1
|
Roesmann F, Sertznig H, Klaassen K, Wilhelm A, Heininger D, Heß S, Elsner C, Marschalek R, Santiago ML, Esser S, Sutter K, Dittmer U, Widera M. The interferon-regulated host factor hnRNPA0 modulates HIV-1 production by interference with LTR activity, mRNA trafficking, and programmed ribosomal frameshifting. J Virol 2024:e0053424. [PMID: 38899932 DOI: 10.1128/jvi.00534-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Accepted: 05/29/2024] [Indexed: 06/21/2024] Open
Abstract
The interplay between host factors and viral components impacts viral replication efficiency profoundly. Members of the cellular heterogeneous nuclear ribonucleoprotein family (hnRNPs) have been extensively studied as HIV-1 host dependency factors, but whether they play a role in innate immunity is currently unknown. This study aimed to identify hnRNPA0 as a type I interferon (IFN)-repressed host factor in HIV-1-infected cells. Knockdown of hnRNPA0, a situation that mirrors conditions under IFN stimulation, increased LTR activity, export of unspliced HIV-1 mRNA, viral particle production, and thus, increased infectivity. Conversely, hnRNPA0 overexpression primarily reduced plasmid-driven and integrated HIV-1 long terminal repeat (LTR) activity, significantly decreasing total viral mRNA and protein levels. In addition, high levels of hnRNPA0 significantly reduced the HIV-1 programmed ribosomal frameshifting efficiency, resulting in a shift in the HIV-1 p55/p15 ratio. The HIV-1 alternative splice site usage remained largely unaffected by altered hnRNPA0 levels suggesting that the synergistic inhibition of the LTR activity and viral mRNA transcription, as well as impaired ribosomal frameshifting efficiency, are critical factors for efficient HIV-1 replication regulated by hnRNPA0. The pleiotropic dose-dependent effects under high or low hnRNPA0 levels were further confirmed in HIV-1-infected Jurkat cells. Finally, our study revealed that hnRNPA0 levels in PBMCs were lower in therapy-naive HIV-1-infected individuals compared to healthy controls. Our findings highlight a significant role for hnRNPA0 in HIV-1 replication and suggest that its IFN-I-regulated expression levels are critical for viral fitness allowing replication in an antiviral environment.IMPORTANCERNA-binding proteins, in particular, heterogeneous nuclear ribonucleoproteins (hnRNPs), have been extensively studied. Some act as host dependency factors for HIV-1 since they are involved in multiple cellular gene expression processes. Our study revealed hnRNPA0 as an IFN-regulated host factor, that is differently expressed after IFN-I treatment in HIV-1 target cells and lower expressed in therapy-naïve HIV-1-infected individuals. Our findings demonstrate the significant pleiotropic role of hnRNPA0 in viral replication: In high concentrations, hnRNPA0 limits viral replication by negatively regulating Tat-LTR transcription, retaining unspliced mRNA in the nucleus, and significantly impairing programmed ribosomal frameshifting. Low hnRNPA0 levels as observed in IFN-treated THP-1 cells, particularly facilitate HIV LTR activity and unspliced mRNA export, suggesting a role in innate immunity in favor of HIV replication. Understanding the mode of action between hnRNPA0 and HIV-1 gene expression might help to identify novel therapeutically strategies against HIV-1 and other viruses.
Collapse
Affiliation(s)
- Fabian Roesmann
- Goethe University Frankfurt, University Hospital, Institute for Medical Virology, Frankfurt, Germany
| | - Helene Sertznig
- Institute for Virology, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Katleen Klaassen
- Goethe University Frankfurt, University Hospital, Institute for Medical Virology, Frankfurt, Germany
| | - Alexander Wilhelm
- Goethe University Frankfurt, University Hospital, Institute for Medical Virology, Frankfurt, Germany
| | - Delia Heininger
- Goethe University Frankfurt, University Hospital, Institute for Medical Virology, Frankfurt, Germany
| | - Stefanie Heß
- Goethe University Frankfurt, University Hospital, Institute for Medical Virology, Frankfurt, Germany
| | - Carina Elsner
- Institute for Virology, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Rolf Marschalek
- Institute of Pharmaceutical Biology, Goethe-University, Frankfurt am Main, Hessen, Germany
| | - Mario L Santiago
- Department of Medicine, University of Colorado Denver, Aurora, Colorado, USA
| | - Stefan Esser
- Institute for the Research on HIV and AIDS-associated Diseases University Hospital Essen, University Duisburg-Essen, Essen, Germany
- Department of Dermatology, HPSTD Outpatient Clinic, University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Kathrin Sutter
- Institute for Virology, University Hospital Essen, University Duisburg-Essen, Essen, Germany
- Institute for the Research on HIV and AIDS-associated Diseases University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Ulf Dittmer
- Institute for Virology, University Hospital Essen, University Duisburg-Essen, Essen, Germany
- Institute for the Research on HIV and AIDS-associated Diseases University Hospital Essen, University Duisburg-Essen, Essen, Germany
| | - Marek Widera
- Goethe University Frankfurt, University Hospital, Institute for Medical Virology, Frankfurt, Germany
| |
Collapse
|
2
|
Mar D, Babenko IM, Zhang R, Noble WS, Denisenko O, Vaisar T, Bomsztyk K. MultiomicsTracks96: A high throughput PIXUL-Matrix-based toolbox to profile frozen and FFPE tissues multiomes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.16.533031. [PMID: 36993219 PMCID: PMC10055122 DOI: 10.1101/2023.03.16.533031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
Background The multiome is an integrated assembly of distinct classes of molecules and molecular properties, or "omes," measured in the same biospecimen. Freezing and formalin-fixed paraffin-embedding (FFPE) are two common ways to store tissues, and these practices have generated vast biospecimen repositories. However, these biospecimens have been underutilized for multi-omic analysis due to the low throughput of current analytical technologies that impede large-scale studies. Methods Tissue sampling, preparation, and downstream analysis were integrated into a 96-well format multi-omics workflow, MultiomicsTracks96. Frozen mouse organs were sampled using the CryoGrid system, and matched FFPE samples were processed using a microtome. The 96-well format sonicator, PIXUL, was adapted to extract DNA, RNA, chromatin, and protein from tissues. The 96-well format analytical platform, Matrix, was used for chromatin immunoprecipitation (ChIP), methylated DNA immunoprecipitation (MeDIP), methylated RNA immunoprecipitation (MeRIP), and RNA reverse transcription (RT) assays followed by qPCR and sequencing. LC-MS/MS was used for protein analysis. The Segway genome segmentation algorithm was used to identify functional genomic regions, and linear regressors based on the multi-omics data were trained to predict protein expression. Results MultiomicsTracks96 was used to generate 8-dimensional datasets including RNA-seq measurements of mRNA expression; MeRIP-seq measurements of m6A and m5C; ChIP-seq measurements of H3K27Ac, H3K4m3, and Pol II; MeDIP-seq measurements of 5mC; and LC-MS/MS measurements of proteins. We observed high correlation between data from matched frozen and FFPE organs. The Segway genome segmentation algorithm applied to epigenomic profiles (ChIP-seq: H3K27Ac, H3K4m3, Pol II; MeDIP-seq: 5mC) was able to recapitulate and predict organ-specific super-enhancers in both FFPE and frozen samples. Linear regression analysis showed that proteomic expression profiles can be more accurately predicted by the full suite of multi-omics data, compared to using epigenomic, transcriptomic, or epitranscriptomic measurements individually. Conclusions The MultiomicsTracks96 workflow is well suited for high dimensional multi-omics studies - for instance, multiorgan animal models of disease, drug toxicities, environmental exposure, and aging as well as large-scale clinical investigations involving the use of biospecimens from existing tissue repositories.
Collapse
|
3
|
Riccioni V, Trionfetti F, Montaldo C, Garbo S, Marocco F, Battistelli C, Marchetti A, Strippoli R, Amicone L, Cicchini C, Tripodi M. SYNCRIP Modulates the Epithelial-Mesenchymal Transition in Hepatocytes and HCC Cells. Int J Mol Sci 2022; 23:ijms23020913. [PMID: 35055098 PMCID: PMC8780347 DOI: 10.3390/ijms23020913] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/10/2022] [Accepted: 01/11/2022] [Indexed: 02/04/2023] Open
Abstract
Heterogeneous nuclear ribonucleoproteins (hnRNPs) control gene expression by acting at multiple levels and are often deregulated in epithelial tumors; however, their roles in the fine regulation of cellular reprogramming, specifically in epithelial–mesenchymal transition (EMT), remain largely unknown. Here, we focused on the hnRNP-Q (also known as SYNCRIP), showing by molecular analysis that in hepatocytes it acts as a “mesenchymal” gene, being induced by TGFβ and modulating the EMT. SYNCRIP silencing limits the induction of the mesenchymal program and maintains the epithelial phenotype. Notably, in HCC invasive cells, SYNCRIP knockdown induces a mesenchymal–epithelial transition (MET), negatively regulating their mesenchymal phenotype and significantly impairing their migratory capacity. In exploring possible molecular mechanisms underlying these observations, we identified a set of miRNAs (i.e., miR-181-a1-3p, miR-181-b1-3p, miR-122-5p, miR-200a-5p, and miR-let7g-5p), previously shown to exert pro- or anti-EMT activities, significantly impacted by SYNCRIP interference during EMT/MET dynamics and gathered insights, suggesting the possible involvement of this RNA binding protein in their transcriptional regulation.
Collapse
Affiliation(s)
- Veronica Riccioni
- Department of Molecular Medicine, Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, 00161 Rome, Italy; (V.R.); (F.T.); (S.G.); (F.M.); (C.B.); (A.M.); (R.S.); (L.A.)
| | - Flavia Trionfetti
- Department of Molecular Medicine, Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, 00161 Rome, Italy; (V.R.); (F.T.); (S.G.); (F.M.); (C.B.); (A.M.); (R.S.); (L.A.)
- National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy;
| | - Claudia Montaldo
- National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy;
| | - Sabrina Garbo
- Department of Molecular Medicine, Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, 00161 Rome, Italy; (V.R.); (F.T.); (S.G.); (F.M.); (C.B.); (A.M.); (R.S.); (L.A.)
| | - Francesco Marocco
- Department of Molecular Medicine, Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, 00161 Rome, Italy; (V.R.); (F.T.); (S.G.); (F.M.); (C.B.); (A.M.); (R.S.); (L.A.)
| | - Cecilia Battistelli
- Department of Molecular Medicine, Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, 00161 Rome, Italy; (V.R.); (F.T.); (S.G.); (F.M.); (C.B.); (A.M.); (R.S.); (L.A.)
| | - Alessandra Marchetti
- Department of Molecular Medicine, Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, 00161 Rome, Italy; (V.R.); (F.T.); (S.G.); (F.M.); (C.B.); (A.M.); (R.S.); (L.A.)
| | - Raffaele Strippoli
- Department of Molecular Medicine, Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, 00161 Rome, Italy; (V.R.); (F.T.); (S.G.); (F.M.); (C.B.); (A.M.); (R.S.); (L.A.)
- National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy;
| | - Laura Amicone
- Department of Molecular Medicine, Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, 00161 Rome, Italy; (V.R.); (F.T.); (S.G.); (F.M.); (C.B.); (A.M.); (R.S.); (L.A.)
| | - Carla Cicchini
- Department of Molecular Medicine, Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, 00161 Rome, Italy; (V.R.); (F.T.); (S.G.); (F.M.); (C.B.); (A.M.); (R.S.); (L.A.)
