C-terminal SARAH domain found in Ras-association domain-containing protein 1 (RASSF1)
RASSF1 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. It acts as a potential tumor suppressor that is required for death receptor-dependent apoptosis. It mediates activation of STK3/MST2 and STK4/MST1 during Fas-induced apoptosis by preventing their dephosphorylation. RASSF1 has eight transcripts (A-H) arising from alternative splicing and differential promoter usage. RASSF1A and 1C are the most extensively studied RASSF1, with both localized to microtubules and involved in regulation of growth and migration. With the exception of some minor splice variants (RASSF1F and RASSF1G), RASSF1 contains an RA domain and a C-terminal SARAH (Salvador-RassF-Hippo) protein-protein interaction motif. 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 RASSF1.
Jiyao W et al.(2023). "The conserved domain database in 2023.",