An integrated approach in the discovery and characterization of a novel nuclear protein over‐expressed in liver and pancreatic tumors

Choong, Meng Ling; Tan, Li; Lo, Siaw Ling; Ren, Ee Chee; Ou, Keli; Ong, Shao En; Liang, Rosa C. M. Y.; Seow, Teck Keong; Chung, Maxey C. M.

doi:10.1016/s0014-5793(01)02409-7

Cited by 37 publications

(40 citation statements)

References 37 publications

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“…Interestingly, our in silico analysis revealed that the human ortholog of Tho1 is likely the Hcc-1 protein (see Fig. S2 in the supplemental material), which was identified as a highly expressed protein in human hepatocarcinoma and which has been shown in two-hybrid assays to bind the two DEAD box putative RNA helicases, hSUB2/UAP56/BAT1 and DDX39 (12,35).…”

Section: Resultsmentioning

confidence: 98%

“…The putative structural homolog of Tho1 in humans is a nuclear-matrix protein, Hcc-1 (see Fig. S2 in the supplemental material), which has been shown in two-hybrid assays to bind the two DEAD box putative RNA helicases, hSUB2/UAP56/BAT1 and DDX39 (12,35). Whether Tho1 might interact with RNAdependent ATPases important in the assembly of export-competent mRNPs is a possibility to be explored.…”

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confidence: 99%

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Tho1, a Novel hnRNP, and Sub2 Provide Alternative Pathways for mRNP Biogenesis in Yeast THO Mutants

Jimeno

Luna

García-Rubio

et al. 2006

Molecular and Cellular Biology

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THO is a protein complex that functions in cotranscriptional mRNP formation. Yeast THO1 and SUB2 (Saccharomyces cerevisiae) were identified as multicopy suppressors of the expression defects of the hpr1⌬ mutant of THO. Here we show that multicopy THO1 suppresses the mRNA accumulation and export defects and the hyperrecombination phenotype of THO mutants but not those of sub2⌬, thp1⌬, or spt4⌬. Similarly, Sub2 overexpression suppresses the RNA export defect of hpr1⌬. Tho1 is a conserved RNA binding nuclear protein that specifically binds to transcribed chromatin in a THO-and RNA-dependent manner and genetically interacts with the shuttling hnRNP Nab2. The ability of Tho1 to suppress hpr1⌬ resides in its C-terminal half, which contains the RNA binding activity and is located after a SAP/SAF (scaffold-associated protein/scaffoldassociated factor) domain. Altogether, these results suggest that Tho1 is an hnRNP that, similarly to Sub2, assembles onto the nascent mRNA during transcription and participates in mRNP biogenesis and export. Overexpression of Tho1 or Sub2 may provide alternative ways for mRNP formation and export in the absence of a functional THO complex.Transcription is a central cellular function that occurs in the nucleus of eukaryotic cells in coordination with other nuclear processes. RNA polymerase II (RNAPII)-driven transcription takes place in tight association with different mRNA processing steps (46, 59). Indeed, a number of important proteins involved in mRNA processing, such as the capping enzymes, splicing factors, and the cleavage and polyadenylation stimulatory factor responsible for recognizing the poly(A) ϩ signal, are loaded onto the nascent mRNA by interacting with the C-terminal domain (CTD) of the RNAPII (43). Thus, in cell extracts, a recombinant CTD stimulates poly(A) site cleavage and mRNA splicing (22, 23) and influences 3Ј-end formation and capping of mRNAs (50, 55). The result of the combined action of molecular processes is a mature mRNA-protein (mRNP) particle proficient for nuclear export. Any failure compromising the formation of an export-proficient mRNP would likely trigger mRNA degradation by the nuclear exosome (28, 54), a process which may also occur cotranscriptionally as shown in Drosophila spp. (6). The nuclear integration of the different processes taking place from transcription to mRNA export was recently observed at the cellular level by the nuclear pore colocalization of actively transcribed GAL genes (8).An intriguing connection of mRNP biogenesis with other nuclear processes is that observed with genetic stability. Even though there is accumulated evidence for the stimulation of both mutation and recombination by transcription, the functional and physical interconnection between mRNP biogenesis and genetic instability comes from studies with the THO complex of Saccharomyces cerevisiae (2, 3). THO is a four-protein complex composed of stoichiometric amounts of Tho2, Hpr1, Mft1, and Thp2 (10). Null mutations of any component of THO lead to similar phenotypes of t...

