The Experts below are selected from a list of 129 Experts worldwide ranked by ideXlab platform

Maurice S Swanson - One of the best experts on this subject based on the ideXlab platform.

  • characterization of nuclear Polyadenylated RNA binding proteins in saccharomyces cerevisiae
    Journal of Cell Biology, 1994
    Co-Authors: Scott M Wilson, Michael R Paddy, Kshama V Datar, Jason R Swedlow, Maurice S Swanson
    Abstract:

    To study the functions of heterogeneous nuclear ribonucleoproteins (hnRNPs), we have characterized nuclear Polyadenylated RNA-binding (Nab) proteins from Saccharomyces cerevisiae. Nab1p, Nab2p, and Nab3p were isolated by a method which uses UV light to cross-link proteins directly bound to poly(A)+ RNA in vivo. We have previously characterized Nab2p, and demonstrated that it is structurally related to human hnRNPs. Here we report that Nab1p is identical to the Np13p/Nop3p protein recently implicated in both nucleocytoplasmic protein shuttling and pre-rRNA processing, and characterize a new nuclear Polyadenylated RNA-binding protein, Nab3p. The intranuclear distributions of the Nab proteins were analyzed by three-dimensional immunofluorescence optical microscopy. All three Nab proteins are predominantly localized within the nucleoplasm in a pattern similar to the distribution of hnRNPs in human cells. The NAB3 gene is essential for cell viability and encodes an acidic ribonucleoprotein. Loss of Nab3p by growth of a GAL::nab3 mutant strain in glucose results in a decrease in the amount of mature ACT1, CYH2, and TPI1 mRNAs, a concomitant accumulation of unspliced ACT1 pre-mRNA, and an increase in the ratio of unspliced CYH2 pre-mRNA to mRNA. These results suggest that the Nab proteins may be required for packaging pre-mRNAs into ribonucleoprotein structures amenable to efficient nuclear RNA processing.

  • nab2 a yeast nuclear Polyadenylated RNA binding protein essential for cell viability
    Molecular and Cellular Biology, 1993
    Co-Authors: Jessica Anderson, Scott M Wilson, Kshama V Datar, Maurice S Swanson
    Abstract:

    these proteins byusing acombined biochemical andgenetic approach, wehaveisolated nuclear Polyadenylated RNA-binding (NAB)proteins fromSaccharomyces cerevisiae. Living yeast cells wereirradiated withUVlight tocovalently cross-link proteins intimately associated withRNA invivo. Polyadenylated RNAswerethen selectively purified, andthecovalent RNA-protein complexes wereusedtoelicit antibodies inmice. Both monoclonal andpolyclonal antibodies whichdetect avariety ofNAB proteins wereprepared. Herewe characterize oneoftheseproteins, NAB2.NAB2isoneofthemajorproteins associated withnuclear Polyadenylated RNA invivo, asdetected byUV light-induced cross-linking. Cellular immunofluorescence, using bothmonoclonal andpolyclonal antibodies, demonstrates thattheNAB2protein islocalized within the nucleus. Thededuced primary structure ofNAB2indicates that itiscomposed ofatleast twodistinct types of RNA-binding motifs: (i)anRGG boxrecently described ina variety ofheterogeneous nuclear RNA-, pre-rRNA-, mRNA-,andsmall nucleolar RNA-binding proteins and(ii) CCCHmotif repeats related tothe zinc-binding motifs ofthelargest subunit ofRNA polymerases I,II,andIII. Invitro RNA homopolymer/ single-stranded DNAbinding studies indicate that although boththeRGGboxandCCCHmotifs bindpoly(G), poly(U), andsingle-stranded DNA,theCCCHmotifs also bindtopoly(A). NAB2islocated onchromosome VII within acluster ofribonucleoprotein genes, anditsexpression isessential forcell growth. Geneexpression isregulated atmultiple levels following theinitiation oftranscription byRNA polymerase II.Nascentpre-mRNAtranscripts areextensively modified to generate mRNAs (59). Thesemodifications, allofwhich occurinthenucleus, mayinclude 5'-end capping (46, 52), 3'-end cleavage andpolyadenylation (64), splicing (27, 53), andmodification ofindividual bases(16). Allofthese activities occurwhilepre-mRNAs areassociated witha setof nuclear factors whichmayinclude bothheterogeneous nuclear ribonucleoproteins

Jessica Anderson - One of the best experts on this subject based on the ideXlab platform.

