RNPS1
Description
The RNPS1 (RNA binding protein with serine rich domain 1) is a protein-coding gene located on chromosome 16.
RNA-binding protein with serine-rich domain 1 is a protein that in humans is encoded by the RNPS1 gene.
== Function == This gene encodes a protein that is part of a post-splicing multiprotein complex, the exon junction complex, involved in both mRNA nuclear export and mRNA surveillance. mRNA surveillance detects exported mRNAs with truncated open reading frames and initiates nonsense-mediated mRNA decay (NMD). When translation ends upstream from the last exon-exon junction, this triggers NMD to degrade mRNAs containing premature stop codons. This protein binds to the mRNA and remains bound after nuclear export, acting as a nucleocytoplasmic shuttling protein. This protein contains many serine residues. Two splice variants have been found for this gene; both variants encode the same protein.
== Interactions == RNPS1 has been shown to interact with SART3 and Pinin.
RNPS1 is part of pre- and post-splicing multiprotein mRNP complexes. It is an auxiliary component of the splicing-dependent multiprotein exon junction complex (EJC) deposited at splice junctions on mRNAs. The EJC is a dynamic structure consisting of core proteins and several peripheral nuclear and cytoplasmic associated factors that join the complex only transiently either during EJC assembly or during subsequent mRNA metabolism. RNPS1 is also a component of the ASAP and PSAP complexes which bind RNA in a sequence-independent manner and are proposed to be recruited to the EJC prior to or during the splicing process to regulate specific excision of introns in specific transcription subsets. The ASAP complex can inhibit RNA processing during in vitro splicing reactions. The ASAP complex promotes apoptosis and is disassembled after induction of apoptosis. RNPS1 enhances the formation of the ATP-dependent A complex of the spliceosome. It is involved in both constitutive splicing and, in association with SRP54 and TRA2B/SFRS10, in distinctive modulation of alternative splicing in a substrate-dependent manner. It is involved in the splicing modulation of BCL2L1/Bcl-X (and probably other apoptotic genes); specifically inhibiting formation of proapoptotic isoforms such as Bcl-X(S); the activity is different from the established EJC assembly and function. RNPS1 participates in mRNA 3'-end cleavage. It is involved in UPF2-dependent nonsense-mediated decay (NMD) of mRNAs containing premature stop codons. It also mediates increase of mRNA abundance and translational efficiency. It binds spliced mRNA 20-25 nt upstream of exon-exon junctions.
RNPS1 is also known as E5.1.
