Involved in pre-mRNA splicing as component of the spliceosome (PubMed:11991638, PubMed:28502770, PubMed:28781166, PubMed:28076346). Associated with sn-RNP U2, where it contributes to the binding of stem loop IV of U2 snRNA (PubMed:9716128). Identified in the spliceosome B complex (PubMed:28781166). Identified in the spliceosome C complex (PubMed:11991638, PubMed:28502770, PubMed:28076346). Present in a spliceosome complex assembled in vitro, and composed of SNRPB2, HPRP8BP and CRNKL1 (PubMed:12084575). Contributes to the binding of stem loop IV of U2 snRNA with SNRPP1 (PubMed:9716128). Patients with systemic lupus erythematosus produce antibodies which interact with snRNP proteins. Belongs to the RRM U1 A/B'' family.