Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, Lavrentyev ave,, 10, Novosibirsk, Russia.
BMC Evol Biol. 2011 Jul 28;11:224. doi: 10.1186/1471-2148-11-224.
The passage through the cell cycle is controlled by complexes of cyclins, the regulatory units, with cyclin-dependent kinases, the catalytic units. It is also known that cyclins form several families, which differ considerably in primary structure from one eukaryotic organism to another. Despite these lines of evidence, the relationship between the evolution of cyclins and their function is an open issue. Here we present the results of our study on the molecular evolution of A-, B-, D-, E-type cyclin proteins in animals and fungi.
We constructed phylogenetic trees for these proteins, their ancestral sequences and analyzed patterns of amino acid replacements. The analysis of infrequently fixed atypical amino acid replacements in cyclins evidenced that accelerated evolution proceeded predominantly during paralog duplication or after it in animals and fungi and that it was related to aromorphic changes in animals. It was shown also that evolutionary flexibility of cyclin function may be provided by consequential reorganization of regions on protein surface remote from CDK binding sites in animal and fungal cyclins and by functional differentiation of paralogous cyclins formed in animal evolution.
The results suggested that changes in the number and/or nature of cyclin-binding proteins may underlie the evolutionary role of the alterations in the molecular structure of cyclins and their involvement in diverse molecular-genetic events.
细胞周期的进程由细胞周期蛋白（调节单位）与细胞周期蛋白依赖性激酶（催化单位）复合物控制。此外，人们还知道细胞周期蛋白形成了几个家族，这些家族在一级结构上与不同的真核生物有很大的不同。尽管有这些证据，但细胞周期蛋白的进化与其功能之间的关系仍然是一个悬而未决的问题。在这里，我们展示了我们对动物和真菌中 A、B、D、E 型细胞周期蛋白蛋白的分子进化的研究结果。
我们为这些蛋白质及其祖先序列构建了系统发育树，并分析了氨基酸替换模式。对细胞周期蛋白中罕见固定的非典型氨基酸替换的分析表明，在动物和真菌中，加速进化主要发生在旁系同源物重复或之后，并且与动物中的芳香变化有关。还表明，动物和真菌中细胞周期蛋白功能的进化灵活性可能是由蛋白质表面远离 CDK 结合位点的区域的继发重组提供的，并且是由动物进化中形成的旁系同源细胞周期蛋白的功能分化提供的。
研究结果表明，细胞周期蛋白结合蛋白的数量和/或性质的变化可能是细胞周期蛋白分子结构改变的进化作用的基础，并且可能参与了各种分子遗传事件。
