Rho GTPase Activating Protein 1 (ARHGAP1)

RHOGAP stimulated the GTPase activity of p21-Rho but not other small molecular mass GTP-binding proteins. Diekmann et al. (1991) reported a partial amino acid sequence of RHOGAP. Using PCR with primers based on the RHOGAP protein sequence, Lancaster et al. (1994) isolated a human fibrosarcoma cell line cDNA encoding RHOGAP. Northern blot analysis revealed that RHOGAP is expressed as a 3.6-kb mRNA. The RHOGAP cDNA encodes a predicted 439-amino acid protein with a calculated molecular mass of 50 kD. Since antibodies against RHOGAP detected a 50-kD protein on Western blots of cell extracts, Lancaster et al. (1994) suggested that the previously observed 29-kD protein was a C-terminal proteolytic fragment of RHOGAP that was generated during protein purification.