SNRPB

The protein encoded by this gene is one of several nuclear proteins that are found in common among U1, U2, U4/U6, and U5 small ribonucleoprotein particles (snRNPs). These snRNPs are involved in pre-mRNA splicing, and the encoded protein may also play a role in pre-mRNA splicing or snRNP structure. Autoantibodies from patients with systemic lupus erythematosus frequently recognize epitopes on the encoded protein. Two transcript variants encoding different isoforms (B and B') have been found for this gene. [provided by RefSeq]

Full Name

small nuclear ribonucleoprotein polypeptides B and B1

Function

Plays a role in pre-mRNA splicing as a core component of the spliceosomal U1, U2, U4 and U5 small nuclear ribonucleoproteins (snRNPs), the building blocks of the spliceosome (PubMed:11991638, PubMed:18984161, PubMed:19325628, PubMed:25555158, PubMed:26912367, PubMed:28502770, PubMed:28781166, PubMed:28076346).
Component of both the pre-catalytic spliceosome B complex and activated spliceosome C complexes (PubMed:11991638, PubMed:28502770, PubMed:28781166, PubMed:28076346).
Is also a component of the minor U12 spliceosome (PubMed:15146077).
As part of the U7 snRNP it is involved in histone pre-mRNA 3'-end processing (PubMed:12975319).

Biological Process

Biological Process 7-methylguanosine cap hypermethylation1 PublicationIC:ComplexPortal
Biological Process brain developmentIEA:Ensembl
Biological Process mRNA splicing, via spliceosomeManual Assertion Based On ExperimentIDA:UniProtKB
Biological Process protein methylationManual Assertion Based On ExperimentIDA:MGI
Biological Process RNA splicingManual Assertion Based On ExperimentTAS:ProtInc
Biological Process spliceosomal snRNP assemblyManual Assertion Based On ExperimentIDA:UniProtKB
Biological Process U2-type prespliceosome assembly1 PublicationIC:ComplexPortal

Cellular Location

Cytoplasm, cytosol
Nucleus
SMN-mediated assembly into core snRNPs occurs in the cytosol before SMN-mediated transport to the nucleus to be included in spliceosomes.

Involvement in disease

Cerebrocostomandibular syndrome (CCMS):
A syndrome characterized by severe micrognathia, rib defects ranging from a few dorsal rib segments to complete absence of ossification, and intellectual disability.

PTM

Methylated by PRMT5 (By similarity).
Arg-108 and Arg-112 are dimethylated, probably to asymmetric dimethylarginine (PubMed:16087681, Ref.10).