- Correspondence: (C.C.); (M.T.)
| | - Marco Tripodi
- Department of Molecular Medicine, Istituto Pasteur Italia-Fondazione Cenci Bolognetti, Sapienza University of Rome, 00161 Rome, Italy; (V.R.); (F.T.); (S.G.); (F.M.); (C.B.); (A.M.); (R.S.); (L.A.)
- National Institute for Infectious Diseases L. Spallanzani, IRCCS, 00149 Rome, Italy;
- Correspondence: (C.C.); (M.T.)
| |
Collapse
|
4
|
Peng C, Tan Y, Yang P, Jin K, Zhang C, Peng W, Wang L, Zhou J, Chen R, Wang T, Jin C, Ji J, Feng Y, Tang J, Sun Y. Circ-GALNT16 restrains colorectal cancer progression by enhancing the SUMOylation of hnRNPK. J Exp Clin Cancer Res 2021; 40:272. [PMID: 34452628 PMCID: PMC8400830 DOI: 10.1186/s13046-021-02074-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Accepted: 08/14/2021] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND Recent studies have investigated the role of circular RNAs (circRNAs) as significant regulatory factors in multiple cancer progression. Nevertheless, the biological functions of circRNAs and the underlying mechanisms by which they regulate colorectal cancer (CRC) progression remain unclear. METHODS A novel circRNA (circ-GALNT16) was identified by microarray and qRT-PCR. A series of in vitro and in vivo phenotype experiments were performed to investigate the role of circ-GALNT16 in CRC. The FISH, RNA pulldown assay, RIP assay, RNA sequencing, coimmunoprecipitation, and ChIP were performed to investigate the molecular mechanisms of circ-GALNT16 in CRC progression. RESULTS Circ-GALNT16 was downregulated in CRC and was negatively correlated with poor prognosis. Circ-GALNT16 suppressed the proliferation and metastatic ability of CRC cells in vitro and in vivo. Mechanistically, circ-GALNT16 could bind to the KH3 domain of heterogeneous nuclear ribonucleoprotein K (hnRNPK), which promoted the SUMOylation of hnRNPK. Additionally, circ-GALNT16 could enhance the formation of the hnRNPK-p53 complex by facilitating the SUMOylation of hnRNPK. RNA sequencing assay identified serpin family E member 1 as the target gene of circ-GALNT16 at the transcriptional level. Rescue assays revealed that circ-GALNT16 regulated the expression of Serpine1 by inhibiting the deSUMOylation of hnRNPK mediated by SUMO-specific peptidase 2 and then regulating the sequence-specific DNA binding ability of the hnRNPK-p53 transcriptional complex. CONCLUSIONS Circ-GALNT16 suppressed CRC progression by inhibiting Serpine1 expression through regulating the sequence-specific DNA binding ability of the SENP2-mediated hnRNPK-p53 transcriptional complex and might function as a biomarker and therapeutic target for CRC.
Collapse
Affiliation(s)
- Chaofan Peng
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China
- Nanjing Medical University, Nanjing, China
| | - Yuqian Tan
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China
- Nanjing Medical University, Nanjing, China
| | - Peng Yang
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China
- Nanjing Medical University, Nanjing, China
| | - Kangpeng Jin
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China
- Nanjing Medical University, Nanjing, China
| | - Chuan Zhang
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China
- Nanjing Medical University, Nanjing, China
| | - Wen Peng
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China
- Nanjing Medical University, Nanjing, China
| | - Lu Wang
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China
- Nanjing Medical University, Nanjing, China
| | - Jiahui Zhou
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China
- Nanjing Medical University, Nanjing, China
| | - Ranran Chen
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China
- Nanjing Medical University, Nanjing, China
| | - Tuo Wang
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China
- Nanjing Medical University, Nanjing, China
| | - Chi Jin
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China
- Nanjing Medical University, Nanjing, China
| | - Jiangzhou Ji
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China
- Nanjing Medical University, Nanjing, China
| | - Yifei Feng
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China
- Nanjing Medical University, Nanjing, China
| | - Junwei Tang
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China.
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China.
- Nanjing Medical University, Nanjing, China.
| | - Yueming Sun
- Department of General Surgery, The First Affiliated Hospital of Nanjing Medical University, Jiangsu, 210029, Nanjing, People's Republic of China.
- The First School of Clinical Medicine, Nanjing Medical University, Nanjing, China.
- Nanjing Medical University, Nanjing, China.
| |
Collapse
|
5
|
Swiatkowska A, Dutkiewicz M, Machtel P, Janecki DM, Kabacinska M, Żydowicz-Machtel P, Ciesiołka J. Regulation of the p53 expression profile by hnRNP K under stress conditions. RNA Biol 2020; 17:1402-1415. [PMID: 32449427 DOI: 10.1080/15476286.2020.1771944] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The p53 protein is one of the transcription factors responsible for cell cycle regulation and prevention of cancer development. Its expression is regulated at the transcriptional, translational and post-translational levels. Recent years of research have shown that the 5' terminus of p53 mRNA plays an important role in this regulation. This region seems to be a docking platform for proteins involved in p53 expression, particularly under stress conditions. Here, we applied RNA-centric affinity chromatography to search for proteins that bind to the 5' terminus of p53 mRNA and thus may be able to regulate the p53 expression profile. We found heterogeneous nuclear ribonucleoprotein K, hnRNP K, to be one of the top candidates. Binding of hnRNP K to the 5'-terminal region of p53 mRNA was confirmed in vitro. We demonstrated that changes in the hnRNP K level in the cell strongly affected the p53 expression profile under various stress conditions. Downregulation or overexpression of hnRNP K caused a decrease or an increase in the p53 mRNA amount, respectively, pointing to the transcriptional mode of expression regulation. However, when hnRNP K was overexpressed under endoplasmic reticulum stress and the p53 amount has elevated no changes in the p53 mRNA level were detected suggesting translational regulation of p53 expression. Our findings have shown that hnRNP K is not only a mutual partner of p53 in the transcriptional activation of target genes under stress conditions but it also acts as a regulator of p53 expression at the transcriptional and potentially translational levels.
Collapse
Affiliation(s)
- Agata Swiatkowska
- Polish Academy of Sciences, Institute of Bioorganic Chemistry , Poznan, Poland
| | - Mariola Dutkiewicz
- Polish Academy of Sciences, Institute of Bioorganic Chemistry , Poznan, Poland
| | - Piotr Machtel
- Polish Academy of Sciences, Institute of Bioorganic Chemistry , Poznan, Poland
| | - Damian M Janecki
- Polish Academy of Sciences, Institute of Bioorganic Chemistry , Poznan, Poland
| | - Martyna Kabacinska
- Polish Academy of Sciences, Institute of Bioorganic Chemistry , Poznan, Poland
| | | | - Jerzy Ciesiołka
- Polish Academy of Sciences, Institute of Bioorganic Chemistry , Poznan, Poland
| |
Collapse
|
6
|
Wang Z, Qiu H, He J, Liu L, Xue W, Fox A, Tickner J, Xu J. The emerging roles of hnRNPK. J Cell Physiol 2019; 235:1995-2008. [PMID: 31538344 DOI: 10.1002/jcp.29186] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 08/23/2019] [Indexed: 12/15/2022]
Abstract
Heterogeneous nuclear ribonucleoprotein K (hnRNPK) is an DNA/RNA-binding protein and regulates a wide range of biological processes and disease pathogenesis. It contains 3 K-homologous (KH) domains, which are conserved in other RNA-binding proteins, mediate nucleic acid binding activity, and function as an enhancer or repressor of gene transcription. Phosphorylation of the protein alters its regulatory function, which also enables the protein to serve as a docking platform for the signal transduction proteins. In terms of the function of hnRNPK, it is central to many cellular events, including long noncoding RNA (lncRNA) regulation, cancer development and bone homoeostasis. Many studies have identified hnRNPK as an oncogene, where it is overexpressed in cancer tissues compared with the nonneoplastic tissues and its expression level is related to the prognosis of different types of host malignancies. However, hnRNPK has also been identified as a tumour suppressor, as it is important for the activation of the p53/p21 pathway. Recently, the protein is also found to be exclusively related to the regulation of paraspeckles and lncRNAs such as Neat1, Lncenc1 and Xist. Interestingly, hnRNPK has been found to associate with the Kabuki-like syndrome and Au-Kline syndrome with prominent skeletal abnormalities. In vitro study revealed that the hnRNPK protein is essential for the formation of osteoclast, in line with its importance in the skeletal system.
Collapse
Affiliation(s)
- Ziyi Wang
- School of Biomedical Sciences, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Heng Qiu
- School of Biomedical Sciences, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Jianbo He
- School of Biomedical Sciences, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, Western Australia, Australia.,Guangzhou University of Chinese Medicine, Guangzhou, Guangdong, China
| | - Langxia Liu
- Key laboratory of functional protein research of Guangdong higher education institutes, Institute of life and health engineering, Jinan University, Guangzhou, China
| | - Wei Xue
- Department of Biomedical Engineering, Jinan University, Guangzhou, China
| | - Archa Fox
- School of Human Sciences and Molecular Sciences, The University of Western Australia and Harry Perkins Institute of Medical Research, Centre for Medical Research, The University of Western Australia, Perth, Western Australia, Australia
| | - Jennifer Tickner
- School of Biomedical Sciences, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Jiake Xu
- School of Biomedical Sciences, Faculty of Health and Medical Sciences, The University of Western Australia, Perth, Western Australia, Australia
| |
Collapse
|
7
|
Nazarov IB, Bakhmet EI, Tomilin AN. KH-Domain Poly(C)-Binding Proteins as Versatile Regulators of Multiple Biological Processes. BIOCHEMISTRY (MOSCOW) 2019; 84:205-219. [PMID: 31221059 DOI: 10.1134/s0006297919030039] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Five known members of the family of KH-domain poly(C)-binding proteins (Pcbp1-4, hnRNP-K) have an unusually broad spectrum of cellular functions that include regulation of gene transcription, regulation of pre-mRNA processing, splicing, mRNA stability, translational silencing and enhancement, the control of iron turnover, and many others. Mechanistically, these proteins act via nucleic acid binding and protein-protein interactions. Through performing these multiple tasks, the KH-domain poly(C)-binding family members are involved in a wide variety of biological processes such as embryonic development, cell differentiation, and cancer. Deregulation of KH-domain protein expression is frequently associated with severe developmental defects and neoplasia. This review summarizes progress in studies of the KH-domain proteins made over past two decades. The review also reports our recent finding implying an involvement of the KH-factor Pcbp1 into control of transition from naïve to primed pluripotency cell state.
Collapse
Affiliation(s)
- I B Nazarov
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russia.
| | - E I Bakhmet
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russia
| | - A N Tomilin
- Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russia
| |
Collapse
|
8
|
Bakhmet EI, Nazarov IB, Gazizova AR, Vorobyeva NE, Kuzmin AA, Gordeev MN, Sinenko SA, Aksenov ND, Artamonova TO, Khodorkovskii MA, Alenina N, Onichtchouk D, Wu G, Schöler HR, Tomilin AN. hnRNP-K Targets Open Chromatin in Mouse Embryonic Stem Cells in Concert with Multiple Regulators. Stem Cells 2019; 37:1018-1029. [PMID: 31021473 DOI: 10.1002/stem.3025] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2018] [Revised: 04/12/2019] [Accepted: 04/13/2019] [Indexed: 01/02/2023]
Abstract
The transcription factor Oct4 plays a key regulatory role in the induction and maintenance of cellular pluripotency. In this article, we show that ubiquitous and multifunctional poly(C) DNA/RNA-binding protein hnRNP-K occupies Oct4 (Pou5f1) enhancers in embryonic stem cells (ESCs) but is dispensable for the initiation, maintenance, and downregulation of Oct4 gene expression. Nevertheless, hnRNP-K has an essential cell-autonomous function in ESCs to maintain their proliferation and viability. To better understand mechanisms of hnRNP-K action in ESCs, we have performed ChIP-seq analysis of genome-wide binding of hnRNP-K and identified several thousands of hnRNP-K target sites that are frequently co-occupied by pluripotency-related and common factors (Oct4, TATA-box binding protein, Sox2, Nanog, Otx2, etc.), as well as active histone marks. Furthermore, hnRNP-K localizes exclusively within open chromatin, implying its role in the onset and/or maintenance of this chromatin state. Stem Cells 2019;37:1018-1029.
