scholarly journals Immunopurification of heterogeneous nuclear ribonucleoprotein particles reveals an assortment of RNA-binding proteins.

1988 ◽  
Vol 2 (2) ◽  
pp. 215-227 ◽  
Author(s):  
S Pinol-Roma ◽  
Y D Choi ◽  
M J Matunis ◽  
G Dreyfuss
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Ribonucleoprotein Particles ◽  
Nuclear Ribonucleoprotein

scholarly journals Identification of two RNA-binding proteins in Balbiani ring premessenger ribonucleoprotein granules and presence of these proteins in specific subsets of heterogeneous nuclear ribonucleoprotein particles.

1996 ◽  
Vol 16 (4) ◽  
pp. 1425-1435 ◽  
Author(s):  
Wurtz-T ◽  
E Kiseleva ◽  
G Nacheva ◽  
A Alzhanova-Ericcson ◽  
A Rosén ◽  
...  
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Affinity Column ◽  
Balbiani Ring ◽  
Western Blots ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Ribonucleoprotein Particles ◽  
Specific Subset ◽  
Nuclear Ribonucleoprotein

Balbiani ring (BR) granules are premessenger ribonucleoprotein particles (RNPs) generated in giant chromosomal puffs, the BRs, in the larval salivary glands of the dipteran chironomus tentans. Monoclonal antibodies were raised against nuclear proteins collected on a single-stranded-DNA-agarose affinity column, and two of them were used to identify RNA-binding proteins in BR granules. First, in Western blots (immunoblots), one of the antibodies recognized a 36-kDa protein and the other recognized a 45-KDa protein. Second, both antibodies bound to the BRs in immunocytological experiments. It was shown in cross-linking experiments that the two proteins are associated with heterogeneous nuclear RNP (hnRNP) complexes extracted from C. tentans nuclei. By immunoelectron microscopy of isolated and partly unfolded BR RNPs, it was specifically demonstrated that the BR granules contain the two proteins and, in addition, that both proteins are distributed frequently along the RNP fiber of the particles. Thus, the 36- and 45-KDa proteins are likely to be abundant, RNA-binding proteins in the BR particles. To elucidate to what extent the two proteins are also present in other hnRNPs, we studied the binding of the antibodies to chromosomal puffs in general. It was observed that many puffs in addition to the BRs harbor the two proteins, but there are also puffs containing only one of the components, either the 36- or the 45-kDa protein. We conclude that the two proteins are not randomly bound to all hnRNPs but that each of them seems to be linked to a specific subset of the particles.

scholarly journals Myoparr-Associated and -Independent Multiple Roles of Heterogeneous Nuclear Ribonucleoprotein K during Skeletal Muscle Cell Differentiation

2021 ◽  
Vol 23 (1) ◽  
pp. 108
Author(s):  
Keisuke Hitachi ◽  
Yuri Kiyofuji ◽  
Masashi Nakatani ◽  
Kunihiro Tsuchida
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Myogenic Differentiation ◽  
Multiple Roles ◽  
Cell Physiology ◽  
Transcriptional Level ◽  
Multiple Functions ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Nuclear Ribonucleoprotein

RNA-binding proteins (RBPs) regulate cell physiology via the formation of ribonucleic-protein complexes with coding and non-coding RNAs. RBPs have multiple functions in the same cells; however, the precise mechanism through which their pleiotropic functions are determined remains unknown. In this study, we revealed the multiple inhibitory functions of heterogeneous nuclear ribonucleoprotein K (hnRNPK) for myogenic differentiation. We first identified hnRNPK as a lncRNA Myoparr binding protein. Gain- and loss-of-function experiments showed that hnRNPK repressed the expression of myogenin at the transcriptional level. The hnRNPK-binding region of Myoparr was required to repress myogenin expression. Moreover, hnRNPK repressed the expression of a set of genes coding for aminoacyl-tRNA synthetases in a Myoparr-independent manner. Mechanistically, hnRNPK regulated the eIF2α/Atf4 pathway, one branch of the intrinsic pathways of the endoplasmic reticulum sensors, in differentiating myoblasts. Thus, our findings demonstrate that hnRNPK plays lncRNA-associated and -independent multiple roles during myogenic differentiation, indicating that the analysis of lncRNA-binding proteins will be useful for elucidating both the physiological functions of lncRNAs and the multiple functions of RBPs.

