evolution of the lasp family proteins was investigated by multiple alignments, comparison of gene structure, and synteny analyses in eukaryotes in which mRNA expression was confirmed. All invertebrates analyzed in this study belonging to the clade Filasterea, with the exception of Placozoa, have at least one lasp gene. The minimal actin-binding region (LIM domain and first nebulin repeat) and SH3 domain detected in vertebrate lasp-2 were found to be conserved among the lasp family proteins, and we showed that nematode lasp has actin-binding activity. The linker sequences vary among invertebrate lasp proteins, implying that the lasp family proteins have universal and diverse functions. Gene structures and syntenic analyses suggest that a gene fragment encoding two nebulin repeats and a linker emerged in Filasterea or Holozoa, and the first lasp gene was generated following combination of three gene fragments encoding the LIM domain, two nebulin repeats with a linker, and the SH3 domain.
摘要：
LIM和SH3结构域蛋白（lasp）家族，星云超家族中最小的蛋白质，由在各种非肌肉组织中表达的脊椎动物搭扣-1组成，脊椎动物lasp-2在大脑和心肌中表达，和无脊椎动物扣，其功能已在Ascidiacea和Insecta中进行了分析。通过多次比对研究了lasp家族蛋白的基因进化，基因结构比较，和真核生物中mRNA表达得到证实的同系性分析。在这项研究中分析的所有无脊椎动物都属于Filasterea进化枝，除了Placozoa,至少有一个搭扣基因.发现在脊椎动物lasp-2中检测到的最小肌动蛋白结合区（LIM结构域和第一个星云蛋白重复序列）和SH3结构域在lasp家族蛋白中保守，我们证明线虫刺骨具有肌动蛋白结合活性。接头序列在无脊椎动物搭扣蛋白中有所不同，这意味着lasp家族蛋白具有普遍性和多样性的功能。基因结构和合成分析表明，在Filasterea或Holozoa中出现了编码两个星状蛋白重复序列和一个接头的基因片段，第一个lasp基因是在三个编码LIM结构域的基因片段组合后产生的，两个带有接头的星云重复，和SH3域。