Collapse
Affiliation(s)
- Evgeny I Bakhmet
- Laboratory of the Molecular Biology of Stem Cells, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Igor B Nazarov
- Laboratory of the Molecular Biology of Stem Cells, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Adel R Gazizova
- Laboratory of the Molecular Biology of Stem Cells, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Nadezhda E Vorobyeva
- Group of transcriptional complexes dynamics, Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia
| | - Andrey A Kuzmin
- Laboratory of the Molecular Biology of Stem Cells, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Mikhail N Gordeev
- Laboratory of the Molecular Biology of Stem Cells, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Sergey A Sinenko
- Laboratory of the Molecular Biology of Stem Cells, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Nikolai D Aksenov
- Laboratory of the Molecular Biology of Stem Cells, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia
| | - Tatyana O Artamonova
- Institute of Nanobiotechnologies, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
| | - Mikhail A Khodorkovskii
- Institute of Nanobiotechnologies, Peter the Great St. Petersburg Polytechnic University, St. Petersburg, Russia
| | - Natalia Alenina
- Molecular Biology of Peptide Hormones, Max-Delbrück Center for Molecular Medicine, Berlin-Buch, Germany
| | - Daria Onichtchouk
- Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
| | - Guangming Wu
- Department of Cell and Developmental Biology, Max-Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Hans R Schöler
- Department of Cell and Developmental Biology, Max-Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Alexey N Tomilin
- Laboratory of the Molecular Biology of Stem Cells, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, Russia.,Laboratory of Cellular and Molecular Biology, Institute of Translational Biomedicine, St. Petersburg State University, St. Petersburg, Russia
| |
Collapse
|
9
|
Zhu Y, Gong Y, Li A, Chen M, Kang D, Liu J, Yuan Y. Differential Proteomic Analysis Reveals Protein Networks and Pathways that May Contribute to Helicobacter pylori FKBP-Type PPIase-Associated Gastric Diseases. Proteomics Clin Appl 2017; 12:e1700127. [PMID: 29148176 DOI: 10.1002/prca.201700127] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 10/21/2017] [Indexed: 12/18/2022]
Abstract
PURPOSE Though Helicobacter pylori (H. pylori) has been classified as class I carcinogen, key virulence factor generated by H. pylori that causes gastric cancer remains to be fully determined. Recently, we identified a gastric cancer-associated H. pylori gene, peptidylprolyl isomerase-FK506 binding protein (PPIase-FKBP), and showed that PPIase-FKBP was capable of inducing oncogenic transformation of gastric epithelial cells. But its mechanism was unclear. EXPERIMENTAL DESIGN We carried out a comparative proteomic analysis of human gastric epithelial cells that either express PPIase-FKBP or green fluorescent protein using 2-DE and then MALDI-TOF-MS/MS. RESULTS Our results identified 28 differentially expressed proteins induced by PPIase-FKBP. These proteins participate in some cellular biological processes, such as cell proliferation, cell apoptosis and DNA replication, mRNA splicing, and protein biosynthesis. Ingenuity Pathway Analysis categorized the 28 proteins into two molecular interaction networks, involved primarily in cancer and gastrointestinal diseases. CONCLUSIONS AND CLINICAL RELEVANCE Our results provided insight on the protein interaction networks and signaling pathways that may contribute to PPIase-FKBP-associated gastric diseases and may lead to a better understanding of the mechanisms indicating the oncogenic effects of H. pylori PPIase-FKBP.
Collapse
Affiliation(s)
- Yanmei Zhu
- Department of Pathology, Cancer Hospital of China Medical University, Liaoning Cancer Hospital and Institute, Shenyang, China.,Tumor Etiology and Screening Department of Cancer Institute and General Surgery, The First Affiliated Hospital of China Medical University, Key Laboratory of Cancer Etiology and Prevention, Liaoning Provincial Education Department, China Medical University, Shenyang, China.,West Virginia University Cancer Institute, West Virginia University, Morgantown, WV, USA
| | - Yuehua Gong
- Tumor Etiology and Screening Department of Cancer Institute and General Surgery, The First Affiliated Hospital of China Medical University, Key Laboratory of Cancer Etiology and Prevention, Liaoning Provincial Education Department, China Medical University, Shenyang, China
| | - Aodi Li
- Tumor Etiology and Screening Department of Cancer Institute and General Surgery, The First Affiliated Hospital of China Medical University, Key Laboratory of Cancer Etiology and Prevention, Liaoning Provincial Education Department, China Medical University, Shenyang, China
| | - Moye Chen
- Tumor Etiology and Screening Department of Cancer Institute and General Surgery, The First Affiliated Hospital of China Medical University, Key Laboratory of Cancer Etiology and Prevention, Liaoning Provincial Education Department, China Medical University, Shenyang, China
| | - Dan Kang
- Tumor Etiology and Screening Department of Cancer Institute and General Surgery, The First Affiliated Hospital of China Medical University, Key Laboratory of Cancer Etiology and Prevention, Liaoning Provincial Education Department, China Medical University, Shenyang, China
| | - Jun Liu
- West Virginia University Cancer Institute, West Virginia University, Morgantown, WV, USA
| | - Yuan Yuan
- Tumor Etiology and Screening Department of Cancer Institute and General Surgery, The First Affiliated Hospital of China Medical University, Key Laboratory of Cancer Etiology and Prevention, Liaoning Provincial Education Department, China Medical University, Shenyang, China
| |
Collapse
|
10
|
Lu J, Gao FH. Role and molecular mechanism of heterogeneous nuclear ribonucleoprotein K in tumor development and progression. Biomed Rep 2016; 4:657-663. [PMID: 27284403 DOI: 10.3892/br.2016.642] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 03/01/2016] [Indexed: 12/20/2022] Open
Abstract
Heterogeneous nuclear ribonucleoprotein K (hnRNP K) is a member of the hnRNP family, which exists in the nucleus and the cytoplasm simultaneously. It is a multifunctional protein that can participate in a variety of regulatory progressions of gene expression and signal transduction, such as chromatin remodeling, transcription, RNA alternative splicing and translation. hnRNP K not only directly binds to the kinases, but also recruits the associated factors regarding transcription, splicing and translation to control gene expression, and therefore, it serves as a docking platform for integrating transduction pathways to nucleic acid-directed processes. Numerous studies also show that abnormal expression of hnRNP K is closely associated with the tumor formation. This protein is overexpressed in numerous types of cancer and its aberrant cytoplasmic localization is also associated with a worse prognosis for patients. These results consistently indicate that hnRNP K has a key role in cancer progression. To understand the hnRNP K pathophysiological process in tumor disease, the previous research results regarding the association between hnRNP K and tumors were reviewed.
Collapse
Affiliation(s)
- Jing Lu
- Institute of Oncology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, P.R. China
| | - Feng-Hou Gao
- Institute of Oncology, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200011, P.R. China
| |
Collapse
|
11
|
Zhang P, Wang N, Lin X, Jin L, Xu H, Li R, Huang H. Expression and localization of heterogeneous nuclear ribonucleoprotein K in mouse ovaries and preimplantation embryos. Biochem Biophys Res Commun 2016; 471:260-5. [PMID: 26850853 DOI: 10.1016/j.bbrc.2016.02.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 02/01/2016] [Indexed: 01/08/2023]
Abstract
Heterogeneous nuclear ribonucleoprotein K (hnRNP K), an evolutionarily conserved protein, is involved in several important cellular processes that are relevant to cell proliferation, differentiation, apoptosis, and cancer development. However, details of hnRNP K expression during mammalian oogenesis and preimplantation embryo development are lacking. The present study investigates the expression and cellular localization of K protein in the mouse ovaries and preimplantation embryos using immunostaining. We demonstrate, for the first time, that hnRNP K is abundantly expressed in the nuclei of mouse oocytes in primordial, primary and secondary follicles. In germ vesicle (GV)-stage oocytes, hnRNP K accumulates in the germinal vesicle in a spot distribution manner. After germinal vesicle breakdown, speckled hnRNP K is diffusely distributed in the cytoplasm. However, after fertilization, the K protein relocates into the female and male pronucleus and persists in the blastomere nuclei. Localization of K protein in the human ovary and ovarian granulosa cell tumor (GCT) was also investigated. Overall, this study provides important morphological evidence to better understand the possible roles of hnRNP K in mammalian oogenesis and early embryo development.
Collapse
Affiliation(s)
- Ping Zhang
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Ningling Wang
- Department of Assisted Reproduction, Shanghai Ninth People's Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Xianhua Lin
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Li Jin
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Hong Xu
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
| | - Rong Li
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Hefeng Huang
- The International Peace Maternity and Child Health Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China.
| |
Collapse
|
12
|
Barboro P, Ferrari N, Balbi C. Emerging roles of heterogeneous nuclear ribonucleoprotein K (hnRNP K) in cancer progression. Cancer Lett 2014; 352:152-9. [DOI: 10.1016/j.canlet.2014.06.019] [Citation(s) in RCA: 75] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Revised: 06/26/2014] [Accepted: 06/29/2014] [Indexed: 12/18/2022]
|
13
|
Ryu J, Kaul Z, Yoon AR, Liu Y, Yaguchi T, Na Y, Ahn HM, Gao R, Choi IK, Yun CO, Kaul SC, Wadhwa R. Identification and functional characterization of nuclear mortalin in human carcinogenesis. J Biol Chem 2014; 289:24832-44. [PMID: 25012652 DOI: 10.1074/jbc.m114.565929] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The Hsp70 family protein mortalin is an essential chaperone that is frequently enriched in cancer cells and exists in various subcellular sites, including the mitochondrion, plasma membrane, endoplasmic reticulum, and cytosol. Although the molecular mechanisms underlying its multiple subcellular localizations are not yet clear, their functional significance has been revealed by several studies. In this study, we examined the nuclear fractions of human cells and found that the malignantly transformed cells have more mortalin than the normal cells. We then generated a mortalin mutant that lacked a mitochondrial targeting signal peptide. It was largely localized in the nucleus, and, hence, is called nuclear mortalin (mot-N). Functional characterization of mot-N revealed that it efficiently protects cancer cells against endogenous and exogenous oxidative stress. Furthermore, compared with the full-length mortalin overexpressing cancer cells, mot-N derivatives showed increased malignant properties, including higher proliferation rate, colony forming efficacy, motility, and tumor forming capacity both in in vitro and in vivo assays. We demonstrate that mot-N promotes carcinogenesis and cancer cell metastasis by inactivation of tumor suppressor protein p53 functions and by interaction and functional activation of telomerase and heterogeneous ribonucleoprotein K (hnRNP-K) proteins.
