Journal Article


Nora Khaldi
Denis C. Shields
Jens E Nielsen
Nicolas Alendé



humans evolution molecular proteome isoelectric point sequence alignment molecular sequence data chemistry amino acid sequence indel mutation animals genetics

Evolution of the isoelectric point of mammalian proteins as a consequence of indels and adaptive evolution. (2010)

Abstract 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.
Collections Ireland -> University College Dublin -> PubMed

Full list of authors on original publication

Nora Khaldi, Denis C. Shields, Jens E Nielsen, Nicolas Alendé

Experts in our system

Denis C. Shields
University College Dublin
Total Publications: 118
Jens Erik Nielsen
University College Dublin
Total Publications: 27