May act as an adapter protein to couple membrane receptors to intracellular signaling pathways (Probable). Core component of the CTLH E3 ubiquitin-protein ligase complex that selectively accepts ubiquitin from UBE2H and mediates ubiquitination and subsequent proteasomal degradation of the transcription factor HBP1 (By similarity). Enhances dihydrotestosterone-induced transactivation activity of AR, as well as dexamethasone-induced transactivation activity of NR3C1, but does not affect estrogen-induced transactivation (By similarity). Acts as a guanine nucleotide exchange factor (GEF) for RAN GTPase (PubMed:18347012). May play an essential role in hemostasis and in maintaining microtubule dynamics with respect to both platelet shape and function (PubMed:19801445). May form homodimers. Identified in the CTLH complex that contains GID4, RANBP9 and/or RANBP10, MKLN1, MAEA, RMND5A (or alternatively its paralog RMND5B), GID8, ARMC8, WDR26 and YPEL5. Within this complex, MAEA, RMND5A (or alternatively its paralog RMND5B), GID8, WDR26, and RANBP9 and/or RANBP10 form the catalytic core, while GID4, MKLN1, ARMC8 and YPEL5 have ancillary roles. Interacts with RAN and RANBP9. Interacts with the HGF receptor MET. Interacts with AR (By similarity). Interacts with TUBB1 (PubMed:18347012). Interacts with YPEL5 (By similarity). May interact with TUBB5 (PubMed:18347012). Interacts with DDX4 (PubMed:27622290). Predominantly cytoplasmic. Associates with cytoplasmic microtubules in mature megakaryocytes and platelets. Expressed at highest levels in spleen and liver. Expressed in megakaryocytes and platelets (at protein level). The SPRY domain mediates the interaction with MET. Mutant mice are viable and show no conspicuous phenotype. They have normal platelet counts and only slightly reduced proplatelet formation. Resting platelets tend to have a more spherical shape. Many platelets exhibit disorders in microtubule filament numbers and localization. The animals show a markedly prolonged bleeding time. Granule release is also reduced. Belongs to the RANBP9/10 family. Truncated N-terminus. Extended N-terminus.