Collapse
Affiliation(s)
- Jihoon Ryu
- From the Cell Proliferation Research Group and Department of Biotechnology (DBT, India)-National Institute of Advanced Industrial Science and Technology (AIST, Japan) International Laboratory for Advanced Biomedicine, Tsukuba, Ibaraki 305-8562, Japan, the Department of Bioengineering, College of Engineering, Hanyang University, Seoul 133-791, Korea, and
| | - Zeenia Kaul
- From the Cell Proliferation Research Group and Department of Biotechnology (DBT, India)-National Institute of Advanced Industrial Science and Technology (AIST, Japan) International Laboratory for Advanced Biomedicine, Tsukuba, Ibaraki 305-8562, Japan, the Department of Molecular Virology, Immunology, and Medical Genetics, Ohio State University, Columbus, Ohio 43210
| | - A-Rum Yoon
- the Department of Bioengineering, College of Engineering, Hanyang University, Seoul 133-791, Korea, and
| | - Ye Liu
- From the Cell Proliferation Research Group and Department of Biotechnology (DBT, India)-National Institute of Advanced Industrial Science and Technology (AIST, Japan) International Laboratory for Advanced Biomedicine, Tsukuba, Ibaraki 305-8562, Japan
| | - Tomoko Yaguchi
- From the Cell Proliferation Research Group and Department of Biotechnology (DBT, India)-National Institute of Advanced Industrial Science and Technology (AIST, Japan) International Laboratory for Advanced Biomedicine, Tsukuba, Ibaraki 305-8562, Japan
| | - Youjin Na
- the Department of Bioengineering, College of Engineering, Hanyang University, Seoul 133-791, Korea, and
| | - Hyo Min Ahn
- From the Cell Proliferation Research Group and Department of Biotechnology (DBT, India)-National Institute of Advanced Industrial Science and Technology (AIST, Japan) International Laboratory for Advanced Biomedicine, Tsukuba, Ibaraki 305-8562, Japan, the Department of Bioengineering, College of Engineering, Hanyang University, Seoul 133-791, Korea, and
| | - Ran Gao
- From the Cell Proliferation Research Group and Department of Biotechnology (DBT, India)-National Institute of Advanced Industrial Science and Technology (AIST, Japan) International Laboratory for Advanced Biomedicine, Tsukuba, Ibaraki 305-8562, Japan
| | - Il-Kyu Choi
- the Department of Bioengineering, College of Engineering, Hanyang University, Seoul 133-791, Korea, and
| | - Chae-Ok Yun
- the Department of Bioengineering, College of Engineering, Hanyang University, Seoul 133-791, Korea, and
| | - Sunil C Kaul
- From the Cell Proliferation Research Group and Department of Biotechnology (DBT, India)-National Institute of Advanced Industrial Science and Technology (AIST, Japan) International Laboratory for Advanced Biomedicine, Tsukuba, Ibaraki 305-8562, Japan,
| | - Renu Wadhwa
- From the Cell Proliferation Research Group and Department of Biotechnology (DBT, India)-National Institute of Advanced Industrial Science and Technology (AIST, Japan) International Laboratory for Advanced Biomedicine, Tsukuba, Ibaraki 305-8562, Japan,
| |
Collapse
|
14
|
Identification of a long non-coding RNA-associated RNP complex regulating metastasis at the translational step. EMBO J 2013; 32:2672-84. [PMID: 23974796 DOI: 10.1038/emboj.2013.188] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Accepted: 07/29/2013] [Indexed: 12/31/2022] Open
Abstract
Long non-coding RNAs (lncRNAs) are a novel class of regulatory genes that play critical roles in various processes ranging from normal development to human diseases such as cancer progression. Recent studies have shown that lncRNAs regulate the gene expression by chromatin remodelling, transcription, splicing and RNA decay control, enhancer function, and epigenetic regulation. However, little is known about translation regulation by lncRNAs. We identified a translational regulatory lncRNA (treRNA) through genome-wide computational analysis. We found that treRNA is upregulated in paired clinical breast cancer primary and lymph-node metastasis samples, and that its expression stimulates tumour invasion in vitro and metastasis in vivo. Interestingly, we found that treRNA downregulates the expression of the epithelial marker E-cadherin by suppressing the translation of its mRNA. We identified a novel ribonucleoprotein (RNP) complex, consisting of RNA-binding proteins (hnRNP K, FXR1, and FXR2), PUF60 and SF3B3, that is required for this treRNA functions. Translational suppression by treRNA is dependent on the 3'UTR of the E-cadherin mRNA. Taken together, our study indicates a novel mechanism of gene regulation by lncRNAs in cancer progression.
Collapse
|
15
|
Fekete A, Kenesi E, Hunyadi-Gulyas E, Durgo H, Berko B, Dunai ZA, Bauer PI. The guanine-quadruplex structure in the human c-myc gene's promoter is converted into B-DNA form by the human poly(ADP-ribose)polymerase-1. PLoS One 2012; 7:e42690. [PMID: 22880082 PMCID: PMC3412819 DOI: 10.1371/journal.pone.0042690] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2012] [Accepted: 07/11/2012] [Indexed: 12/01/2022] Open
Abstract
The important regulatory role of the guanine-quadruplex (GQ) structure, present in the nuclease hypersensitive element (NHE) III1 region of the human c-myc (h c-myc) gene's promoter, in the regulation of the transcription of that gene has been documented. Here we present evidences, that the human nuclear poly(ADP-ribose)polymerase-1 (h PARP-1) protein participates in the regulation of the h c-myc gene expression through its interaction with this GQ structure, characterized by binding assays, fluorescence energy transfer (FRET) experiments and by affinity pull-down experiments in vitro, and by chromatin immunoprecipitation (ChIP)-qPCR analysis and h c-myc-promoter-luciferase reporter determinations in vivo. We surmise that h PARP-1 binds to the GQ structure and participates in the conversion of that structure into the transcriptionally more active B-DNA form. The first Zn-finger structure present in h PARP-1 participates in this interaction. PARP-1 might be a new member of the group of proteins participating in the regulation of transcription through their interactions with GQ structures present in the promoters of different genes.
Collapse
Affiliation(s)
- Anna Fekete
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Erzsebet Kenesi
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Eva Hunyadi-Gulyas
- Laboratory of Proteomics, Biological Research Center, Hungarian Academy of Science, Szeged, Hungary
| | - Hajnalka Durgo
- Laboratory of Proteomics, Biological Research Center, Hungarian Academy of Science, Szeged, Hungary
| | - Barbara Berko
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Zsuzsanna A. Dunai
- Department of Pathogenetics, National Institute of Oncology, Budapest, Hungary
| | - Pal I. Bauer
- Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
- * E-mail:
| |
Collapse
|
16
|
Fang X, Yoon JG, Li L, Tsai YS, Zheng S, Hood L, Goodlett DR, Foltz G, Lin B. Landscape of the SOX2 protein-protein interactome. Proteomics 2011; 11:921-34. [PMID: 21280222 DOI: 10.1002/pmic.201000419] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 11/19/2010] [Accepted: 12/05/2010] [Indexed: 01/21/2023]
Abstract
SOX2 is a key gene implicated in maintaining the stemness of embryonic and adult stem cells that appears to re-activate in several human cancers including glioblastoma multiforme. Using immunoprecipitation (IP)/MS/MS, we identified 144 proteins that are putative SOX2 interacting proteins. Of note, SOX2 was found to interact with several heterogeneous nuclear ribonucleoprotein family proteins, including HNRNPA2B1, HNRNPA3, HNRNPC, HNRNPK, HNRNPL, HNRNPM, HNRNPR, HNRNPU, as well as other ribonucleoproteins, DNA repair proteins and helicases. Gene ontology (GO) analysis revealed that the SOX2 interactome was enriched for GO terms GO:0030529 ribonucleoprotein complex and GO:0004386 helicase activity. These findings indicate that SOX2 associates with the heterogeneous nuclear ribonucleoprotein complex, suggesting a possible role for SOX2 in post-transcriptional regulation in addition to its function as a transcription factor.
Collapse
Affiliation(s)
- Xuefeng Fang
- Swedish Neuroscience Institute, Swedish Medical Center, Seattle, WA, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Mikula M, Bomsztyk K. Direct recruitment of ERK cascade components to inducible genes is regulated by heterogeneous nuclear ribonucleoprotein (hnRNP) K. J Biol Chem 2011; 286:9763-75. [PMID: 21233203 DOI: 10.1074/jbc.m110.213330] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Components of the ERK cascade are recruited to genes, but it remains unknown how they are regulated at these sites. The RNA-binding protein heterogeneous nuclear ribonucleoprotein (hnRNP) K interacts with kinases and is found along genes including the mitogen-inducible early response gene EGR-1. Here, we used chromatin immunoprecipitations to study co-recruitment of hnRNP K and ERK cascade activity along the EGR-1 gene. These measurements revealed that the spatiotemporal binding patterns of ERK cascade transducers (GRB2, SOS, B-Raf, MEK, and ERK) at the EGR-1 locus resemble both hnRNP K and RNA polymerase II (Pol II). Inhibition of EGR-1 transcription with either serum-responsive factor knockdown or 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole altered recruitment of all of the above ERK cascade components along this locus that mirrored the changes in Pol II and hnRNP K profiles. siRNA knockdown of hnRNP K decreased the levels of active MEK and ERK at the EGR-1, changes associated with decreased levels of elongating pre-mRNA and less efficient splicing. The hnRNP K dependence and pattern of ERK cascade activation at the c-MYC locus were different from at EGR-1. Ribonucleoprotein immunoprecipitations revealed that hnRNP K was associated with the EGR-1 but not c-MYC mRNAs. These data suggest a model where Pol II transcription-driven recruitment of hnRNP K along the EGR-1 locus compartmentalizes activation of the ERK cascade at these genes, events that regulate synthesis of mature mRNA.
Collapse
Affiliation(s)
- Michal Mikula
- Department of Medicine, University of Washington, Seattle, Washington 98109, USA
| | | |
Collapse
|
18
|
Wan F, Lenardo MJ. Specification of DNA binding activity of NF-kappaB proteins. Cold Spring Harb Perspect Biol 2010; 1:a000067. [PMID: 20066093 DOI: 10.1101/cshperspect.a000067] [Citation(s) in RCA: 99] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Nuclear factor-kappaB (NF-kappaB) is a pleiotropic mediator of inducible and specific gene regulation involving diverse biological activities including immune response, inflammation, cell proliferation, and death. The fine-tuning of the NF-kappaB DNA binding activity is essential for its fundamental function as a transcription factor. An increasing body of literature illustrates that this process can be elegantly and specifically controlled at multiple levels by different protein subsets. In particular, the recent identification of a non-Rel subunit of NF-kappaB itself provides a new way to understand the selective high-affinity DNA binding specificity of NF-kappaB conferred by a synergistic interaction within the whole complex. Here, we review the mechanism of the specification of DNA binding activity of NF-kappaB complexes, one of the most important aspects of NF-kappaB transcriptional control.
Collapse
Affiliation(s)
- Fengyi Wan
- Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, USA
| | | |
Collapse
|
19
|
Boyle P, Després C. Dual-function transcription factors and their entourage: unique and unifying themes governing two pathogenesis-related genes. PLANT SIGNALING & BEHAVIOR 2010; 5:629-34. [PMID: 20383056 PMCID: PMC3001550 DOI: 10.4161/psb.5.6.11570] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Much of what we, as plant molecular biologists studying gene regulation, know comes from paradigms characterized or developed in mammalian systems. Although plants, animals, and fungi have been diverging for a very long time, a great deal of the machineries and components discovered in yeast and mammals seem to have been maintained in plants. Nevertheless, despite this apparent conservation, evolutionary pressures on the mechanisms of gene regulation are likely to be different between these kingdoms, given their different environmental constraints. As such, it is imperative for plant molecular biologists to develop their own paradigms, even on seemingly conserved systems. It is with this intent that we compare and contrast the regulation of two pathogenesis-related genes, the arabidopsis PR-1 and potato PR-10a genes. The transcription factors regulating these genes present prime paradigms for the study of plant signal- and context-dependent dual-function transcription factors.
