RRC ID 36804
Author Jiang SY, Ramachandran S.
Title Comparative and evolutionary analysis of genes encoding small GTPases and their activating proteins in eukaryotic genomes.
Journal Physiol Genomics
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 cerevisiaeby 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.
Volume 24(3)
Pages 235-51
Published 2006-2-14
DOI 10.1152/physiolgenomics.00210.2005
PII 00210.2005
PMID 16332933
MeSH Amino Acid Motifs Amino Acid Sequence Animals Arabidopsis / genetics Drosophila melanogaster / genetics Evolution, Molecular* GTPase-Activating Proteins / genetics* GTPase-Activating Proteins / metabolism Genes, Duplicate Genome Humans Molecular Sequence Data Monomeric GTP-Binding Proteins / genetics* Monomeric GTP-Binding Proteins / metabolism Phylogeny Saccharomyces cerevisiae / genetics Sequence Alignment Sequence Analysis ras GTPase-Activating Proteins / genetics
IF 2.749
Times Cited 59
Rice Oryzabase