SPOC (Spen paralog and ortholog C-terminal) domain found in RNA binding motif protein 15 (RBM15) and similar proteins
This subfamily includes RBM15, RBM15B, and similar proteins found in metazoans. RBM15, also called one-twenty two protein 1 (OTT1), is a novel mRNA export factor and component of the NXF1 pathway. It binds to NXF1 and serves as a receptor for the RNA export element RTE. It also possesses mRNA export activity and can facilitate the access of DEAD-box protein DBP5 to mRNA at the nuclear pore complex (NPC). RNA-binding protein 15B (RBM15B), also called one-twenty two 3 (OTT3), is a paralog of RBM15 and therefore has post-transcriptional regulatory activity. It is a nuclear protein that shares with RBM15, the association with the splicing factor compartment and the nuclear envelope, as well as the binding to mRNA export factors NXF1 and Aly/REF. Members of this family have a domain architecture comprising of three N-terminal RNA recognition motifs (RRMs), also known as RBD (RNA binding domain) or RNP (ribonucleoprotein domain), and a C-terminal SPOC domain. This model corresponds to the SPOC domain that is involved in developmental signaling and has also been proposed to be a phosphorylation binding module.
Jiyao W et al.(2023). "The conserved domain database in 2023.",