Morgan R O, Fernández M P
Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Oviedo, Spain.
Cell Mol Life Sci. 1997 Jun;53(6):508-15. doi: 10.1007/s000180050064.
Annexins provide an exemplary model for studying the pattern and process of molecular evolution in multigene families. Their related gene structures, broad dispersal in eukaryotic genomes and abundant coding sequences permit a phylogenetic reconstruction of their genetic history. The emerging picture is one of prolific expansion by gene duplication to more than 27 paralogous subfamilies that have undergone steady sequence divergence, speciation and differential selection. Homologous recombination via the common tetrad of internal repeats has, nevertheless, strictly preserved this core structure for over 1200 million years, implying a basic functional role. The existence of multiple annexins with unique 5' coding and regulatory regions has facilitated their adaptation to the varying ontogenetic and cell-specific needs of diverse organisms. Computational and cladistic sequence analyses have permitted the determination of original gene duplication dates and mutation rates for the ten known vertebrate annexins. Molecular genetic and evolutionary studies of annexins can help to define their structure-function relationships elucidate their individual physiological roles and ultimately link them to hereditary phenotypes.
膜联蛋白为研究多基因家族中分子进化的模式和过程提供了一个典型模型。它们相关的基因结构、在真核生物基因组中的广泛分布以及丰富的编码序列，使得对其遗传历史进行系统发育重建成为可能。新出现的情况是，通过基因复制大量扩张形成了27个以上的旁系同源亚家族，这些亚家族经历了稳定的序列分歧、物种形成和差异选择。然而，通过内部重复序列的共同四分体进行的同源重组，在超过12亿年的时间里严格保留了这一核心结构，这意味着其具有基本的功能作用。具有独特5'编码和调控区域的多种膜联蛋白的存在，促进了它们适应不同生物体不同的个体发育和细胞特异性需求。计算和分支序列分析已确定了十种已知脊椎动物膜联蛋白的原始基因复制日期和突变率。膜联蛋白的分子遗传学和进化研究有助于确定它们的结构-功能关系，阐明它们各自的生理作用，并最终将它们与遗传表型联系起来。