  • nab2 a yeast nuclear Polyadenylated RNA binding protein essential for cell viability
    Molecular and Cellular Biology, 1993
    Co-Authors: Jessica Anderson, Scott M Wilson, Kshama V Datar, Maurice S Swanson
    Abstract:

    these proteins byusing acombined biochemical andgenetic approach, wehaveisolated nuclear Polyadenylated RNA-binding (NAB)proteins fromSaccharomyces cerevisiae. Living yeast cells wereirradiated withUVlight tocovalently cross-link proteins intimately associated withRNA invivo. Polyadenylated RNAswerethen selectively purified, andthecovalent RNA-protein complexes wereusedtoelicit antibodies inmice. Both monoclonal andpolyclonal antibodies whichdetect avariety ofNAB proteins wereprepared. Herewe characterize oneoftheseproteins, NAB2.NAB2isoneofthemajorproteins associated withnuclear Polyadenylated RNA invivo, asdetected byUV light-induced cross-linking. Cellular immunofluorescence, using bothmonoclonal andpolyclonal antibodies, demonstrates thattheNAB2protein islocalized within the nucleus. Thededuced primary structure ofNAB2indicates that itiscomposed ofatleast twodistinct types of RNA-binding motifs: (i)anRGG boxrecently described ina variety ofheterogeneous nuclear RNA-, pre-rRNA-, mRNA-,andsmall nucleolar RNA-binding proteins and(ii) CCCHmotif repeats related tothe zinc-binding motifs ofthelargest subunit ofRNA polymerases I,II,andIII. Invitro RNA homopolymer/ single-stranded DNAbinding studies indicate that although boththeRGGboxandCCCHmotifs bindpoly(G), poly(U), andsingle-stranded DNA,theCCCHmotifs also bindtopoly(A). NAB2islocated onchromosome VII within acluster ofribonucleoprotein genes, anditsexpression isessential forcell growth. Geneexpression isregulated atmultiple levels following theinitiation oftranscription byRNA polymerase II.Nascentpre-mRNAtranscripts areextensively modified to generate mRNAs (59). Thesemodifications, allofwhich occurinthenucleus, mayinclude 5'-end capping (46, 52), 3'-end cleavage andpolyadenylation (64), splicing (27, 53), andmodification ofindividual bases(16). Allofthese activities occurwhilepre-mRNAs areassociated witha setof nuclear factors whichmayinclude bothheterogeneous nuclear ribonucleoproteins

Richard Stefl - One of the best experts on this subject based on the ideXlab platform.

  • recognition of transcription termination signal by the nuclear Polyadenylated RNA binding nab 3 protein
    Journal of Biological Chemistry, 2011
    Co-Authors: Fruzsina Hobor, Roberto Pergoli, Karel Kubicek, Dominika Hrossova, Veronika Bacikova, Michal Zimmermann, Josef Pasulka, Ctirad Hofr, Stepanka Vanacova, Richard Stefl
    Abstract:

    Non-coding RNA polymerase II transcripts are processed by the poly(A)-independent termination pathway that requires the Nrd1 complex. The Nrd1 complex includes two RNA-binding proteins, the nuclear Polyadenylated RNA-binding (Nab) 3 and the nuclear pre-mRNA down-regulation (Nrd) 1 that bind their specific termination elements. Here we report the solution structure of the RNA-recognition motif (RRM) of Nab3 in complex with a UCUU oligonucleotide, representing the Nab3 termination element. The structure shows that the first three nucleotides of UCUU are accommodated on the β-sheet surface of Nab3 RRM, but reveals a sequence-specific recognition only for the central cytidine and uridine. The specific contacts we identified are important for binding affinity in vitro as well as for yeast viability. Furthermore, we show that both RNA-binding motifs of Nab3 and Nrd1 alone bind their termination elements with a weak affinity. Interestingly, when Nab3 and Nrd1 form a heterodimer, the affinity to RNA is significantly increased due to the cooperative binding. These findings are in accordance with the model of their function in the poly(A) independent termination, in which binding to the combined and/or repetitive termination elements elicits efficient termination.

