May act as scaffolding protein, and as adapter protein to couple membrane receptors to intracellular signaling pathways. Acts as a mediator of cell spreading and actin cytoskeleton rearrangement. Core component of the CTLH E3 ubiquitin-protein ligase complex that mediates ubiquitination and subsequent proteasomal degradation of target proteins. Identified in the CTLH complex that contains at least MAEA, RMND5A (or alternatively its paralog RMND5B), GID8, WDR26, and RANBP9 and/or RANBP10. Predominantly cytoplasmic. Belongs to the RANBP9/10 family.