title: A coactivator of pre-mRNA splicing.
abstract: 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.
authors.affiliation: Center for Cancer Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 USA.
authors.forename: B J
authors.initials: BJ
authors.lastname: Blencowe
authors.forename: R
authors.initials: R
authors.lastname: Issner
authors.forename: J A
authors.initials: JA
authors.lastname: Nickerson
authors.forename: P A
authors.initials: PA
authors.lastname: Sharp
mesh_terms: D000595:Amino Acid Sequence; D034961:Antigens, Nuclear; D001426:Bacterial Proteins / Q000378:metabolism; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D007399:Interphase / Q000502:physiology; D016403:Lymphoma, Large B-Cell, Diffuse / Q000473:pathology; D008677:Metaphase / Q000502:physiology; D008969:Molecular Sequence Data; D015530:Nuclear Matrix / Q000276:immunology; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins / Q000235:genetics* / Q000276:immunology; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000276:immunology; D017412:Ribonucleoprotein, U1 Small Nuclear / Q000378:metabolism; D017413:Ribonucleoprotein, U2 Small Nuclear / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D017381:Spliceosomes / Q000235:genetics / Q000378:metabolism*; D014407:Tumor Cells, Cultured
chemical_list: D034961:Antigens, Nuclear; D001426:Bacterial Proteins; D034521:Nuclear Matrix-Associated Proteins; D009687:Nuclear Proteins; D012322:RNA Precursors; D016601:RNA-Binding Proteins; D017412:Ribonucleoprotein, U1 Small Nuclear; D017413:Ribonucleoprotein, U2 Small Nuclear; C063999:SR protein, bacteria; C111710:SRRM1 protein, human