SAP155 (SF3B1) Antibody – Rabbit Polyclonal

This gene encodes subunit 1 of the splicing factor 3b protein complex. Splicing factor 3b, together with splicing factor 3a and a 12S RNA unit, forms the U2 small nuclear ribonucleoproteins complex (U2 snRNP). The splicing factor 3b/3a complex binds pre-mRNA upstream of the intron's branch site in a sequence independent manner and may anchor the U2 snRNP to the pre-mRNA. Splicing factor 3b is also a component of the minor U12-type spliceosome. The carboxy-terminal two-thirds of subunit 1 have 22 non-identical, tandem HEAT repeats that form rod-like, helical structures. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Jul 2008]

SF3B1: subunit of the splicing factor SF3B required for 'A' complex assembly formed by the stable binding of U2 snRNP to the branchpoint sequence (bps) in pre-mRNA. Sequence independent binding of SF3A/SF3B complex upstream of the branch site is essential, it may anchor U2 snRNP to the pre-mRNA. May also be involved in the assembly of the 'E' complex. Belongs also to the minor U12-dependent spliceosome, which is involved in the splicing of rare class of nuclear pre-mRNA intron. Phosphorylated during the splicing catalytic steps.

Protein type: Spliceosome; RNA-binding; RNA splicing

Chromosomal Location of Human Ortholog: 2q33.1

Cellular Component: nucleoplasm; spliceosome; nuclear speck; nucleus; U12-dependent spliceosome

Molecular Function: protein binding; chromatin binding

Biological Process: anterior/posterior pattern formation; RNA splicing, via transesterification reactions; nuclear mRNA splicing, via spliceosome; RNA splicing; gene expression

Disease: Myelodysplastic Syndrome