Molecular evolution of aerobic energy metabolism in primates
Molecular evolution of aerobic energy metabolism in primates
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DOI：
10.1006/mpev.2000.0890
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发表时间：
2001-01-01
影响因子：
4.1
通讯作者：
Goodman, M
中科院分区：
文献类型：
--
作者：
Grossman, LI;Schmidt, TR;Goodman, M
作为我们在DNA水平上重建人类进化的目标的一部分，我们一直在研究有氧能量代谢的生化机制的变化。我们发现，两个电子转移复合体--复合体III和复合体IV的蛋白质亚单位，以及连接它们的蛋白质载体细胞色素c，在类人族谱系中都经历了一段快速的蛋白质进化时期，最终导致了人类。事实上，细胞色素C氧化酶(COX；Complex RV)的亚单位Tv提供了所研究的任何蛋白质的积极选择变化的最佳例子之一。在4,000万至1,800万年前，卡他龙祖先的TV亚基进化速度加快，然后在原始人后代中减速，这种速率变化模式表明，适应性变化的积极选择，随后是针对进一步变化的净化选择。除了清楚的证据表明细胞色素c和复合体III(例如，细胞色素c(1))和复合体IV(例如，COX2和COX4)的亚基发生了适应性进化外，在导致人类的谱系中，这两个复合体的其他亚基也出现了适度的加速。此外，COX亚基的收缩肌肉特异性亚基在人类祖先中成为假基因，但在非类人灵长类动物中似乎是一个功能基因。有氧能量复合体的这些变化与高级灵长类动物出现期间依赖能量的新皮质的扩张相一致。发现分子进化分析提出的生化适应将是一个令人兴奋的挑战。(C)2000年学术出版社。
As part of our goal to reconstruct human evolution at the DNA level, we have been examining changes in the biochemical machinery for aerobic energy metabolism. We find that protein subunits of two of the electron transfer complexes, complex III and complex IV, and cytochrome c, the protein carrier that connects them, have all undergone a period of rapid protein evolution in the anthropoid lineage that ultimately led to humans. Indeed, subunit TV of cytochrome c oxidase (COX; complex rv) provides one of the best examples of positively selected changes of any protein studied. The rate of subunit TV evolution accelerated in our catarrhine ancestors in the period between 40 to 18 million years ago and then decelerated in the descendant hominid lineages, a pattern of rate changes indicative of positive selection of adaptive changes followed by purifying selection acting against further changes. Besides clear evidence that adaptive evolution occurred for cytochrome c and subunits of complexes III (e.g,, cytochrome c(1)) and IV (e.g., COX2 and COX4), modest rate accelerations in the lineage that led to humans are seen for other subunits of both complexes. In addition the contractile muscle-specific isoform of COX subunit VIII became a pseudogene in an anthropoid ancestor of humans but appears to be a functional gene in the nonanthropoid primates. These changes in the aerobic energy complexes coincide with the expansion of the energy-dependent neocortex during the emergence of the higher primates. Discovering the biochemical adaptations suggested by molecular evolutionary analysis will be an exciting challenge. (C) 2000 Academic Press.