Scott M Wilson - One of the best experts on this subject based on the ideXlab platform.

  • characterization of nuclear Polyadenylated RNA binding proteins in saccharomyces cerevisiae
    Journal of Cell Biology, 1994
    Co-Authors: Scott M Wilson, Michael R Paddy, Kshama V Datar, Jason R Swedlow, Maurice S Swanson
    Abstract:

    To study the functions of heterogeneous nuclear ribonucleoproteins (hnRNPs), we have characterized nuclear Polyadenylated RNA-binding (Nab) proteins from Saccharomyces cerevisiae. Nab1p, Nab2p, and Nab3p were isolated by a method which uses UV light to cross-link proteins directly bound to poly(A)+ RNA in vivo. We have previously characterized Nab2p, and demonstrated that it is structurally related to human hnRNPs. Here we report that Nab1p is identical to the Np13p/Nop3p protein recently implicated in both nucleocytoplasmic protein shuttling and pre-rRNA processing, and characterize a new nuclear Polyadenylated RNA-binding protein, Nab3p. The intranuclear distributions of the Nab proteins were analyzed by three-dimensional immunofluorescence optical microscopy. All three Nab proteins are predominantly localized within the nucleoplasm in a pattern similar to the distribution of hnRNPs in human cells. The NAB3 gene is essential for cell viability and encodes an acidic ribonucleoprotein. Loss of Nab3p by growth of a GAL::nab3 mutant strain in glucose results in a decrease in the amount of mature ACT1, CYH2, and TPI1 mRNAs, a concomitant accumulation of unspliced ACT1 pre-mRNA, and an increase in the ratio of unspliced CYH2 pre-mRNA to mRNA. These results suggest that the Nab proteins may be required for packaging pre-mRNAs into ribonucleoprotein structures amenable to efficient nuclear RNA processing.

  • nab2 a yeast nuclear Polyadenylated RNA binding protein essential for cell viability
    Molecular and Cellular Biology, 1993
    Co-Authors: Jessica Anderson, Scott M Wilson, Kshama V Datar, Maurice S Swanson
    Abstract:

    these proteins byusing acombined biochemical andgenetic approach, wehaveisolated nuclear Polyadenylated RNA-binding (NAB)proteins fromSaccharomyces cerevisiae. Living yeast cells wereirradiated withUVlight tocovalently cross-link proteins intimately associated withRNA invivo. Polyadenylated RNAswerethen selectively purified, andthecovalent RNA-protein complexes wereusedtoelicit antibodies inmice. Both monoclonal andpolyclonal antibodies whichdetect avariety ofNAB proteins wereprepared. Herewe characterize oneoftheseproteins, NAB2.NAB2isoneofthemajorproteins associated withnuclear Polyadenylated RNA invivo, asdetected byUV light-induced cross-linking. Cellular immunofluorescence, using bothmonoclonal andpolyclonal antibodies, demonstrates thattheNAB2protein islocalized within the nucleus. Thededuced primary structure ofNAB2indicates that itiscomposed ofatleast twodistinct types of RNA-binding motifs: (i)anRGG boxrecently described ina variety ofheterogeneous nuclear RNA-, pre-rRNA-, mRNA-,andsmall nucleolar RNA-binding proteins and(ii) CCCHmotif repeats related tothe zinc-binding motifs ofthelargest subunit ofRNA polymerases I,II,andIII. Invitro RNA homopolymer/ single-stranded DNAbinding studies indicate that although boththeRGGboxandCCCHmotifs bindpoly(G), poly(U), andsingle-stranded DNA,theCCCHmotifs also bindtopoly(A). NAB2islocated onchromosome VII within acluster ofribonucleoprotein genes, anditsexpression isessential forcell growth. Geneexpression isregulated atmultiple levels following theinitiation oftranscription byRNA polymerase II.Nascentpre-mRNAtranscripts areextensively modified to generate mRNAs (59). Thesemodifications, allofwhich occurinthenucleus, mayinclude 5'-end capping (46, 52), 3'-end cleavage andpolyadenylation (64), splicing (27, 53), andmodification ofindividual bases(16). Allofthese activities occurwhilepre-mRNAs areassociated witha setof nuclear factors whichmayinclude bothheterogeneous nuclear ribonucleoproteins

Kshama V Datar - One of the best experts on this subject based on the ideXlab platform.

