Yeast Nop3p has structural and functional similarities to mammalian pre-mRNA binding proteins.
Indirect immunofluorescence shows the yeast protein Nop3p/Np13p/Mts1p to be localized both in the nucleoplasm and the nucleolus. Here we show that Nop3p can be efficiently UV cross-linked in vivo to poly(A)+ RNA. In higher eukaryotes it would therefore be classed as a heterogeneous nuclear ribonucleoprotein (hnRNP) component. As judged by immunofluorescence and in situ hybridization, a temperature-sensitive allele of nop3 leads to the accumulation of poly(A)+ RNA in the nucleus at non-permissive temperature. The sequence of Nop3p shows homology to the larger members of the SR protein family of splicing factors, particularly in the RRMH domain. We have, however, detected no splicing defects in strains genetically depleted to Nop3p or carrying a temperature-sensitive allele.
Russell
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I
European Molecular Biology Laboratory, Heidelberg, Germany.
Tollervey
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D
D002451:Cell Compartmentation; D002466:Cell Nucleolus / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D002467:Cell Nucleus / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D005656:Fungal Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017404:In Situ Hybridization, Fluorescence; D008856:Microscopy, Fluorescence; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011485:Protein Binding; D012322:RNA Precursors / Q000378:metabolism*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism* / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins; D000068103:Serine-Arginine Splicing Factors
D005656:Fungal Proteins; C077734:NPL3 protein, S cerevisiae; D009687:Nuclear Proteins; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D029701:Saccharomyces cerevisiae Proteins; D000068103:Serine-Arginine Splicing Factors