Evolution of the isoelectric point of mammalian proteins as a consequence of indels and adaptive evolution
Evolution of the isoelectric point of mammalian proteins as a consequence of indels and adaptive evolution
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DOI：
10.1002/prot.22990
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发表时间：
2011-05-01
影响因子：
2.9
通讯作者：
Khaldi, Nora
中科院分区：
文献类型：
--
作者：
Alende, Nicolas;Nielsen, Jens E.;Khaldi, Nora
虽然原核生物蛋白质的等电点的重要变化，主要是由于适应环境pH值，已被广泛报道，这些研究还没有涵盖哺乳动物蛋白质，其中pH值的变化可能与亚细胞或组织区室化的变化。我们探讨了13种哺乳动物的蛋白质组的等电点。我们检测到的蛋白质已经改变了他们的pI最13种哺乳动物中，并调查这些差异是否反映了适应不同的条件下的orthopathy蛋白。我们发现，表现出高等电点变化的蛋白质富含某些GO术语，包括免疫防御和线粒体蛋白。我们发现，在pI之间的orthopathic蛋白质的转变是不是强烈相关的蛋白质进化的整体速度，也与蛋白质长度。我们的研究结果表明，插入/缺失的pI的移动背后的主要原因。然而，对于某些蛋白质，我们发现选择通过氨基酸替换改变蛋白质的pI的证据。最后，我们认为，在PI的变化可能涉及到额外的活动，如新的相互作用的合作伙伴，在一个直系同源物，而不是其他的增益，并可能涉及到哺乳动物之间的功能差异。Proteins 2011; 79：1635-1648. (C)2011 Wiley-Liss，Inc.
Although important shifts in the isoelectric point of prokaryotic proteins, mainly due to adaptation to environmental pH, have been widely reported, such studies have not covered mammalian proteins, where pH changes may relate to changes in subcellular or tissue compartmentalization. We explored the isoelectric point of the proteome of 13 mammalian species. We detected proteins that have shifted their pI the most among 13 mammalian species, and investigated if these differences reflect adaptations of the orthologous proteins to different conditions. We find that proteins exhibiting a high isoelectric point change are enriched in certain GO terms, including immune defense, and mitochondrial proteins. We show that the shift in pI between orthologous proteins is not strongly associated with the overall rate of protein evolution, nor with protein length. Our results reveal that insertions/deletions are the main reason behind the shift of pI. However, for some proteins we find evidence of selection shifting the pI of the protein through amino acid replacement. Finally, we argue that shifts in pI might relate to the gain of additional activities, such as new interacting partners, in one ortholog as opposed to the other, and may potentially relate to functional differences between mammals. Proteins 2011; 79: 1635-1648. (C) 2011 Wiley-Liss, Inc.