  • characterization of nuclear Polyadenylated RNA binding proteins in saccharomyces cerevisiae
    Journal of Cell Biology, 1994
    Co-Authors: Scott M Wilson, Michael R Paddy, Kshama V Datar, Jason R Swedlow, Maurice S Swanson
    Abstract:

    To study the functions of heterogeneous nuclear ribonucleoproteins (hnRNPs), we have characterized nuclear Polyadenylated RNA-binding (Nab) proteins from Saccharomyces cerevisiae. Nab1p, Nab2p, and Nab3p were isolated by a method which uses UV light to cross-link proteins directly bound to poly(A)+ RNA in vivo. We have previously characterized Nab2p, and demonstrated that it is structurally related to human hnRNPs. Here we report that Nab1p is identical to the Np13p/Nop3p protein recently implicated in both nucleocytoplasmic protein shuttling and pre-rRNA processing, and characterize a new nuclear Polyadenylated RNA-binding protein, Nab3p. The intranuclear distributions of the Nab proteins were analyzed by three-dimensional immunofluorescence optical microscopy. All three Nab proteins are predominantly localized within the nucleoplasm in a pattern similar to the distribution of hnRNPs in human cells. The NAB3 gene is essential for cell viability and encodes an acidic ribonucleoprotein. Loss of Nab3p by growth of a GAL::nab3 mutant strain in glucose results in a decrease in the amount of mature ACT1, CYH2, and TPI1 mRNAs, a concomitant accumulation of unspliced ACT1 pre-mRNA, and an increase in the ratio of unspliced CYH2 pre-mRNA to mRNA. These results suggest that the Nab proteins may be required for packaging pre-mRNAs into ribonucleoprotein structures amenable to efficient nuclear RNA processing.

  • nab2 a yeast nuclear Polyadenylated RNA binding protein essential for cell viability
    Molecular and Cellular Biology, 1993
    Co-Authors: Jessica Anderson, Scott M Wilson, Kshama V Datar, Maurice S Swanson
    Abstract:

    these proteins byusing acombined biochemical andgenetic approach, wehaveisolated nuclear Polyadenylated RNA-binding (NAB)proteins fromSaccharomyces cerevisiae. Living yeast cells wereirradiated withUVlight tocovalently cross-link proteins intimately associated withRNA invivo. Polyadenylated RNAswerethen selectively purified, andthecovalent RNA-protein complexes wereusedtoelicit antibodies inmice. Both monoclonal andpolyclonal antibodies whichdetect avariety ofNAB proteins wereprepared. Herewe characterize oneoftheseproteins, NAB2.NAB2isoneofthemajorproteins associated withnuclear Polyadenylated RNA invivo, asdetected byUV light-induced cross-linking. Cellular immunofluorescence, using bothmonoclonal andpolyclonal antibodies, demonstrates thattheNAB2protein islocalized within the nucleus. Thededuced primary structure ofNAB2indicates that itiscomposed ofatleast twodistinct types of RNA-binding motifs: (i)anRGG boxrecently described ina variety ofheterogeneous nuclear RNA-, pre-rRNA-, mRNA-,andsmall nucleolar RNA-binding proteins and(ii) CCCHmotif repeats related tothe zinc-binding motifs ofthelargest subunit ofRNA polymerases I,II,andIII. Invitro RNA homopolymer/ single-stranded DNAbinding studies indicate that although boththeRGGboxandCCCHmotifs bindpoly(G), poly(U), andsingle-stranded DNA,theCCCHmotifs also bindtopoly(A). NAB2islocated onchromosome VII within acluster ofribonucleoprotein genes, anditsexpression isessential forcell growth. Geneexpression isregulated atmultiple levels following theinitiation oftranscription byRNA polymerase II.Nascentpre-mRNAtranscripts areextensively modified to generate mRNAs (59). Thesemodifications, allofwhich occurinthenucleus, mayinclude 5'-end capping (46, 52), 3'-end cleavage andpolyadenylation (64), splicing (27, 53), andmodification ofindividual bases(16). Allofthese activities occurwhilepre-mRNAs areassociated witha setof nuclear factors whichmayinclude bothheterogeneous nuclear ribonucleoproteins