Ras Interacting Protein 1 (RASIP1)

The RASIP1 cDNA encodes a deduced 962-amino acid, highly basic protein. The protein contains a single RA (Ras-associating) domain in the N terminus that shows high homology to the RA domain of human AF6 (MLLT4), a putative Ras/Rap effector, and possesses a conserved basic residue (arg182) found to be critical for the interaction of other Ras effectors with Ras. RASIP1 also contains a proline-rich region similar to the Src homology-3 (SH3) domain binding motifs found in many intracellular proteins, and a putative dilute (DIL) domain found in AF6 and in the globular tail of myosin V proteins. Northern blot analysis revealed an approximately 3.5-kb RASIP1 transcript in all human tissues examined, with highest expression in heart. Western blot analysis on mouse tissues indicated that RASIP1 encodes a 115-kD protein.