Classification and purification of proteins of heterogeneous nuclear ribonucleoprotein particles by RNA-binding specificities

1988 ◽  
Vol 8 (5) ◽  
pp. 2237-2241 ◽  
Author(s):  
M S Swanson ◽  
G Dreyfuss
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Binding Affinities ◽  
High Binding ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Hnrnp Proteins ◽  
Hnrnp C ◽  
One Step ◽  
Nuclear Ribonucleoprotein ◽  
Very High

Several proteins of heterogeneous nuclear ribonucleoprotein (hnRNP) particles display very high binding affinities for different ribonucleotide homopolymers. The specificity of some of these proteins at high salt concentrations and in the presence of heparin allows for their rapid one-step purification from HeLa nucleoplasm. We show that the hnRNP C proteins are poly(U)-binding proteins and compare their specificity to that of the previously described cytoplasmic poly(A)-binding protein. These findings provide a useful tool for the classification and purification of hnRNP proteins from various tissues and organisms and indicate that different hnRNP proteins have different RNA-binding specificities.

Primary structure of human nuclear ribonucleoprotein particle C proteins: conservation of sequence and domain structures in heterogeneous nuclear RNA, mRNA, and pre-rRNA-binding proteins

1987 ◽  
Vol 7 (5) ◽  
pp. 1731-1739
Author(s):  
M S Swanson ◽  
T Y Nakagawa ◽  
K LeVan ◽  
G Dreyfuss
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Binding Protein ◽  
Consensus Sequence ◽  
Amino Terminus ◽  
Carboxy Terminus ◽  
Hnrnp Proteins ◽  
C Proteins ◽  
Nuclear Ribonucleoprotein

In the eucaryotic nucleus, heterogeneous nuclear RNAs exist in a complex with a specific set of proteins to form heterogeneous nuclear ribonucleoprotein particles (hnRNPs). The C proteins, C1 and C2, are major constituents of hnRNPs and appear to play a role in RNA splicing as suggested by antibody inhibition and immunodepletion experiments. With the use of a previously described partial cDNA clone as a hybridization probe, full-length cDNAs for the human C proteins were isolated. All of the cDNAs isolated hybridized to two poly(A)+ RNAs of 1.9 and 1.4 kilobases (kb). DNA sequencing of a cDNA clone for the 1.9-kb mRNA (pHC12) revealed a single open reading frame of 290 amino acids coding for a protein of 31,931 daltons and two polyadenylation signals, AAUAAA, approximately 400 base pairs apart in the 3' untranslated region of the mRNA. DNA sequencing of a clone corresponding to the 1.4-kb mRNA (pHC5) indicated that the sequence of this mRNA is identical to that of the 1.9-kb mRNA up to the first polyadenylation signal which it uses. Both mRNAs therefore have the same coding capacity and are probably transcribed from a single gene. Translation in vitro of the 1.9-kb mRNA selected by hybridization with a 3'-end subfragment of pHC12 demonstrated that it by itself can direct the synthesis of both C1 and C2. The difference between the C1 and C2 proteins which results in their electrophoretic separation is not known, but most likely one of them is generated from the other posttranslationally. Since several hnRNP proteins appeared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis as multiple antigenically related polypeptides, this raises the possibility that some of these other groups of hnRNP proteins are also each produced from a single mRNA. The predicted amino acid sequence of the protein indicates that it is composed of two distinct domains: an amino terminus that contains what we have recently described as a RNP consensus sequence, which is the putative RNA-binding site, and a carboxy terminus that is very negatively charged, contains no aromatic amino acids or prolines, and contains a putative nucleoside triphosphate-binding fold, as well as a phosphorylation site for casein kinase type II. The RNP consensus sequence was also found in the yeast poly(A)-binding protein (PABP), the heterogeneous nuclear RNA-binding proteins A1 and A2, and the pre-rRNA binding protein C23. All of these proteins are also composed of at least two distinct domains: an amino terminus, which possesses one or more RNP consensus sequences, and a carboxy terminus, which is unique to each protein, being very acidic in the C proteins and rich in glycine in A1, and C23 and rich in proline in the poly(A)-binding protein. These findings suggest that the amino terminus of these proteins possesses a highly conserved RNA-binding domain, whereas the carboxy terminus contains a region essential to the unique function and interactions of each of the RNA-binding proteins.

