A coactivator of pre-mRNA splicing.
The nuclear matrix antigen recognized by the monoclonal antibody (mAb) B1C8 is a novel serine (S) and arginine (R)-rich protein associated with splicing complexes and is named here SRm160 (SR-related matrix protein of 160 kD). SRm160 contains multiple SR repeats, but unlike proteins of the SR family of splicing factors, lacks an RNA recognition motif. SRm160 and a related protein SRm300 (the 300-kD nuclear matrix antigen recognized by mAb B4A11) form a complex that is required for the splicing of specific pre-mRNAs. The SRm160/300 complex associates with splicing complexes and promotes splicing through interactions with SR family proteins. Binding of SRm160/300 to pre-mRNA is normally also dependent on U1 snRNP and is stabilized by U2 snRNP. Thus, SRm160/300 forms multiple interactions with components bound directly to important sites within pre-mRNA. The results suggest that a complex of the nuclear matrix proteins SRm160 and SRm300 functions as a coactivator of pre-mRNA splicing.
Pubmed ID: 9531537 RIS Download
Amino Acid Sequence | Antigens, Nuclear | Bacterial Proteins | HeLa Cells | Humans | Interphase | Lymphoma, Large B-Cell, Diffuse | Metaphase | Molecular Sequence Data | Nuclear Matrix | Nuclear Matrix-Associated Proteins | Nuclear Proteins | RNA Precursors | RNA-Binding Proteins | Ribonucleoprotein, U1 Small Nuclear | Ribonucleoprotein, U2 Small Nuclear | Sequence Alignment | Sequence Homology, Amino Acid | Spliceosomes | Tumor Cells, Cultured