Rho GDP Dissociation Inhibitor Alpha (ARHGDIa)

Aplysia Ras-related homologs (ARHs), also called Rho genes, belong to the RAS gene superfamily encoding small guanine nucleotide exchange (GTP/GDP) factors. The ARH proteins may be kept in the inactive, GDP-bound state by interaction with GDP dissociation inhibitors, such as ARHGDIA. ARHGDIA corresponded to a protein in the keratinocyte 2-dimensional-gel protein database known as IEF (isoelectric focusing) 8118. By 2-dimensional gel electrophoresis, the predicted 204-amino acid protein had a pI of 4.74 and migrated at 29 kD. The amino acid sequences of human and bovine ARHGDIA are 97% identical. Northern blot analysis revealed that ARHGDIA was expressed in all cell lines and tissues tested.