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Section: Resultsmentioning

confidence: 98%

mentioning

confidence: 99%

Tho1, a Novel hnRNP, and Sub2 Provide Alternative Pathways for mRNP Biogenesis in Yeast THO Mutants

Jimeno

Luna

García-Rubio

et al. 2006

Molecular and Cellular Biology

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“…Other members of the hnRNP family were reported to be related to HBV or HCC. For example, hnRNP K (64), hnRNP H/HЈ (65), and Hcc-1 (with sequence matches to hnRNP but localized to chromosome 7q22.1, which is different than hnRNP C1/C2) (66). But there has been no report about the up-regulation of hnRNP C1/C2 in HCC.…”

Section: Members Of Heat Shock Protein 70 and 90 Familiesmentioning

confidence: 99%

Proteome Analysis of Hepatocellular Carcinoma by Two-dimensional Difference Gel Electrophoresis

Sun

Xing

Sun

et al. 2007

Molecular & Cellular Proteomics

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172

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Hepatocellular carcinoma (HCC) is a highly malignant tumor, and chronic infection with hepatitis B virus is one of its major risk factors. To identify the proteins involved in HCC carcinogenesis, we used two-dimensional fluorescence DIGE to study the differentially expressed proteins in tumor and adjacent nontumor tissue samples. Samples from 12 hepatitis B virus-associated HCC patients were analyzed. A total of 61 spots were significantly up-regulated (ratio > 2, p < 0.01) in tumor samples, whereas 158 spots were down-regulated (ratio < ؊2, p < 0.01). Seventyone gene products were identified among these spots. Members of the heat shock protein 70 and 90 families were simultaneously up-regulated, whereas metabolismassociated proteins were decreased in HCC samples. The down-regulation of mitochondrial and peroxisomal proteins in these results suggested loss of special organelle functions during HCC carcinogenesis. Four metabolic enzymes involved in the methylation cycle in the liver were down-regulated in HCC tissues, indicating S-adenosylmethionine deficiency in HCC. Two gene products, glyceraldehyde-3-phosphate dehydrogenase and formimidoyltransferase-cyclodeaminase, were identified from inversely altered spots, suggesting that different isoforms or post-translational modifications of these two proteins might play different roles in HCC. For the first time, the overexpression of Hcp70/Hsp90-organizing protein and heterogeneous nuclear ribonucleoproteins C1/C2 in HCC tissues was confirmed by Western blot and then by immunohistochemistry staining in 70 HCC samples, suggesting their potential as protein tumor markers. In summary, we profiled proteome alterations in HCC tissues, and these results may provide useful insights for understanding the mechanism involved in the process of Proteomics analysis is currently considered to be a powerful tool for global evaluation of protein expression, and proteomics has been widely applied in analysis of diseases, especially in fields of cancer research. Quantitative protein expression profiling is a crucial part of proteomics, and such profiling requires methods that are able to efficiently provide accurate and reproducible differential expression values for proteins in two or more biological samples. Two-dimensional electrophoresis (2DE) 1 was a technique that was widely used for proteomics research. However, intergel variation and excessive time/labor costs have been common problems with standard 2DE. Two-dimensional (2D) DIGE might therefore be considered as one of the most significant advances in quantitative proteomics. Using the 2D DIGE approach, different samples prelabeled with mass-and charge-matched fluorescent cyanine dyes are co-separated in the same 2D gel, and an internal standard is used in every gel that has negated the problem of intergel variation (1). Moreover with the great sensitivity and dynamic range that is afforded by these dyes, 2D DIGE can give greater accuracy of quantitation than silver staining (2). It has been reported that the correlation betw...

