Please use this identifier to cite or link to this item: https://doi.org/10.1152/physiolgenomics.00210.2005
Title: Comparative and evolutionary analysis of genes encoding small GTPases and their activating proteins in eukaryotic genomes
Authors: Jiang, S.-Y.
Ramachandran, S. 
Keywords: Divergence
Duplication
Gene expansion
Genome-wide analysis
Phylogeny
Issue Date: 23-Feb-2006
Citation: Jiang, S.-Y., Ramachandran, S. (2006-02-23). Comparative and evolutionary analysis of genes encoding small GTPases and their activating proteins in eukaryotic genomes. Physiological Genomics 24 (3) : 235-251. ScholarBank@NUS Repository. https://doi.org/10.1152/physiolgenomics.00210.2005
Abstract: Both small GTPase and its activating protein (GAP) superfamilies exist in various eukaryotes. The small GTPases regulate a wide variety of cellular processes by cycling between active GTP- and inactive GAP-bound conformations. The GAPs promote GTPase inactivation by stimulating the GTP hydrolysis. In this study, we identified 111 small GTPases and 85 GAPs in rice, 65 GAPs in Arabidopsis, 90 small GTPases in Drosophila melanogaster, and 35 GAPs in Saccharomyces cerevisiae by genome-wide analysis. We then analyzed and compared a total of 498 small GTPases and 422 GAPs from these four eukaryotic and human genomes. Both animals and yeast genomes contained five families of small GTPases and their GAPs. However, plants had only four of these five families because of a lack of the Ras and RasGAP genes. Small GTPases were conserved with common motifs, but GAPs exhibited higher and much more rapid divergence. On the basis of phylogenetic analysis of all small GTPases and GAPs in five eukaryotic organisms, we estimated that their ancestors had small sizes of small GTPases and GAPs and their large-scale expansions occurred after the divergence from their ancestors. Further investigation showed that genome duplications represented the major mechanism for such expansions. Nonsynonymous substitutions per site (Ka) and synonymous substitutions per site (Ks) analyses showed that most of the divergence due to a positive selection occurred in common ancestors, suggesting a major functional divergence in an ancient era. Copyright © 2006 the American Physiological Society.
Source Title: Physiological Genomics
URI: http://scholarbank.nus.edu.sg/handle/10635/115651
ISSN: 10948341
DOI: 10.1152/physiolgenomics.00210.2005
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

SCOPUSTM   
Citations

59
checked on Jun 16, 2021

WEB OF SCIENCETM
Citations

61
checked on Jun 7, 2021

Page view(s)

112
checked on Jun 19, 2021

Google ScholarTM

Check

Altmetric


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.