scholarly journals The NSR1 gene encodes a protein that specifically binds nuclear localization sequences and has two RNA recognition motifs.

1991 ◽  
Vol 113 (1) ◽  
pp. 1-12 ◽  
Author(s):  
W C Lee ◽  
Z X Xue ◽  
T Mélèse
Keyword(s):  
Nuclear Localization ◽  
Partial Purification ◽  
Nuclear Localization Sequence ◽  
Affinity Column ◽  
Rna Recognition ◽  
Yeast Saccharomyces Cerevisiae ◽  
Rna Recognition Motifs ◽  
Localization Sequence ◽  
Recognition Motifs ◽  
Nuclear Localization Sequences

We previously identified a protein (p67) in the yeast, Saccharomyces cerevisiae, that specifically recognizes nuclear localization sequences. We report here the partial purification of p67, and the isolation, sequencing, and disruption of the gene (NSR1) encoding this protein. p67 was purified using an affinity column conjugated with a peptide containing the histone H2B nuclear localization sequence from yeast. Using antibodies against p67 we have cloned the gene for this protein. The protein encoded by the NSR1 gene recognizes the wild-type H2B nuclear localization sequence, but does not recognize a mutant H2B sequence that is incompetent for nuclear localization in vivo. Interestingly, the NSR1 protein has two RNA recognition motifs, as well as an acidic NH2 terminus containing a series of serine clusters, and a basic COOH terminus containing arg-gly repeats. We have confirmed the nuclear localization of p67 by immunofluorescence and found that a restricted portion of the nucleus is highlighted. We have also shown that NSR1 (p67) is required for normal cell growth.

Domain necessary for Drosophila ELAV nuclear localization: function requires nuclear ELAV

1999 ◽  
Vol 112 (24) ◽  
pp. 4501-4512 ◽  
Author(s):  
Y.M. Yannoni ◽  
K. White
Keyword(s):  
Nuclear Localization ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Nuclear Localization Sequence ◽  
Rna Recognition ◽  
Rna Recognition Motifs ◽  
Mutant Proteins ◽  
Localization Sequence ◽  
Recognition Motifs

The neuron specific Drosophila ELAV protein belongs to the ELAV family of RNA binding proteins which are characterized by three highly conserved RNA recognition motifs, an N-terminal domain, and a hinge region between the second and third RNA recognition motifs. Despite their highly conserved RNA recognition motifs the ELAV family members are a group of proteins with diverse posttranscriptional functions including splicing regulation, mRNA stability and translatability and have a variety of subcellular localizations. The role of the ELAV hinge in localization and function was examined using transgenes encoding ELAV hinge deletions, in vivo. Subcellular localization of the hinge mutant proteins revealed that residues between amino acids 333–374 are necessary for nuclear localization. This delineated sequence has no significant homology to classical nuclear localization sequences, but it is similar to the recently characterized nucleocytoplasmic shuttling sequence, the HNS, from a human ELAV family member, HuR. This defined sequence, however, was insufficient for nuclear localization as tested using hinge-GFP fusion proteins. Functional assays revealed that mutant proteins that fail to localize to the nucleus are unable to provide ELAV vital function, but their function is significantly restored when translocated into the nucleus by a heterologous nuclear localization sequence tag.

scholarly journals Multiple regions of NSR1 are sufficient for accumulation of a fusion protein within the nucleolus.

1993 ◽  
Vol 123 (5) ◽  
pp. 1081-1091 ◽  
Author(s):  
C Yan ◽  
T Mélèse
Keyword(s):  
Fusion Protein ◽  
Nuclear Localization ◽  
Ribosome Biogenesis ◽  
Nuclear Localization Sequence ◽  
Rna Recognition Motif ◽  
Rna Recognition ◽  
Rich Region ◽  
Rna Recognition Motifs ◽  
Recognition Motifs ◽  
Beta Galactosidase

NSR1, a 67-kD nucleolar protein, was originally identified in our laboratory as a nuclear localization signal binding protein, and has subsequently been found to be involved in ribosome biogenesis. NSR1 has three regions: an acidic/serine-rich NH2 terminus, two RNA recognition motifs, and a glycine/arginine-rich COOH terminus. In this study we show that NSR1 itself has a bipartite nuclear localization sequence. Deletion of either basic amino acid stretch results in the mislocation of NSR1 to the cytoplasm. We further demonstrate that either of two regions, the NH2 terminus or both RNA recognition motifs, are sufficient to localize a bacterial protein, beta-galactosidase, to the nucleolus. Intensive deletion analysis has further defined a specific acidic/serine-rich region within the NH2 terminus as necessary for nucleolar accumulation rather than nucleolar targeting. In addition, deletion of either RNA recognition motif or point mutations in one of the RNP consensus octamers results in the mislocalization of a fusion protein within the nucleus. Although the glycine/arginine-rich region in the COOH terminus is not sufficient to bring beta-galactosidase to the nucleolus, our studies show that this domain is necessary for nucleolar accumulation when an RNP consensus octamer in one of the RNA recognition motifs is mutated. Our findings are consistent with the notion that nucleolar localization is a result of the binding interactions of various domains of NSR1 within the nucleolus rather than the presence of a specific nucleolar targeting signal.

scholarly journals RNA-dependent chromatin association of transcription elongation factors and Pol II CTD kinases

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Sofia Battaglia ◽  
Michael Lidschreiber ◽  
Carlo Baejen ◽  
Phillipp Torkler ◽  
Seychelle M Vos ◽  
...  
Keyword(s):  
Rna Recognition ◽  
Elongation Factors ◽  
Elongation Complex ◽  
Yeast Saccharomyces Cerevisiae ◽  
Rna Recognition Motifs ◽  
Pol Ii ◽  
Recognition Motifs ◽  
Rna Interaction

For transcription through chromatin, RNA polymerase (Pol) II associates with elongation factors (EFs). Here we show that many EFs crosslink to RNA emerging from transcribing Pol II in the yeast Saccharomyces cerevisiae. Most EFs crosslink preferentially to mRNAs, rather than unstable non-coding RNAs. RNA contributes to chromatin association of many EFs, including the Pol II serine 2 kinases Ctk1 and Bur1 and the histone H3 methyltransferases Set1 and Set2. The Ctk1 kinase complex binds RNA in vitro, consistent with direct EF-RNA interaction. Set1 recruitment to genes in vivo depends on its RNA recognition motifs (RRMs). These results strongly suggest that nascent RNA contributes to EF recruitment to transcribing Pol II. We propose that EF-RNA interactions facilitate assembly of the elongation complex on transcribed genes when RNA emerges from Pol II, and that loss of EF-RNA interactions upon RNA cleavage at the polyadenylation site triggers disassembly of the elongation complex.

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