scholarly journals Identification of TINO

2004 ◽  
Vol 279 (19) ◽  
pp. 20154-20166 ◽  
Author(s):  
Martino Donnini ◽  
Andrea Lapucci ◽  
Laura Papucci ◽  
Ewa Witort ◽  
Alain Jacquier ◽  
...  
Keyword(s):  
Gene Expression ◽  
Binding Proteins ◽  
Nucleic Acid Binding ◽  
Cis Acting ◽  
Ciona Savignyi ◽  
Amino Terminal ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Gene Expression Control ◽  
Nuclear Ribonucleoprotein ◽  
Mrna Binding

Modulation of mRNA stability by regulatory cis-acting AU-rich elements (AREs) and ARE-binding proteins is an important posttranscriptional mechanism of gene expression control. We previously demonstrated that the 3′-untranslated region ofBCL-2mRNA contains an ARE that accounts for rapidBCL-2down-regulation in response to apoptotic stimuli. We also demonstrated that theBCL-2ARE core interacts with a number of ARE-binding proteins, one of which is AU-rich factor 1/heterogeneous nuclear ribonucleoprotein D, known for its interaction with mRNA elements of others genes. In an attempt to search for otherBCL-2mRNA-binding proteins, we used the yeast RNA three-hybrid system assay and identified a novel human protein that interacts withBCL-2ARE. We refer to it as TINO. The predicted protein sequence of TINO reveals two amino-terminal heterogeneous nuclear ribonucleoprotein K homology motifs for nucleic acid binding and a carboxyl-terminal RING domain, endowed with a putative E3 ubiquitin-protein ligase activity. In addition the novel protein is evolutionarily conserved; the two following orthologous proteins have been identified with protein-protein BLAST: posterior end mark-3 (PEM-3) ofCiona savignyiand muscle excess protein-3 (MEX-3) ofCaenorhabditis elegans. Upon binding, TINO destabilizes a chimeric reporter construct containing theBCL-2ARE sequence, revealing a negative regulatory action onBCL-2gene expression at the posttranscriptional level.

scholarly journals A proteomics approach for the identification of nucleophosmin and heterogeneous nuclear ribonucleoprotein C1/C2 as chromatin-binding proteins in response to DNA double-strand breaks

2005 ◽  
Vol 388 (1) ◽  
pp. 7-15 ◽  
Author(s):  
Seung Yun LEE ◽  
Ji-Hye PARK ◽  
Sungsu KIM ◽  
Eun-Jung PARK ◽  
Yungdae YUN ◽  
...  
Keyword(s):  
Dna Damage ◽  
Dna Repair ◽  
Binding Proteins ◽  
Double Strand Breaks ◽  
Nuclear Proteins ◽  
Chromatin Binding ◽  
Strand Breaks ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Proteomics Approach ◽  
Nuclear Ribonucleoprotein

Double-strand breaks (DSBs) of chromosomal DNA trigger the cellular response that activates the pathways for DNA repair and cell-cycle checkpoints, and sometimes the pathways leading to cell death if the damage is too severe to be tolerated. Evidence indicates that, upon generation of DNA DSBs, many nuclear proteins that are involved in DNA repair and checkpoints are recruited to chromatin around the DNA lesions. In the present study we used a proteomics approach to identify DNA-damage-induced chromatin-binding proteins in a systematic way. Two-dimensional gel analysis for protein extracts of chromatin from DNA-damage-induced and control HeLa cells identified four proteins as the candidates for DNA-damage-induced chromatin-binding proteins. MALDI–TOF (matrix-assisted laser-desorption ionization–time-of-flight) MS analysis identified these proteins to be NPM (nucleophosmin), hnRNP (heterogeneous nuclear ribonucleoprotein) C1, hnRNP C2 and 37-kDa laminin-receptor precursor, and the identity of these proteins was further confirmed by immunoblot analysis with specific antibodies. We then demonstrated with chromatin-binding assays that NPM and hnRNP C1/C2, the abundant nuclear proteins with pleiotropic functions, indeed bind to chromatin in a DNA-damage-dependent manner, implicating these proteins in DNA repair and/or damage response. Immunofluorescence experiments showed that NPM, normally present in the nucleoli, is mobilized into the nucleoplasm after DNA damage, and that neither NPM nor hnRNP C1/C2 is actively recruited to the sites of DNA breaks. These results suggest that NPM and hnRNP C1/C2 may function at the levels of the global context of chromatin, rather than by specifically targeting the broken DNA.

scholarly journals Requirement of Heterogeneous Nuclear Ribonucleoprotein C for BRCA Gene Expression and Homologous Recombination

PLoS ONE ◽  
2013 ◽  
Vol 8 (4) ◽  
pp. e61368 ◽  
Author(s):  
Rachel W. Anantha ◽  
Allen L. Alcivar ◽  
Jianglin Ma ◽  
Hong Cai ◽  
Srilatha Simhadri ◽  
...  
Keyword(s):  
Gene Expression ◽  
Homologous Recombination ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Brca Gene ◽  
Nuclear Ribonucleoprotein

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.

scholarly journals Cell cycle-regulated phosphorylation of the pre-mRNA-binding (heterogeneous nuclear ribonucleoprotein) C proteins.

1993 ◽  
Vol 13 (9) ◽  
pp. 5762-5770 ◽  
Author(s):  
S Piñol-Roma ◽  
G Dreyfuss
Keyword(s):  
Cell Cycle ◽  
Gel Electrophoresis ◽  
Kinase Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Heterogeneous Nuclear Ribonucleoprotein ◽  
Hnrnp C ◽  
C Proteins ◽  
Nuclear Ribonucleoprotein ◽  
Mrna Binding

Heterogeneous nuclear ribonucleoprotein (hnRNP) complexes, the structures that contain heterogeneous nuclear RNA and its associated proteins, constitute one of the most abundant components of the eukaryotic nucleus. hnRNPs appear to play important roles in the processing, and possibly also in the transport, of mRNA. hnRNP C proteins (C1, M(r) of 41,000; C2, M(r) of 43,000 [by sodium dodecyl sulfate-polyacrylamide gel electrophoresis]) are among the most abundant pre-mRNA-binding proteins, and they bind tenaciously to sequences relevant to pre-mRNA processing, including the polypyrimidine stretch of introns (when it is uridine rich). C proteins are found in the nucleus during the interphase, but during mitosis they disperse throughout the cell. They have been shown previously to be phosphorylated in vivo, and they can be phosphorylated in vitro by a casein kinase type II. We have identified and partially purified at least two additional C protein kinases. One of these, termed Cs kinase, caused a distinct mobility shift of C proteins on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. These phosphorylated C proteins, the Cs proteins, were the prevalent forms of C proteins during mitosis, and Cs kinase activity was also increased in extracts prepared from mitotic cells. Thus, hnRNP C proteins undergo cell cycle-dependent phosphorylation by a cell cycle-regulated protein kinase. Cs kinase activity appears to be distinct from the well-characterized mitosis-specific histone H1 kinase activity. Several additional hnRNP proteins are also phosphorylated during mitosis and are thus also potential substrates for Cs kinase. These novel phosphorylations may be important in regulating the assembly and disassembly of hnRNP complexes and in the function or cellular localization of RNA-binding proteins.

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