Collapse
Affiliation(s)
- Patrick Boyle
- Department of Biological Sciences, Brock University, St Catharines, ON, Canada
| | | |
Collapse
|
20
|
Wen F, Shen A, Shanas R, Bhattacharyya A, Lian F, Hostetter G, Shi J. Higher expression of the heterogeneous nuclear ribonucleoprotein k in melanoma. Ann Surg Oncol 2010; 17:2619-27. [PMID: 20499280 DOI: 10.1245/s10434-010-1121-1] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Indexed: 01/22/2023]
Abstract
BACKGROUND The heterogeneous nuclear ribonucleoprotein (hnRNP) K is an essential RNA and DNA binding protein involved in gene expression and signal transduction. The role of hnRNP K in cancer is relatively understudied. However, several cellular functions strongly indicate that hnRNP K is involved in tumorigenesis. Oncogenes c-Src, c-myc, and eIF4E are regulated by hnRNP K. We have shown an increased cytoplasmic hnRNP K in pancreatic cancer. In the present study, we investigated the altered expression of hnRNP K protein and its correlation with p-ERK in melanoma using human melanoma cell lines and tissue microarray. MATERIALS AND METHODS The protein levels of hnRNP K and p-ERK in 8 human melanoma cell lines and a melanoma progression tissue microarray containing 80 melanoma, 23 dysplastic nevi, and 14 benign nevi specimens were analyzed using Western blot and immunohistochemistry analysis. hnRNP K was knocked down by siRNA, and its effect on melanoma cells was assessed. RESULTS We showed a higher hnRNP K protein level in both melanoma cell lines and melanoma tissue specimens, which correlated with a higher c-myc expression. An increase in the cytoplasmic hnRNP K and eIF4E protein levels in melanoma cells is also seen. p-ERK level was also higher in dysplastic nevi and melanoma tissues, but did not correlate with hnRNP K protein level. We then demonstrated that knocking down of hnRNP K by siRNA inhibited melanoma cell growth and colony formation, as well as c-myc expression. CONCLUSIONS hnRNP K expression correlated with melanoma and may play a role in melanoma tumorigenesis.
Collapse
Affiliation(s)
- Fushi Wen
- Department of Surgery, Arizona Cancer Center, University of Arizona, Tucson, AZ, USA
| | | | | | | | | | | | | |
Collapse
|
21
|
Abstract
c-MYC is an important regulator of a wide array of cellular processes necessary for normal cell growth and differentiation, and its dysregulation is one of the hallmarks of many cancers. Consequently, understanding c-MYC transcriptional activation is critical for understanding developmental and cancer biology, as well as for the development of new anticancer drugs. The nuclease hypersensitive element (NHE) III(1) region of the c-MYC promoter has been shown to be particularly important in regulating c-MYC expression. Specifically, the formation of a G-quadruplex structure appears to promote repression of c-MYC transcription. This review focuses on what is known about the formation of a G-quadruplex in the NHE III(1) region of the c-MYC promoter, as well as on those factors that are known to modulate its formation. Last, we discuss the development of small molecules that stabilize or induce the formation of G-quadruplex structures and could potentially be used as anticancer agents.
Collapse
|
22
|
Yao Y, Jia XY, Tian HY, Jiang YX, Xu GJ, Qian QJ, Zhao FK. Comparative proteomic analysis of colon cancer cells in response to oxaliplatin treatment. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2009; 1794:1433-40. [PMID: 19520192 DOI: 10.1016/j.bbapap.2009.06.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 01/05/2009] [Revised: 06/02/2009] [Accepted: 06/02/2009] [Indexed: 11/18/2022]
Abstract
Colon cancer is one of the most common malignancies in the world. Oxaliplatin, a third-generation platinum compound, is widely used in clinical chemotherapy of colon cancer. Although the mechanisms of the antitumor effect of Oxaliplatin have been investigated in recent years, the proteomic changes that are associated with the cellular response to this compound are poorly understood. In this study, we performed a comparative proteomic analysis to survey the global changes in protein expression levels after Oxaliplatin treatment in three colon cancer cell lines: HT29, SW620, and LoVo. Two-dimensional gel electrophoresis coupled with MALDI-TOF/TOF mass spectrometry revealed 57, 48, and 53 differentially expressed proteins in the three cell lines (HT29, SW620 and LoVo, respectively) after Oxaliplatin treatment. Of these proteins, 21 overlapped among all three cell lines. These overlapping proteins participate in many cellular processes, such as apoptosis, signal transduction, transcription and translation, cell structural organization, and metabolism. Additionally, the expression levels of ezrin (EZRI), heat-shock protein beta-1 (HSPB1), translationally controlled tumor protein (TCTP), and cell division control protein 2 homolog (CDC2) were confirmed by immunoblotting. This is the first direct proteomic analysis of Oxaliplatin-treated colon cancer cells. Several interesting proteins that we found warrant further investigation owing to their potential significant functions in the antitumor effect of Oxaliplatin.
Collapse
Affiliation(s)
- Yi Yao
- College of Life Science, Zhejiang Sci-Tech University, Hangzhou 310018, China
| | | | | | | | | | | | | |
Collapse
|
23
|
Heterogeneous nuclear ribonucleoprotein K: altered pattern of expression associated with diagnosis and prognosis of prostate cancer. Br J Cancer 2009; 100:1608-16. [PMID: 19401687 PMCID: PMC2696760 DOI: 10.1038/sj.bjc.6605057] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Using proteomic analysis of the nuclear matrix (NM), we found that heterogeneous nuclear ribonucleoprotein K (hnRNP K), a member of the hnRNP family with pleiotropic functions, was differentially expressed in prostate cancer (PCa) tissues. This study aimed to characterise the expression of hnRNP K and its subcellular localisation in PCa, utilising immunohistochemical and quantitative western blot techniques. Furthermore, the hnRNP K expression was studied in human PCa cell lines in order to determine its modulation by bicalutamide, the anti-androgen widely used in PCa therapy. Immunohistochemical staining of paraffin-embedded tissues showed that hnRNP K was overexpressed in PCa, where it was localised both in the cytoplasm and in the nucleus. Staining of non-tumour tissues showed exclusively nuclear localisation and a less intense or absent signal. Immunoblot analysis demonstrated that the hnRNP K level within the NM was higher in PCa compared with non-tumour tissues and closely correlated with Gleason score (P=0.008). Higher expression within the NM was significantly (P=0.032) associated with poor prognosis. In two-dimensional western blot analysis hnRNP K presented several isoforms; the one with pI 5.1 was the most differently expressed between non-tumour and PCa tissues. Preliminary results indicate that hnRNP K can be modulated in vitro by a non-steroidal anti-androgen. Taken together, our findings suggest that hnRNP K has potential implications at the diagnostic, prognostic and therapeutic levels in PCa.
Collapse
|
24
|
González-Lamothe R, Boyle P, Dulude A, Roy V, Lezin-Doumbou C, Kaur GS, Bouarab K, Després C, Brisson N. The transcriptional activator Pti4 is required for the recruitment of a repressosome nucleated by repressor SEBF at the potato PR-10a gene. THE PLANT CELL 2008; 20:3136-47. [PMID: 19028963 PMCID: PMC2613659 DOI: 10.1105/tpc.108.061721] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Revised: 10/22/2008] [Accepted: 11/03/2008] [Indexed: 05/22/2023]
Abstract
Transcriptional reprogramming is critical for plant disease resistance responses. In potato (Solanum tuberosum), the marker gene PATHOGENESIS-RELATED-10a (PR-10a) is transcriptionally activated by pathogens, wounding, or elicitor treatment. Activation of PR-10a requires the recruitment of the activator Why1 to its promoter. In addition, PR-10a is negatively regulated by the repressor SEBF (for Silencer Element Binding Factor). Here, we show through a yeast two-hybrid screen that SEBF interacts with Pti4, which has been shown to be a transcriptional activator. SEBF recruits Pti4 via its consensus sequence-type RNA binding domain, while Pti4 is recruited to SEBF by means of its ethylene-response factor domain. In vivo plant transcription assays confirmed that SEBF interacts with Pti4 to form a repressosome, showing that Pti4 can also play a role in transcriptional repression. Chromatin immunoprecipitation revealed that both SEBF and Pti4 are recruited to the PR-10a promoter in uninduced conditions only and that the recruitment of Pti4 is dependent on the presence of SEBF, consistent with the fact that there is no Pti4 consensus binding site in PR-10a. Unexpectedly, we also demonstrated that recruitment of SEBF was dependent on the presence of Pti4, thereby explaining why SEBF, itself a repressor, requires Pti4 for its repressing function.
Collapse
|
25
|
Flanagin S, Nelson JD, Castner DG, Denisenko O, Bomsztyk K. Microplate-based chromatin immunoprecipitation method, Matrix ChIP: a platform to study signaling of complex genomic events. Nucleic Acids Res 2008; 36:e17. [PMID: 18203739 PMCID: PMC2241906 DOI: 10.1093/nar/gkn001] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The chromatin immunoprecipitation (ChIP) assay is a major tool in the study of genomic processes in vivo. This and other methods are revealing that control of gene expression, cell division and DNA repair involves multiple proteins and great number of their modifications. ChIP assay is traditionally done in test tubes limiting the ability to study signaling of the complex genomic events. To increase the throughput and to simplify the assay we have developed a microplate-based ChIP (Matrix ChIP) method, where all steps from immunoprecipitation to DNA purification are done in microplate wells without sample transfers. This platform has several important advantages over the tube-based assay including very simple sample handling, high throughput, improved sensitivity and reproducibility, and potential for automation. 96 ChIP measurements including PCR can be done by one researcher in one day. We illustrate the power of Matrix ChIP by parallel profiling 80 different chromatin and transcription time-course events along an inducible gene including transient recruitment of kinases.
Collapse
Affiliation(s)
- Steve Flanagin
- UW Medicine Lake Union, Department of Medicine, University of Washington, Seattle, WA 98109, USA
| | | | | | | | | |
Collapse
|
26
|
Nelson JD, Flanagin S, Kawata Y, Denisenko O, Bomsztyk K. Transcription of laminin gamma1 chain gene in rat mesangial cells: constitutive and inducible RNA polymerase II recruitment and chromatin states. Am J Physiol Renal Physiol 2008; 294:F525-33. [PMID: 18184742 DOI: 10.1152/ajprenal.00299.2007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The laminin gamma1 chain, a critical component of the extracellular matrix, is encoded by the 125-kb-long Lamc1 locus. We profiled RNA polymerase II (Pol II) and histone modifications along the Lamc1 locus to explore transcription of this gene in its native chromatin environment. Treatment with 12-O-tetradecanoylphorbol-13-acetate increased Lamc1 mRNA in rat mesangial cells (RMC). This increase was matched by an increase in Pol II density along the entire length of the Lamc1 locus. In contrast, in the hepatocarcinoma cell line (HTC-IR) an increase in Pol II density was restricted to the promoter and was not followed by mRNA induction. The pattern of histone H3 methylation was similar for both cell types but an increase in H3 lysine 9 acetylation observed at the 5'-end was weaker in HTC-IR cells than in RMC. All of the histone modifications showed spatial patterns where levels differed greatly between the 5'- and 3'-ends of Lamc1. Conversely, at the short, highly induced egr-1 gene the differences in chromatin marks between the 5'- and 3'-ends were much smaller. The results of this study suggest that 1) Lamc1 transcription can be controlled after transcription initiation, to our knowledge, the first time this has been shown in an extracellular matrix gene, and 2) the length of a gene is a factor that can affect the chromatin environment for Pol II elongation.
