Computational identification and analysis of immune-associated nucleotide gene family in Arabidopsis thaliana.

GTP-binding proteins represent a ubiquitous regulatory mechanism in controlling growth and development in eukaryotes under normal and stress conditions. The IAN/GIMAP proteins belong to a novel family of functionally uncharacterized GTP-binding proteins expressed in both plant and vertebrate cells during anti-pathogenic responses. To gain novel insights into their roles in plants, we did genome-wide analysis of the IAN/GIMAP gene family. We identified 13 Arabidopsis IAN/GIMAP genes, which share similar gene structures and mostly reside in a tandem cluster on chromosomes. Sequence comparison reveals that these genes encode 26-52 kDa proteins with one GTP-binding domain and a conserved box unique to the family. Phylogenetic analysis suggests that the IAN/GIMAP genes of angiosperms and vertebrates may have evolved by independent gene duplication events. GENEVESTIGATOR sources were mined for comprehensive and comparative Arabidopsis IAN/GIMAP gene family expression analysis. These data reveal that IAN/GIMAPs exhibit diverse expression patterns during development and in response to external stimuli, indicating that these paralogous genes are likely involved in complex biological processes in Arabidopsis. Our present findings provide a basis for elucidating the novel GTPase family protein-mediated regulatory mechanisms in the future.