Zhang X S, Choi J H
Department of Biology and Life Sciences, Savannah State University, Savannah, GA 31404, USA.
J Mol Evol. 2001 Sep;53(3):214-24. doi: 10.1007/s002390010211.
Many genes for calmodulin-like domain protein kinases (CDPKs) have been identified in plants and Alveolate protists. To study the molecular evolution of the CDPK gene family, we performed a phylogenetic analysis of CDPK genomic sequences. Analysis of introns supports the phylogenetic analysis; CDPK genes with similar intron/exon structure are grouped together on the phylogenetic tree. Conserved introns support a monophyletic origin for plant CDPKs, CDPK-related kinases, and phosphoenolpyruvate carboxylase kinases. Plant CDPKs divide into two major branches. Plant CDPK genes on one branch share common intron positions with protist CDPK genes. The introns shared between protist and plant CDPKs presumably originated before the divergence of plants from Alveolates. Additionally, the calmodulin-like domains of protist CDPKs have intron positions in common with animal and fungal calmodulin genes. These results, together with the presence of a highly conserved phase zero intron located precisely at the beginning of the calmodulin-like domain, suggest that the ancestral CDPK gene could have originated from the fusion of protein kinase and calmodulin genes facilitated by recombination of ancient introns.
在植物和囊泡虫类原生生物中已鉴定出许多编码类钙调蛋白结构域蛋白激酶（CDPKs）的基因。为了研究CDPK基因家族的分子进化，我们对CDPK基因组序列进行了系统发育分析。内含子分析支持系统发育分析结果；具有相似内含子/外显子结构的CDPK基因在系统发育树上聚在一起。保守的内含子支持植物CDPKs、CDPK相关激酶和磷酸烯醇式丙酮酸羧化酶激酶起源于单系。植物CDPKs分为两个主要分支。一个分支上的植物CDPK基因与原生生物CDPK基因具有共同的内含子位置。原生生物和植物CDPKs之间共享的内含子可能起源于植物与囊泡虫类分化之前。此外，原生生物CDPKs的类钙调蛋白结构域与动物和真菌钙调蛋白基因具有共同的内含子位置。这些结果，连同在类钙调蛋白结构域起始位置精确存在的高度保守的0相位内含子，表明祖先CDPK基因可能起源于古代内含子重组促进的蛋白激酶和钙调蛋白基因的融合。
