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.
Publication types
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Antigens, Nuclear*
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Bacterial Proteins / metabolism
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HeLa Cells / metabolism
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Humans
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Interphase / physiology
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Lymphoma, Large B-Cell, Diffuse / pathology
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Metaphase / physiology
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Molecular Sequence Data
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Nuclear Matrix / immunology
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Nuclear Matrix-Associated Proteins*
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Nuclear Proteins / genetics*
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Nuclear Proteins / immunology
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RNA Precursors / genetics
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RNA Precursors / metabolism*
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RNA-Binding Proteins / genetics*
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RNA-Binding Proteins / immunology
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Ribonucleoprotein, U1 Small Nuclear / metabolism
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Ribonucleoprotein, U2 Small Nuclear / metabolism
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Sequence Alignment
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Sequence Homology, Amino Acid
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Spliceosomes / genetics
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Spliceosomes / metabolism*
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Tumor Cells, Cultured
Substances
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Antigens, Nuclear
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Bacterial Proteins
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Nuclear Matrix-Associated Proteins
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Nuclear Proteins
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RNA Precursors
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RNA-Binding Proteins
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Ribonucleoprotein, U1 Small Nuclear
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Ribonucleoprotein, U2 Small Nuclear
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SR protein, bacteria
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SRRM1 protein, human