SART3
Description
The SART3 (spliceosome associated factor 3, U4/U6 recycling protein) is a protein-coding gene located on chromosome 12.
SART3 (Squamous cell carcinoma antigen recognized by T-cells 3) is a protein encoded by the SART3 gene in humans. It is an RNA-binding nuclear protein that serves as a tumor-rejection antigen, containing tumor epitopes capable of inducing HLA-A24-restricted and tumor-specific cytotoxic T lymphocytes in cancer patients. This makes SART3 potentially useful for specific immunotherapy. SART3 is crucial for HIV-1 gene expression and viral replication, and it associates transiently with U6 and U4/U6 snRNPs during the recycling phase of the spliceosome cycle. SART3 is believed to be involved in the regulation of mRNA splicing. SART3 has been shown to interact with RNPS1 and Androgen receptor.
SART3 is a U6 snRNP-binding protein that functions as a recycling factor of the splicing machinery. It promotes the initial reassembly of U4 and U6 snRNPs following their ejection from the spliceosome during its maturation. SART3 also binds U6atac snRNPs and may function as a recycling factor for U4atac/U6atac spliceosomal snRNP, an initial step in the assembly of U12-type spliceosomal complex. The U12-type spliceosomal complex plays a role in the splicing of introns with non-canonical splice sites. SART3 may also function as a substrate-targeting factor for deubiquitinases like USP4 and USP15. It recruits USP4 to ubiquitinated PRPF3 within the U4/U5/U6 tri-snRNP complex, promoting PRPF3 deubiquitination and thereby regulating the spliceosome U4/U5/U6 tri-snRNP spliceosomal complex disassembly. SART3 may also recruit the deubiquitinase USP15 to histone H2B and mediate histone deubiquitination, thereby regulating gene expression and/or DNA repair. SART3 may play a role in hematopoiesis probably through transcription regulation of specific genes including MYC.
SART3 is also known as DSAP1, P100, RP11-13G14, TIP110, p110, p110(nrb).
