SF3B1
SF3B1 (splicing factor 3b subunit 1, also known as SAP155, SF3b155, PRPF10, Prp10 and Hsh155) is a core component of the U2 snRNP of the spliceosome. It helps recognise the intron branch site during pre-mRNA splicing. Browse Assay Genie's current range of SF3B1 research reagents below, or read on for the biology behind the target.
SF3B1 is a component of the 17S U2 snRNP complex of the spliceosome, the large ribonucleoprotein complex that removes introns from transcribed pre-mRNAs. The 17S U2 snRNP takes part directly in early spliceosome assembly and mediates recognition of the intron branch site by promoting selection of the branch-site adenosine, the nucleophile for the first step of splicing. Within this complex, SF3B1 sits in the SF3B subcomplex, which is required for assembly of the 'A' complex, formed by stable binding of U2 snRNP to the branchpoint sequence in pre-mRNA.
Sequence-independent binding of the SF3A and SF3B subcomplexes upstream of the branch site is essential and may anchor U2 snRNP to the pre-mRNA. SF3B1 may also be involved in assembly of the 'E' complex. It is also a component of the minor spliceosome, which splices U12-type introns. Together with other U2 snRNP components, it may play a role in the selective processing of microRNAs from the long primary transcript pri-miR-17-92. Splicing factor 3b combines with splicing factor 3a and a 12S RNA unit to form the U2 snRNP. Studies of the SF3B1 protein typically place it in the nucleus, including nuclear speckles.
The SF3B1 gene encodes a protein whose carboxy-terminal two-thirds contain 22 non-identical, tandem HEAT repeats that form rod-like, helical structures. HGNC places it among armadillo-like helical domain containing proteins, the SF3b complex and the B-WICH chromatin-remodelling complex subunits. Alternative splicing of the gene results in multiple transcript variants encoding different isoforms. Earlier names include splicing factor 3b, subunit 1, 155kD, and the mouse ortholog is Sf3b1.
SF3B1 participates in early spliceosome assembly and in formation of the 'A' complex, making it central to work on how U2 snRNP engages pre-mRNA.
By promoting selection of the branch-site adenosine, SF3B1 is a focus for research into how introns are defined during the first step of splicing.
As a component of the minor spliceosome, SF3B1 is relevant to investigations of U12-type intron splicing in pre-mRNAs.
SF3B1 and other U2 snRNP components may contribute to selective processing of miRNAs from the pri-miR-17-92 primary transcript.
SF3B1 is part of the 17S U2 snRNP of the spliceosome. It helps U2 snRNP bind the branchpoint sequence, promoting selection of the branch-site adenosine for the first splicing step. It is also a component of the minor spliceosome, which handles U12-type introns.
SF3B1 is also called SAP155, SF3b155, PRPF10, Prp10 and Hsh155. Older HGNC names are splicing factor 3b, subunit 1, 155kD. The gene produces multiple transcript variants through alternative splicing, encoding different isoforms.
The carboxy-terminal two-thirds of SF3B1 contain 22 non-identical, tandem HEAT repeats that form rod-like, helical structures. HGNC classes it with armadillo-like helical domain proteins and the SF3b complex. A mouse ortholog, Sf3b1, exists; check the datasheet of any product for its validated reactivity.
Other splicing factors and SF3b complex partners with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt O75533; product specifications from Assay Genie datasheets.