UniProt:O75533 SF3B1

chain
  • chain:1-1304
checksum 12F051757D2B9DEE
comment
  • FUNCTION Component of the 17S U2 SnRNP complex of the spliceosome, a large ribonucleoprotein complex that removes introns from transcribed pre-mRNAs (PubMed:12234937, PubMed:27720643, PubMed:32494006, PubMed:34822310, PubMed:36104565). The 17S U2 SnRNP complex (1) directly participates in early spliceosome assembly and (2) mediates recognition of the intron branch site during pre-mRNA splicing by promoting the selection of the pre-mRNA branch-site adenosine, the nucleophile for the first step of splicing (PubMed:32494006, PubMed:34822310, PubMed:36104565). Within the 17S U2 SnRNP complex, SF3B1 is part of the SF3B subcomplex, which is required for 'A' complex assembly formed by the stable binding of U2 snRNP to the branchpoint sequence in pre-mRNA (PubMed:12234937, PubMed:36104565). Sequence independent binding of SF3A and SF3B subcomplexes upstream of the branch site is essential, it may anchor U2 snRNP to the pre-mRNA (PubMed:12234937). May also be involved in the assembly of the 'E' complex (PubMed:10882114). Also acts as a component of the minor spliceosome, which is involved in the splicing of U12-type introns in pre-mRNAs (PubMed:15146077, PubMed:33509932). Together with other U2 snRNP complex components may also play a role in the selective processing of microRNAs (miRNAs) from the long primary miRNA transcript, pri-miR-17-92 (By similarity).SUBUNIT Component of the 17S U2 SnRNP complex, a ribonucleoprotein complex that contains small nuclear RNA (snRNA) U2 and a number of specific proteins (PubMed:30567737, PubMed:32494006, PubMed:34822310, PubMed:36797247). Part of the SF3B subcomplex of the 17S U2 SnRNP complex (PubMed:12234937, PubMed:12738865, PubMed:27720643, PubMed:28541300). SF3B associates with the splicing subcomplex SF3A and a 12S RNA unit to form the U2 small nuclear ribonucleoproteins complex (U2 snRNP) (PubMed:12234937). Within the SF3B complex, interacts directly (via HEAT domain) with SF3B3, SF3B5, SF3B6 and (via HEAT domain) with PHF5A (PubMed:16432215, PubMed:21062891, PubMed:27720643, Ref.41). The SF3B subcomplex interacts with U2AF2 (PubMed:27720643). Identified in the spliceosome C complex (PubMed:11991638). Component of the minor (U12-type spliceosome) spliceosome (PubMed:15146077, PubMed:33509932). Within the minor spliceosome complex, interacts with SCNM1 and CRIPT (PubMed:33509932). Component of the B-WICH complex, at least composed of SMARCA5/SNF2H, BAZ1B/WSTF, SF3B1, DEK, MYO1C, ERCC6, MYBBP1A and DDX21 (PubMed:16603771). Phosphorylated form interacts with PPP1R8 (PubMed:12105215). Interacts with PQBP1 (PubMed:23512658). Interacts with RBM17 (PubMed:17589525). Interacts with RBM39 (PubMed:24795046). Interacts with SETX (PubMed:21700224). Interacts with RBM15 (PubMed:26575292). Interacts with USH1G (PubMed:34023904). Interacts with SDE2 (PubMed:34365507). Interacts with U2AF1 (PubMed:34365507). Interacts with CACTIN (PubMed:34365507). Interacts with ZRSR1 (By similarity). Interacts with CYREN (PubMed:37813856).INTERACTION During mitosis, transiently dispersed from the nuclear speckles to the cytoplasm.ALTERNATIVE PRODUCTS Phosphorylation occurs concomitantly with the splicing catalytic steps (PubMed:12105215, PubMed:9585501). Phosphorylation on Thr-244, Thr-248 and Thr-313 by cyclin-dependent kinases promotes interaction with PPP1R8 during mitosis (PubMed:12105215). Phosphorylation by CDK11 enables the association between SF3B1 and U5 and U6 snRNAs in the activated spliceosome, thereby promoting spliceosome assembly (PubMed:36104565, PubMed:38059508).PTM Citrullinated by PADI4.SIMILARITY Belongs to the SF3B1 family.
crossReference
databaseName UniProt
dbId 69807
description
  • recommendedName: Splicing factor 3B subunit 1 alternativeName: Pre-mRNA-splicing factor SF3b 155 kDa subunit shortName evidence="35"SF3b155 alternativeName: fullName evidence="33"Spliceosome-associated protein 155 shortName evidence="33"SAP 155
displayName UniProt:O75533 SF3B1
geneName
  • SF3B1
  • SAP155
identifier O75533
isSequenceChanged false
keyword
  • 3D-structure
  • Acetylation
  • Alternative splicing
  • Citrullination
  • Isopeptide bond
  • mRNA processing
  • mRNA splicing
  • Nucleus
  • Phosphoprotein
  • Proteomics identification
  • Reference proteome
  • Repeat
  • RNA-binding
  • Spliceosome
  • Ubl conjugation
modified [InstanceEdit:9983091] Weiser, Joel, 2026-02-20
moleculeType Protein
name
  • SF3B1
physicalEntity
referenceDatabase [ReferenceDatabase:2] UniProt
referenceGene
referenceTranscript
schemaClass ReferenceGeneProduct
secondaryIdentifier
  • SF3B1_HUMAN
  • E9PCH3
sequenceLength 1304
species [Species:48887] Homo sapiens
stId uniprot:O75533
url http://purl.uniprot.org/uniprot/O75533

Referrals

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