Characterization of HeLa nuclear factors which interact with a conditionally processed rat fibronectin pre-mRNA.
It is demonstrated that several HeLa nuclear proteins interact in a magnesium-dependent fashion with a conditionally processed pre-mRNA derived from an alternatively spliced region of the rat fibronectin gene. HnRNP C proteins crosslink under both permissive and non-permissive conditions (high and low magnesium, respectively), whereas hnRNP I/PTB is observed only under the latter. Thus hnRNP I/PTB represents a potential inhibitor of splicing for this intron. A protein that was observed to crosslink under permissive conditions has been identified as splicing factor U2AF65, which thus represents a candidate positive factor in the splicing of this pre-mRNA. We interpret these results with a working model for the conditional selection of the 3' splice site of alternative exon EIIIB.
Norton
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Dept. of Medicine, Roger Williams Hospital, Providence, RI.
Hynes
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D002467:Cell Nucleus / Q000378:metabolism; D003432:Cross-Linking Reagents; D005353:Fibronectins / Q000096:biosynthesis / Q000235:genetics*; D006367:HeLa Cells; D034482:Heterogeneous-Nuclear Ribonucleoprotein Group C; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D008274:Magnesium / Q000494:pharmacology; D009687:Nuclear Proteins / Q000302:isolation & purification / Q000378:metabolism*; D012322:RNA Precursors / Q000378:metabolism*; D012332:RNA, Heterogeneous Nuclear / Q000378:metabolism; D012261:Ribonucleoproteins / Q000378:metabolism*; D014466:Ultraviolet Rays
D003432:Cross-Linking Reagents; D005353:Fibronectins; D034482:Heterogeneous-Nuclear Ribonucleoprotein Group C; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D009687:Nuclear Proteins; D012322:RNA Precursors; D012332:RNA, Heterogeneous Nuclear; D012261:Ribonucleoproteins; D008274:Magnesium