C-terminal SARAH domain found in Ras-association domain-containing protein 5 (RASSF5)
RASSF5, also called New ras effector 1 (NORE1), or regulator for cell adhesion and polarization enriched in lymphoid tissues (RAPL), 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 may be involved in lymphocyte adhesion by linking RAP1A activation upon T-cell receptor or chemokine stimulation to integrin activation. RASSF5 is expressed as three transcripts (A-C) via differential promoter usage and alternative splicing. RASSF5A is a pro-apoptotic Ras effector and functions as a Ras regulated tumor suppressor. RASSF5C is regulated by Ras related protein and modulates cellular adhesion. All transcript variants of RASSF5 contain the RA and SARAH (Salvador-RassF-Hippo) domains. 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 RASSF5, that mediates homo- and heterodimerization.
Jiyao W et al.(2023). "The conserved domain database in 2023.",