Collapse
Affiliation(s)
- Joel D Nelson
- Molecular and Cellular Biology Program, University of Washington Medicine Lake Union, Seattle, Washington 98109, USA
| | | | | | | | | |
Collapse
|
27
|
|
28
|
Denisenko O, Bomsztyk K. Epistatic interaction between the K-homology domain protein HEK2 and SIR1 at HMR and telomeres in yeast. J Mol Biol 2007; 375:1178-87. [PMID: 18067921 DOI: 10.1016/j.jmb.2007.11.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2007] [Revised: 10/30/2007] [Accepted: 11/01/2007] [Indexed: 10/22/2022]
Abstract
In budding yeast, telomeres, the ribosomal DNA array, and HM loci are transcriptionally silenced by chromatin complexes containing Sir proteins. Hek2, a protein containing three evolutionary conserved RNA-binding K-homology domains, was identified as a suppressor of telomeric silencing [telomeric position effect (TPE)]. To explore the mechanisms of Hek2p action in gene silencing, we examined its relationship with Sir proteins. This search revealed an epistatic interaction between HEK2 and SIR1 at telomeres. Both single mutations, sir1Delta and hek2Delta, enhanced TPE, whereas the effect of double mutation, sir1Delta hek2Delta, did not exceed that of the single mutations. The results of chromatin immunoprecipitation analysis demonstrate that the TPE enhancement observed in these mutants is associated with increased binding of Sir2 protein to telomeres. At the HMR locus, hek2Delta rescues the silencing defect caused by sir1Delta mutation and reverses the loss of Sir2p and Sir3p. These data suggest that the epistatic interaction of HEK2 and SIR1 reflects competition between telomeres and HMR for Sir2/3 factors where HEK2 acts to suppress silencing. Because chromatin immunoprecipitation analysis reveals the presence of Hek2p at a subtelomeric region and HMR, its silencing effects at these loci are likely direct. These observations suggest that HEK2 regulates the composition of Sir complexes at HMR and telomeres.
Collapse
Affiliation(s)
- Oleg Denisenko
- Department of Medicine, Room 242, University of Washington, 815 Mercer Street, Seattle, WA 98109, USA.
| | | |
Collapse
|
29
|
Nelson JD, Denisenko O, Bomsztyk K. Protocol for the fast chromatin immunoprecipitation (ChIP) method. Nat Protoc 2007; 1:179-85. [PMID: 17406230 DOI: 10.1038/nprot.2006.27] [Citation(s) in RCA: 615] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Chromatin and transcriptional processes are among the most intensively studied fields of biology today. The introduction of chromatin immunoprecipitations (ChIP) represents a major advancement in this area. This powerful method allows researchers to probe specific protein-DNA interactions in vivo and to estimate the density of proteins at specific sites genome-wide. We have introduced several improvements to the traditional ChIP assay, which simplify the procedure, greatly reducing the time and labor required to complete the assay. The simplicity of the method yields highly reproducible results. Our improvements facilitate the probing of multiple proteins in a single experiment, which allows for the simultaneous monitoring of many genomic events. This method is particularly useful in kinetic studies where multiple samples are processed at the same time. Starting with sheared chromatin, PCR-ready DNA can be isolated from 16-24 ChIP samples in 4-6 h using the fast method.
Collapse
Affiliation(s)
- Joel D Nelson
- Molecular and Cellular Biology Program, University of Washington, Seattle, Washington 98109, USA
| | | | | |
Collapse
|
30
|
Roychoudhury P, Paul RR, Chowdhury R, Chaudhuri K. HnRNP E2 is downregulated in human oral cancer cells and the overexpression of hnRNP E2 induces apoptosis. Mol Carcinog 2007; 46:198-207. [PMID: 17219427 DOI: 10.1002/mc.20265] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Human hnRNP genes have been reported to be involved in human malignancies and several hnRNPs are promising biomarkers of lung, head and neck, colon, breast, and pancreatic cancers. The present study investigated the clinicopathologic and biological significance of hnRNP E2 gene expression in oral cancer. Human hnRNP E2 was significantly downregulated in oral cancer tissues compared to normal one (P<0.0001) as determined by quantitative real-time reverse transcription PCR. The expression of hnRNP E2 is correlated with histology, being lower in moderate and poorly differentiated squamous cell carcinoma (SCC) compared to well-differentiated SCC. Transient transfection of hnRNP E2 in cancerous cell lines resulted in reduced cell viability and increased apoptotic nuclei. Compared to control transfectants, cells with higher expression showed an increase in the number of apoptotic cells by annexin-PI staining and an increase in caspase activity. The present study thus implicates downregulation of hnRNP E2 as a novel mechanism to enhance the resistance of cancer cells to apoptosis.
Collapse
Affiliation(s)
- Paromita Roychoudhury
- Human Genetics & Genomics Group, Indian Institute of Chemical Biology, Jadavpur, Kolkata 700032, India
| | | | | | | |
Collapse
|
31
|
Adolph D, Flach N, Mueller K, Ostareck DH, Ostareck-Lederer A. Deciphering the cross talk between hnRNP K and c-Src: the c-Src activation domain in hnRNP K is distinct from a second interaction site. Mol Cell Biol 2007; 27:1758-70. [PMID: 17178840 PMCID: PMC1820454 DOI: 10.1128/mcb.02014-06] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2006] [Accepted: 12/04/2006] [Indexed: 11/20/2022] Open
Abstract
The protein tyrosine kinase c-Src is regulated by two intramolecular interactions. The repressed state is achieved through the interaction of the Src homology 2 (SH2) domain with the phosphorylated C-terminal tail and the association of the SH3 domain with a polyproline type II helix formed by the linker region between SH2 and the kinase domain. hnRNP K, the founding member of the KH domain protein family, is involved in chromatin remodeling, regulation of transcription, and translation of specific mRNAs and is a target in different signal transduction pathways. In particular, it functions as a specific activator and a substrate of the tyrosine kinase c-Src. Here we address the question how hnRNP K interacts with and activates c-Src. We define the proline residues in hnRNP K in the proline-rich motifs P2 (amino acids [aa] 285 to 297) and P3 (aa 303 to 318), which are necessary and sufficient for the specific activation of c-Src, and we dissect the amino acid sequence (aa 216 to 226) of hnRNP K that mediates a second interaction with c-Src. Our findings indicate that the interaction with c-Src and the activation of the kinase are separable functions of hnRNP K. hnRNP K acts as a scaffold protein that integrates signaling cascades by facilitating the cross talk between kinases and factors that mediate nucleic acid-directed processes.
Collapse
Affiliation(s)
- Dörte Adolph
- Institute of Biochemistry, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3, 06120 Halle (Saale), Germany
| | | | | | | | | |
Collapse
|
32
|
Hatakeyama H, Kondo T, Fujii K, Nakanishi Y, Kato H, Fukuda S, Hirohashi S. Protein clusters associated with carcinogenesis, histological differentiation and nodal metastasis in esophageal cancer. Proteomics 2006; 6:6300-16. [PMID: 17133371 DOI: 10.1002/pmic.200600488] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
We examined the proteomic background of esophageal cancer. We used laser microdissection to obtain tumor tissues from 72 esophageal squamous cell carcinoma cases and adjacent normal tissues in 57 of these cases. The 2D-DIGE generated quantitative expression profiles with 1730 protein spots. Based on the intensity of the protein spots, unsupervised classification distinguished the tumor tissues from their normal counterparts, and subdivided the tumor tissues according to their histological differentiation. We identified 498 protein spots with altered intensity in the tumor tissues, which protein identification by LC-MS/MS showed to correspond to 217 gene products. We also found 41 protein spots that were associated with nodal metastasis, and identified 33 proteins corresponding to the spots, including cancer-associated proteins such as alpha-actinin 4, hnRNP K, periplakin, squamous cell carcinoma antigen 1 and NudC. The identified cancer-associated proteins have been previously reported to be individually involved in a range of cancer types, and our study observed them collectively in a single type of malignancy, esophageal cancer. As the identified proteins are involved in important biological processes such as cytoskeletal/structural organization, transportation, chaperon, oxidoreduction, transcription and signal transduction, they may function in a coordinate manner in carcinogenesis and tumor progression of esophageal cancer.
Collapse
Affiliation(s)
- Hiromitsu Hatakeyama
- Proteome Bioinformatics Project, National Cancer Center Research Institute, Tokyo, Japan
| | | | | | | | | | | | | |
Collapse
|
33
|
Kwiek NC, Thacker DF, Datto MB, Megosh HB, Haystead TAJ. PITK, a PP1 targeting subunit that modulates the phosphorylation of the transcriptional regulator hnRNP K. Cell Signal 2006; 18:1769-78. [PMID: 16564677 DOI: 10.1016/j.cellsig.2006.01.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2006] [Revised: 01/24/2006] [Accepted: 01/25/2006] [Indexed: 12/20/2022]
Abstract
Protein phosphatase-1 (PP1), through interactions with substrate targeting subunits, plays critical roles in the regulation of numerous cellular processes. Herein, we describe a newly identified regulatory subunit (PITK; Phosphatase Interactor Targeting K protein) that specifically targets the catalytic subunit of PP1 to nuclear foci to selectively bind and dephosphorylate the transcriptional regulator heterogeneous nuclear ribonucleoprotein K (hnRNP K) at a regulatory S284 site. Additionally, PITK is phosphorylated in vivo at S1013 and S1017, residues that flank or reside within the PP1C-binding motif, and this phosphorylation negatively regulates the binding of the phosphatase to PITK. A mutant variant, S1013,1017A-PITK, when expressed in intact cells, exhibited an increase in native PP1 binding and elicited a more profound dephosphorylation of hnRNPK at S284. A global analysis of transcription by Affymetrix microarray revealed that the expression of PITK resulted in the altered expression of 47 genes, including a marked induction of MEK5 (>14-fold, p<0.007). Additionally, the effects of PITK and S1013,1017A-PITK on transcription could be modulated by the co-expression of hnRNP K. Taken together, our findings provide a putative mechanism by which transcriptional activity of hnRNP K can be discretely controlled through the regulation of PP1 activity.
Collapse
Affiliation(s)
- Nicole C Kwiek
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Box 3813, Durham, NC 27710, USA
| | | | | | | | | |
Collapse
|
34
|
Wei CC, Zhang SL, Chen YW, Guo DF, Ingelfinger JR, Bomsztyk K, Chan JSD. Heterogeneous Nuclear Ribonucleoprotein K Modulates Angiotensinogen Gene Expression in Kidney Cells. J Biol Chem 2006; 281:25344-55. [PMID: 16837467 DOI: 10.1074/jbc.m601945200] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The present studies aimed to identify the 70-kDa nuclear protein that binds to an insulin-responsive element in the rat angiotensinogen gene promoter and to define its action on angiotensinogen gene expression. Nuclear proteins were isolated from rat kidney proximal tubular cells and subjected to two-dimensional electrophoresis. The 70-kDa nuclear protein was detected by Southwestern blotting and subsequently identified by mass spectrometry, which revealed that it was identical to 65-kDa heterogeneous nuclear ribonucleoprotein K (hnRNP K). hnRNP K bound to the insulin-responsive element of the rat angiotensinogen gene was revealed by a gel mobility shift assay and chromatin immunoprecipitation assay. hnRNP K inhibited angiotensinogen mRNA expression and promoter activity. In contrast, hnRNP K down-expression by small interference RNA enhanced angiotensinogen mRNA expression. Moreover, hnRNP K interacted with hnRNP F in pulldown and co-immunoprecipitation assays. Co-transfection of hnRNP K and hnRNP F further suppressed angiotensinogen mRNA expression. Finally, in vitro and in vivo studies demonstrated that high glucose increases and insulin inhibits hnRNP K expression in rat kidney proximal tubular cells. In conclusion, our experiments revealed that hnRNP K is a nuclear protein that binds to the insulin-responsive element of the rat angiotensinogen gene promoter and modulates angiotensinogen gene transcription in the kidney.
