C-terminal SARAH domain found in Ras-association domain-containing protein 3 (RASSF3)
RASSF3 is one of six related proteins, the classical RASSF proteins (RASSF1-6), that contain a conserved RalGDS/AF6 Ras association (RA) domain located towards the C-terminus. RASSF3 has three transcripts (A-C) due to alternative splicing of the exons. The RASSF3B and 3C isoforms are shorter than RASSF3A, and unlike RASSF3A do not contain the RA or SARAH (Salvador-RassF-Hippo) domains. RASSF3A regulates apoptosis and the cell cycle via p53 stabilization and is possibly involved in DNA repair. The RA domain of the classical RASSF proteins has a beta-grasp ubiquitin-like fold with low sequence similarity to ubiquitin. The RA domain mediates interactions with Ras and other small GTPases, and the SARAH domain mediates protein-protein interactions crucial in the pathways that induce cell cycle arrest and apoptosis. This model corresponds to the SARAH domain of RASSF3.