Identification and characterization of human GRID2IP gene and rat Grid2ip gene in silico.

Formin-homology proteins are implicated in the cell polarity control through the assembly of specific actin structures. FMNL1/KW-13/FMNL, FMNL2/KIAA1902/FHOD2, FMNL3/KIAA2014, DAAM1, DAAM2, DIAPH1 and DIAPH2 are Formin-homology proteins with the FDD domain, while Fmn1, Fmn2, FHOD1 and Grid2ip/Delphilin are Formin-homology proteins without the FDD domain. Mouse Grid2ip links glutamate receptor delta2 subunit with actin cytoskeleton and various signaling molecules. Here, we identified and characterized human GRID2IP gene as well as rat Grid2ip gene by using bioinformatics. Human GRID2IP gene was identified within human genome sequence CTD-2195F21 (AC072052.6). Human GRID2IP gene, consisting of 21 exons, was mapped to human chromosome 7p22.1. Rat Grid2ip gene, consisting of 21 exons, was identified within rat genome sequence CH230-82F18 (AC126572.3). Human GRID2IP (1020 aa) showed 91.7% total-amino-acid identity with rat Grid2ip (1024 aa), and 92.7% total-amino-acid identity with mouse Grid2ip. Human GRID2IP protein was found to consist of PDZ domain (codon 94-166), GRCAH domain (codon 204-269), FH1 domain (codon 559-621), and FH2 domain (codon 640-1005). GRCAH domain identified in this study was conserved among mammalian GRID2IP orthologs and mammalian CIP98/KIAA1526 orthologs. This is the first report on comprehensive characterization of human GRID2IP gene as well as on identification of GRCAH domain.