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“…Hcc-1 cDNA level increased in pancreatic adenocarcinoma. The level also increased in a well-differentiated hepatocellular carcinoma but decreased as carcinoma progressed to a poorly differentiated stage [9].…”

Section: Introductionmentioning

confidence: 90%

“…CIP29 appears to be a new cytokineregulated protein involved in normal and cancer cell proliferation. The Hcc-1 and CIP29 genes were identified to encode the same protein [9,11].…”

Section: Introductionmentioning

confidence: 99%

Isolation and Characterization of mas1⁺of Schizosaccharomyces pombe, a Homologue of Human CIP29/Hcc-1 Involved in the Regulation of Cell Division

Young¹,

Shin²,

Ha³

et al. 2011

Journal of Life Science

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The regulation of gene expression plays an important role in cell cycle controls. In this study, a novel gene, the mas1 + (mitosis associated protein) gene, a homolog of human CIP29/Hcc1, was isolated and characterized from fission yeast Schizosaccharomyces pombe (S. pombe) using a gene-specific polymerase chain reaction. The isolated gene contained a complete open reading frame capable of encoding 245 amino acid residues with a typical promoter, as judged by nucleotide sequence analysis. It was also found that a PCB (pombe cell cycle box) is located in the promoter region, which controls M-G1 specific transcription in S. pombe. The quantitative analysis of the mas1 + transcript against adh1 + showed that the pattern of expression is similar to that of the septation index. Cytokinesis of mas1 null mutant was greatly delayed at 25℃ and 36℃, and a large number of multi-septate cells were produced. The mas1 null mutant had 2C, 4C and 6C DNA contents, as determined by FACS analysis. In addition, the number of multi-septate cells significantly increased. When cells were cultured in nitrogen starvation medium to increase proliferation, the abnormal phenotypes of mas1 null mutant dramatically increased. These phenotypes could be rescued by an overexpression of the mas1 + gene. The mas1 protein localized in the nuclei of S. pombe and human HeLa cells, as evidenced by Mas1-EGFP signals. The abnormal growth pattern and the morphology of mas1 null mutant were complemented by a plasmid carrying human CIP29/Hcc-1cDNA. In addition, CIP29 /Hcc-1 transcript level increased in active cell proliferation stages in the developing mouse embryos. These results indicate that the mas1 + ishomologous to the human CIP29/Hcc1 gene and is involved in cytokinesis and cell shape control.

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An integrated approach in the discovery and characterization of a novel nuclear protein over‐expressed in liver and pancreatic tumors

Cited by 37 publications

References 37 publications

Tho1, a Novel hnRNP, and Sub2 Provide Alternative Pathways for mRNP Biogenesis in Yeast THO Mutants

Tho1, a Novel hnRNP, and Sub2 Provide Alternative Pathways for mRNP Biogenesis in Yeast THO Mutants

Proteome Analysis of Hepatocellular Carcinoma by Two-dimensional Difference Gel Electrophoresis

Isolation and Characterization of mas1⁺of Schizosaccharomyces pombe, a Homologue of Human CIP29/Hcc-1 Involved in the Regulation of Cell Division

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An integrated approach in the discovery and characterization of a novel nuclear protein over‐expressed in liver and pancreatic tumors

Cited by 37 publications

References 37 publications

Tho1, a Novel hnRNP, and Sub2 Provide Alternative Pathways for mRNP Biogenesis in Yeast THO Mutants

Tho1, a Novel hnRNP, and Sub2 Provide Alternative Pathways for mRNP Biogenesis in Yeast THO Mutants

Proteome Analysis of Hepatocellular Carcinoma by Two-dimensional Difference Gel Electrophoresis

Isolation and Characterization of mas1+of Schizosaccharomyces pombe, a Homologue of Human CIP29/Hcc-1 Involved in the Regulation of Cell Division

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Isolation and Characterization of mas1⁺of Schizosaccharomyces pombe, a Homologue of Human CIP29/Hcc-1 Involved in the Regulation of Cell Division