scholarly journals Recognition of subsets of the mammalian A/B-type core heterogeneous nuclear ribonucleoprotein polypeptides by novel autoantibodies

1996 ◽  
Vol 320 (3) ◽  
pp. 761-767 ◽  
Author(s):  
Amalia DANGLI ◽  
Angeliki PLOMARITOGLOU ◽  
Efrosini BOUTOU ◽  
Neratzoula VASSILIADOU ◽  
Haralampos M. MOUTSOPOULOS ◽  
...  
Keyword(s):  
Rna Binding ◽  
Rna Binding Proteins ◽  
Peptide Mapping ◽  
Protein A ◽  
Major Protein ◽  
Protein Species ◽  
Two Dimensional Gel Electrophoresis ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Core Proteins ◽  
Nuclear Ribonucleoprotein

The structurally related A/B-type core heterogeneous nuclear ribonucleoprotein (hnRNP) polypeptides of 34–39 kDa (A1, A2, B1 and B2) belong to a family of RNA-binding proteins that are major components of 40 S hnRNP complexes. By two-dimensional gel electrophoresis and peptide mapping analysis we compared each member of the A/B-type core proteins in the human and rat liver cells. This comparison revealed the unique presence in rat cells of major protein species, referred to as mBx polypeptides, that appeared as three charge isoforms at a position corresponding to the minor HeLa B1b protein spot. In addition, clear differences in the ratios of the A1 polypeptide to the A1b isoform were observed. The detection, in sera of patients with rheumatic autoimmune diseases, of two novel autoantibody specificities, one recognizing solely B2 protein and the second both the B2 and mBx polypeptides, helped to identify mBx proteins as new A/B-type hnRNP components, immunologically related to B2 protein. A common immunoreactive V8 protease peptide of approx. 17 kDa has been identified in B2 and mBx hnRNP polypeptides. mBx protein species are identified in cells of murine origin, and have a ubiquitous tissue distribution and developmental appearance.

scholarly journals Classification and purification of proteins of heterogeneous nuclear ribonucleoprotein particles by RNA-binding specificities.

1988 ◽  
Vol 8 (5) ◽  
pp. 2237-2241 ◽  
Author(s):  
M S Swanson ◽  
G Dreyfuss
Keyword(s):  
Binding Proteins ◽  
Rna Binding ◽  
Binding Affinities ◽  
High Binding ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Hnrnp Proteins ◽  
Hnrnp C ◽  
One Step ◽  
Nuclear Ribonucleoprotein ◽  
Very High

Several proteins of heterogeneous nuclear ribonucleoprotein (hnRNP) particles display very high binding affinities for different ribonucleotide homopolymers. The specificity of some of these proteins at high salt concentrations and in the presence of heparin allows for their rapid one-step purification from HeLa nucleoplasm. We show that the hnRNP C proteins are poly(U)-binding proteins and compare their specificity to that of the previously described cytoplasmic poly(A)-binding protein. These findings provide a useful tool for the classification and purification of hnRNP proteins from various tissues and organisms and indicate that different hnRNP proteins have different RNA-binding specificities.

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