Collapse
Affiliation(s)
- Chih-Chang Wei
- Centre de Recherche, Centre Hospitalier de l'Université de Montréal-Hôtel-Dieu, Montreal, Quebec H2W 1T8, Canada
| | | | | | | | | | | | | |
Collapse
|
35
|
Malik AK, Flock KE, Godavarthi CL, Loh HH, Ko JL. Molecular basis underlying the poly C binding protein 1 as a regulator of the proximal promoter of mouse mu-opioid receptor gene. Brain Res 2006; 1112:33-45. [PMID: 16904079 DOI: 10.1016/j.brainres.2006.07.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2005] [Revised: 06/07/2006] [Accepted: 07/05/2006] [Indexed: 11/19/2022]
Abstract
Previous studies showed poly C binding protein 1 (PCBP) participating in the mu-opioid receptor (MOR) gene regulation via binding to a single-stranded (ss) DNA element. In this report, we therefore investigate the molecular basis of PCBP regulating the MOR gene expression. Various truncated PCBPs, including one domain (KH1, KH2, variable or KH3), two- (K12, K2v or Kv3) or three-sequential domains (K12v or K2v3), were constructed. The MOR ssDNA binding abilities of these truncated PCBPs were examined using electrophoretic mobility shift assay (EMSA). KH1 domain possessed a strong MOR ssDNA binding activity. Variable domain displayed no binding, and KH2 or KH3 domain possessed a weak MOR ssDNA binding activity. Binding of two-domain PCBPs indicated an additive effect of two-domain combinations. Interestingly, K2v3, a three-domain PCBP, displayed as strong ssDNA binding as that of K12v, suggesting synergism of KH2, KH3 and variable domains for the binding activity. Functional analysis demonstrated one-domain PCBPs exhibiting no transactivation on the MOR proximal promoter. Two-domain PCBPs displayed approximately 20% activity, while three-domain PCBPs displayed 70%-85% of full-length PCBP activity. Taken together, these results suggested that no single domain possessed sufficient functional activity to serve as an independent transactivation domain, and the combination of three sequential domains was necessary for its optimal activity to activate the MOR proximal promoter. In summary, our data suggested that cooperativity of three sequential domains is essential for PCBP functioning as a MOR gene regulator. Various ways in which this cooperativity could occur are discussed.
Collapse
MESH Headings
- Animals
- Base Sequence
- Carrier Proteins/physiology
- Cell Line, Tumor
- DNA-Binding Proteins
- Electrophoretic Mobility Shift Assay/methods
- Gene Expression Regulation/physiology
- Methionine/metabolism
- Mice
- Neuroblastoma
- Phosphorus Isotopes/metabolism
- Promoter Regions, Genetic/physiology
- Protein Binding/drug effects
- Protein Binding/physiology
- Protein Structure, Tertiary/physiology
- RNA, Messenger/metabolism
- RNA-Binding Proteins
- Receptors, Opioid, mu/genetics
- Receptors, Opioid, mu/metabolism
- Regulatory Sequences, Nucleic Acid
- Reverse Transcriptase Polymerase Chain Reaction/methods
- Transcription, Genetic
- Transfection/methods
Collapse
Affiliation(s)
- Adnan K Malik
- Department of Biology, Seton Hall University, 208 McNulty Hall, 400 South Orange Ave. South Orange, NJ 07079, USA
| | | | | | | | | |
Collapse
|
36
|
Blanchette AR, Fuentes Medel YF, Gardner PD. Cell-type-specific and developmental regulation of heterogeneous nuclear ribonucleoprotein K mRNA in the rat nervous system. Gene Expr Patterns 2006; 6:596-606. [PMID: 16488668 DOI: 10.1016/j.modgep.2005.11.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2005] [Revised: 11/08/2005] [Accepted: 11/29/2005] [Indexed: 11/24/2022]
Abstract
Heterogeneous nuclear ribonucleoprotein K (hnRNP K) was originally identified as being part of the hnRNP particle. hnRNP K has subsequently been shown to be involved in a number of fundamental biological processes such as RNA transport and processing as well as transcription and translation. In addition, hnRNP K is an integral player in a variety of intracellular signal transduction pathways. Not surprisingly given this broad array of cellular functions, hnRNP K is a highly interactive protein binding directly to both single- and double-stranded nucleic acids as well as numerous signaling proteins. Interestingly, earlier studies demonstrated that hnRNP K protein is not ubiquitously expressed and does not exist in a fixed stoichiometry with other hnRNP proteins. We have extended this earlier work and report here the spatially- and developmentally-regulated expression of hnRNP K mRNA during development of the rat nervous system. In the central nervous system, hnRNP K mRNA expression gradually decreases during development until it is restricted to a very limited number of structures including most notably the hippocampus and the retina. Immunohistochemical data indicate that hnRNP K protein expression closely parallels hnRNP K mRNA expression. In contrast to the central nervous system, hnRNP K in the peripheral nervous system remains high throughout embryonic development with dramatic expression in several peripheral ganglia.
Collapse
Affiliation(s)
- Adam R Blanchette
- Department of Molecular Medicine, University of Texas Health Science Center, San Antonio, TX 78245, USA
| | | | | |
Collapse
|
37
|
Mikula M, Dzwonek A, Karczmarski J, Rubel T, Dadlez M, Wyrwicz LS, Bomsztyk K, Ostrowski J. Landscape of the hnRNP K protein-protein interactome. Proteomics 2006; 6:2395-406. [PMID: 16518874 DOI: 10.1002/pmic.200500632] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The heterogeneous nuclear ribonucleoprotein K is an ancient RNA/DNA-binding protein that is involved in multiple processes that compose gene expression. The pleiotropic action of K protein reflects its ability to interact with different classes of factors, interactions that are regulated by extracellular signals. We used affinity purification and MS to better define the repertoire of K protein partners. We identified a large number of new K protein partners, some typically found in subcellular compartments, such as plasma membrane, where K protein has not previously been seen. Electron microscopy showed K protein in the nucleus, cytoplasm, mitochondria, and in vicinity of plasma membrane. These observations greatly expanded the view of the landscape of K protein-protein interaction and provide new opportunities to explore signal transduction and gene expression in several subcellular compartments.
Collapse
Affiliation(s)
- Michał Mikula
- Department of Gastroenterology, Medical Center for Postgraduate Education and Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw, Poland
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Klimek-Tomczak K, Mikula M, Dzwonek A, Paziewska A, Karczmarski J, Hennig E, Bujnicki JM, Brągoszewski P, Denisenko O, Bomsztyk K, Ostrowski J. Editing of hnRNP K protein mRNA in colorectal adenocarcinoma and surrounding mucosa. Br J Cancer 2006; 94:586-92. [PMID: 16404425 PMCID: PMC2361188 DOI: 10.1038/sj.bjc.6602938] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The heterogeneous nuclear ribonucleoprotein K (hnRNP K) protein is an RNA-binding protein involved in many processes that compose gene expression. K protein is upregulated in the malignant processes and has been shown to modulate the expression of genes involved in mitogenic responses and tumorigenesis. To explore the possibility that there are alternative isoforms of K protein expressed in colon cancer, we amplified and sequenced K protein mRNA that was isolated from colorectal cancers as well as from normal tissues surrounding the tumours. Sequencing revealed a single G-to-A base substitution at position 274 that was found in tumours and surrounding mucosa, but not in individuals that had no colorectal tumour. This substitution most likely reflects an RNA editing event because it was not found in the corresponding genomic DNAs. Sequencing of RNA from normal colonic mucosa of patients with prior resection of colorectal cancer revealed only the wild-type K protein transcript, indicating that G274A isoform is tumour related. To our knowledge, this is the first example of an RNA editing event in cancer and its surrounding tissue, a finding that may offer a new diagnostic and treatment marker.
Collapse
Affiliation(s)
- K Klimek-Tomczak
- Department of Gastroenterology, Medical Center for Postgraduate Education and Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, ul. Roentgena 5, Warsaw 02-781, Poland
| | - M Mikula
- Department of Gastroenterology, Medical Center for Postgraduate Education and Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, ul. Roentgena 5, Warsaw 02-781, Poland
| | - A Dzwonek
- Department of Gastroenterology, Medical Center for Postgraduate Education and Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, ul. Roentgena 5, Warsaw 02-781, Poland
| | - A Paziewska
- Department of Gastroenterology, Medical Center for Postgraduate Education and Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, ul. Roentgena 5, Warsaw 02-781, Poland
| | - J Karczmarski
- Department of Gastroenterology, Medical Center for Postgraduate Education and Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, ul. Roentgena 5, Warsaw 02-781, Poland
| | - E Hennig
- Department of Gastroenterology, Medical Center for Postgraduate Education and Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, ul. Roentgena 5, Warsaw 02-781, Poland
| | - J M Bujnicki
- Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology, Warsaw 02-109, Poland
| | - P Brągoszewski
- Department of Gastroenterology, Medical Center for Postgraduate Education and Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, ul. Roentgena 5, Warsaw 02-781, Poland
| | - O Denisenko
- Department of Medicine, UW Medicine Lake Union, University of Washington, Seattle, WA 98109, USA
| | - K Bomsztyk
- Department of Medicine, UW Medicine Lake Union, University of Washington, Seattle, WA 98109, USA
| | - J Ostrowski
- Department of Gastroenterology, Medical Center for Postgraduate Education and Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, ul. Roentgena 5, Warsaw 02-781, Poland
- Department of Gastroenterology, Medical Center for Postgraduate Education and Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, ul. Roentgena 5, Warsaw 02-781, Poland. E-mail:
| |
Collapse
|
39
|
Dzwonek A, Mikula M, Ostrowski J. The diverse involvement of heterogeneous nuclear ribonucleoprotein K in mitochondrial response to insulin. FEBS Lett 2006; 580:1839-45. [PMID: 16519889 DOI: 10.1016/j.febslet.2006.02.043] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2006] [Revised: 02/15/2006] [Accepted: 02/16/2006] [Indexed: 01/06/2023]
Abstract
Heterogeneous nuclear ribonucleoprotein K (hnRNP K protein) is an RNA/DNA-binding protein that acts in several compartments, including mitochondria. It integrates cellular signaling cascades with multiple processes of gene expression mechanisms. Our studies demonstrate that: (1) insulin activates the import of hnRNP K protein into mitochondria in vitro and in vivo; (2) overexpression of hnRNP K protein modulates insulin-activated mitochondrial gene expression; and (3) insulin treatment stimulates binding of hnRNP K protein to mitochondrial DNA. Based on these and our previously reported results we conclude that hnRNP K protein may be a mediator of mitochondrial response to insulin.
Collapse
Affiliation(s)
- Artur Dzwonek
- Department of Gastroenterology, Medical Center for Postgraduate Education and Maria Skłodowska-Curie Memorial Cancer Center and Institute of Oncology, Roentgena Street 5, 02-781 Warsaw, Poland
| | | | | |
Collapse
|
40
|
Abstract
Chromatin immunoprecipitation (ChIP) is a widely used method to explore in vivo interactions between proteins and DNA. The ChIP assay takes several days to complete, involves several tube transfers and uses either phenol–chlorophorm or spin columns to purify DNA. The traditional ChIP method becomes a challenge when handling multiple samples. We have developed an efficient and rapid Chelex resin-based ChIP procedure that dramatically reduces time of the assay and uses only a single tube to isolate PCR-ready DNA. This method greatly facilitates the probing of chromatin changes over many time points with several antibodies in one experiment.
