真核生物中支架蛋白家族(IQGAP family)的分子进化分析

支架蛋白家族(IQGAP family)广泛存在于真核生物中,在细胞的信号转导、骨架运动、细胞分裂的过程中都有着重要功能.研究分析IQGAP蛋白家族的分子进化,有助于深入全面地了解整个IQGAP蛋白家族在不同物种中功能.通过使用相关数据库,在35个真核生物物种中检索到了70个支架蛋白家族成员的序列信息,并对其进行了系统的分子进化研究.我们发现:支架蛋白家族基因广泛存在于后生动物(Metazoan)、真菌(Fungi)、变形虫界(Amoebozoa)以及其他一些真核生物中,提示支架蛋白存在于最后的真核生物的共同祖先(Last Eukaryotic Common Ancestor,LECA).系统发育分析表明脊椎动物的IQGAP蛋白和非脊椎动物中代表性IQGAP基因共享一个共同的祖先基因,单个的IQGAP祖先基因在早期脊椎动物中(在四足总纲和硬骨鱼纲的分离之前),发生了两次基因复制事件,导致现存的脊椎动物中3组IQGAP基因(IQGAP1,IQGAP2,IQGAP3)产生.

Phylogenetic Analysis of IQGAP Proteins in Eukaryotic Lineages

IQGAP family proteins present widely in eukaryotic lineages,and play important roles in the process of cell signal transduction,cell skeletal movement and cell division.Analysis of the molecular evolution of the IQGAP protein family is helpful in understanding the function of the whole IQGAP protein family in different species.Here we retrieved 70 members of the IQGAP family in 35 eukaryotic species,and carried a comprehensive phylogenetic analysis.We found that IQGAP family proteins exist in Metazoan,Fungi,Amoebozoa,as well as some other eukaryotes,suggesting that the common ancestor of IQGAP family present in the Last Eukaryotic Common the Ancestor (LECA).Phylogenetic analysis also showed that vertebrate IQGAP genes shared a common ancestral gene with several representative non vertebrate IQGAP genes,and a single ancestral IQGAP gene duplicated two times in early vertebrates (before tetrapoda and teleostei divergence),resulting in three groups of IQGAP genes (IQGAP1,IQGAP2,IQGAP3) formed in vertebrates.