Collapse
Affiliation(s)
- Joel D. Nelson
- Molecular and Cellular Biology Program, University of WashingtonSeattle, WA 98109, USA
- UW Medicine Lake Union Research, University of WashingtonSeattle, WA 98109, USA
| | - Oleg Denisenko
- UW Medicine Lake Union Research, University of WashingtonSeattle, WA 98109, USA
| | - Pavel Sova
- UW Medicine Lake Union Research, University of WashingtonSeattle, WA 98109, USA
| | - Karol Bomsztyk
- Molecular and Cellular Biology Program, University of WashingtonSeattle, WA 98109, USA
- UW Medicine Lake Union Research, University of WashingtonSeattle, WA 98109, USA
- To whom correspondence should be addressed at UW Medicine Lake Union, Box 358050, University of Washington, Seattle, WA 98109, USA. Tel: +1 206 616 7949; Fax: +1 206 616 8591;
| |
Collapse
|
41
|
Moumen A, Masterson P, O'Connor MJ, Jackson SP. hnRNP K: An HDM2 Target and Transcriptional Coactivator of p53 in Response to DNA Damage. Cell 2005; 123:1065-78. [PMID: 16360036 DOI: 10.1016/j.cell.2005.09.032] [Citation(s) in RCA: 263] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2005] [Revised: 08/10/2005] [Accepted: 09/07/2005] [Indexed: 02/04/2023]
Abstract
In response to DNA damage, mammalian cells trigger the p53-dependent transcriptional induction of factors that regulate DNA repair, cell-cycle progression, or cell survival. Through differential proteomics, we identify heterogeneous nuclear ribonucleoprotein K (hnRNP K) as being rapidly induced by DNA damage in a manner that requires the DNA-damage signaling kinases ATM or ATR. Induction of hnRNP K ensues through the inhibition of its ubiquitin-dependent proteasomal degradation mediated by the ubiquitin E3 ligase HDM2/MDM2. Strikingly, hnRNP K depletion abrogates transcriptional induction of p53 target genes and causes defects in DNA-damage-induced cell-cycle-checkpoint arrests. Furthermore, in response to DNA damage, p53 and hnRNP K are recruited to the promoters of p53-responsive genes in a mutually dependent manner. These findings establish hnRNP K as a new HDM2 target and show that, by serving as a cofactor for p53, hnRNP K plays key roles in coordinating transcriptional responses to DNA damage.
Collapse
Affiliation(s)
- Abdeladim Moumen
- The Wellcome Trust and Cancer Research UK Gurdon Institute and Department of Zoology, Cambridge University, Tennis Court Road, Cambridge CB2 1QN, United Kingdom
| | | | | | | |
Collapse
|
42
|
Carpenter B, MacKay C, Alnabulsi A, MacKay M, Telfer C, Melvin WT, Murray GI. The roles of heterogeneous nuclear ribonucleoproteins in tumour development and progression. Biochim Biophys Acta Rev Cancer 2005; 1765:85-100. [PMID: 16378690 DOI: 10.1016/j.bbcan.2005.10.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2005] [Revised: 10/18/2005] [Accepted: 10/19/2005] [Indexed: 10/25/2022]
Abstract
The heterogeneous nuclear ribonucleoproteins (hnRNP) are a family of proteins which share common structural domains, and extensive research has shown that they have central roles in DNA repair, telomere biogenesis, cell signaling and in regulating gene expression at both transcriptional and translational levels. Through these key cellular functions, individual hnRNPs have a variety of potential roles in tumour development and progression including the inhibition of apoptosis, angiogenesis and cell invasion. The aims of this review are to provide an overview of the multi functional roles of the hnRNPs, and how such roles implicate this family as regulators of tumour development. The different stages of tumour development that are potentially regulated by the hnRNPs along with their aberrant expression profiles in tumour tissues will also be discussed.
Collapse
Affiliation(s)
- Brian Carpenter
- Department of Pathology, University of Aberdeen, Foresterhill, Aberdeen AB25 2ZD, UK
| | | | | | | | | | | | | |
Collapse
|
43
|
Lynch M, Chen L, Ravitz MJ, Mehtani S, Korenblat K, Pazin MJ, Schmidt EV. hnRNP K binds a core polypyrimidine element in the eukaryotic translation initiation factor 4E (eIF4E) promoter, and its regulation of eIF4E contributes to neoplastic transformation. Mol Cell Biol 2005; 25:6436-53. [PMID: 16024782 PMCID: PMC1190351 DOI: 10.1128/mcb.25.15.6436-6453.2005] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2004] [Revised: 12/23/2004] [Accepted: 05/02/2005] [Indexed: 11/20/2022] Open
Abstract
Translation initiation factor eukaryotic translation initiation factor 4E (eIF4E) plays a key role in regulation of cellular proliferation. Its effects on the m7GpppN mRNA cap are critical because overexpression of eIF4E transforms cells, and eIF4E function is rate-limiting for G1 passage. Although we identified eIF4E as a c-Myc target, little else is known about its transcriptional regulation. Previously, we described an element at position -25 (TTACCCCCCCTT) that was critical for eIF4E promoter function. Here we report that this sequence (named 4EBE, for eIF4E basal element) functions as a basal promoter element that binds hnRNP K. The 4EBE is sufficient to replace TATA sequences in a heterologous reporter construct. Interactions between 4EBE and upstream activator sites are position, distance, and sequence dependent. Using DNA affinity chromatography, we identified hnRNP K as a 4EBE-binding protein. Chromatin immunoprecipitation, siRNA interference, and hnRNP K overexpression demonstrate that hnRNP K can regulate eIF4E mRNA. Moreover, hnRNP K increased translation initiation, increased cell division, and promoted neoplastic transformation in an eIF4E-dependent manner. hnRNP K binds the TATA-binding protein, explaining how the 4EBE might replace TATA in the eIF4E promoter. hnRNP K is an unusually diverse regulator of multiple steps in growth regulation because it also directly regulates c-myc transcription, mRNA export, splicing, and translation initiation.
Collapse
Affiliation(s)
- Mary Lynch
- Cancer Research Center at Massachusetts General Hospital and Harvard Medical School, 55 Fruit St., Boston, MA 02114, USA
| | | | | | | | | | | | | |
Collapse
|
44
|
Tolstonog GV, Li G, Shoeman RL, Traub P. Interaction in vitro of type III intermediate filament proteins with higher order structures of single-stranded DNA, particularly with G-quadruplex DNA. DNA Cell Biol 2005; 24:85-110. [PMID: 15699629 DOI: 10.1089/dna.2005.24.85] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Cytoplasmic intermediate filament (cIF) proteins interact strongly with single-stranded (ss) DNAs and RNAs, particularly with G-rich sequences. To test the hypothesis that this interaction depends on special nucleotide sequences and, possibly, higher order structures of ssDNA, a random mixture of mouse genomic ssDNA fragments generated by a novel "whole ssDNA genome PCR" technique via RNA intermediates was subjected to three rounds of affinity binding to in vitro reconstituted vimentin IFs at physiological ionic strength with intermediate PCR amplification of the bound ssDNA segments. Nucleotide sequence and computer folding analysis of the vimentin-selected fragments revealed an enrichment in microsatellites, predominantly of the (GT)n type, telomere DNA, and C/T-rich sequences, most of which, however, were incapable of folding into stable stem-loop structures. Because G-rich sequences were underrepresented in the vimentin-bound fraction, it had to be assumed that such sequences require intramolecular folding or lateral assembly into multistrand structures to be able to stably interact with vimentin, but that this requirement was inadequately fulfilled under the conditions of the selection experiment. For that reason, the few vimentin-selected G-rich ssDNA fragments and a number of telomere models were analyzed for their capacity to form inter- and intramolecular Gquadruplexes (G4 DNAs) under optimized conditions and to interact as such with vimentin and its type III relatives, glial fibrillary acidic protein, and desmin. Band shift assays indeed demonstrated differential binding of the cIF proteins to parallel four-stranded G4 DNAs and, with lower affinity, to bimolecular G'2 and unimolecular G'4 DNA configurations, whereby the transition regions from four- to single-strandedness played an additional role in the binding reaction. In this respect, the binding activity of cIF proteins was comparable with that toward other noncanonical DNA structures, like ds/ss DNA forks, triplex DNA, four-way junction DNA and Z-DNA, which also involve configurational transitions in their interaction with the filament proteins. Association of the cIF proteins with the corresponding nonfolded G-rich ssDNAs was negligible. Considering the almost universal involvement of ssDNA regions and G-quadruplexes in nuclear processes, including DNA transcription and recombination as well as telomere maintenance and dynamics, it is plausible to presume that cIF proteins as complementary constituents of the nuclear matrix participate in the cell- and tissue-specific regulation of these processes.
Collapse
|
45
|
Abstract
Since its original identification as a component of the heterogeneous nuclear ribonucleoprotein (hnRNP) complex, K protein has been found not only in the nucleus but also in the cytoplasm and mitochondria and is implicated in chromatin remodeling, transcription, splicing and translation processes. K protein contains multiple modules that, on one hand, bind kinases while, on the other hand, recruit chromatin, transcription, splicing and translation factors. Moreover, the K- protein-mediated interactions are regulated by signaling cascades. These observations are consistent with K protein acting as a docking platform to integrate signaling cascades by facilitating cross-talk between kinases and factors that mediate nucleic-acid-directed processes. Comparison of K across species reveals that it is an essential factor in metazoans, but not in yeast. Although some of the K protein interactions and functions are conserved in eukaryotes from yeast to man, the mammalian protein seems to play a wider role. The greater diversity of mammalian K protein interactions and function may reflect gain of novel docking sites and expansion evolutionary of gene expression networks.
Collapse
Affiliation(s)
- Karol Bomsztyk
- Department of Medicine, University of Washington, Seattle, WA 98195, USA.
| | | | | |
Collapse
|
46
|
Ostrowski J, Bomsztyk K. Nuclear shift of hnRNP K protein in neoplasms and other states of enhanced cell proliferation. Br J Cancer 2003; 89:1493-501. [PMID: 14562022 PMCID: PMC2394341 DOI: 10.1038/sj.bjc.6601250] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
The heterogeneous nuclear ribonucleoprotein K (hnRNP K), is a ubiquitously expressed protein that interacts with signal transducers, proteins that modulate gene expression and selective RNA and DNA motifs. K protein is modified in response to extracellular signals and directly regulates rates of transcription and translation. We used serum-treated hepatocyte culture, liver after partial hepatectomy and hepatic neoplasms as systems to compare expression, subcellular distribution and tyrosine phosphorylation of K protein in quiescent and dividing cells. The results show that expression of K protein mRNA was increased in states of enhanced proliferation. Levels of nuclear K protein were also higher in proliferating compared to resting cells. In contrast, levels of cytoplasmic K protein were the same or lower in dividing compared to quiescent cells. States of enhanced proliferation were also associated with increased levels of K protein tyrosine phosphorylation. Nuclear shift of K protein in dividing cells may reflect involvement of K protein in signalling multiple events that regulate expression of genes in proliferating cells.
Collapse
Affiliation(s)
- J Ostrowski
- Department of Gastroenterology, Medical Center for Postgraduate Education, Maria Sklodowska-Curie Memorial Cancer Center, ul. Roentgena 5, 02-781 Warsaw, Poland.
| | | |
Collapse
|