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Wang D, Hou L, Zhu N, Yang X, Zhou J, Cui Y, Guo J, Feng X, Liu J. Interaction of Nucleolin with the Fusion Protein of Avian Metapneumovirus Subgroup C Contributes to Viral Replication. Viruses 2022; 14:v14071402. [PMID: 35891383 PMCID: PMC9317408 DOI: 10.3390/v14071402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 06/23/2022] [Accepted: 06/24/2022] [Indexed: 12/02/2022] Open
Abstract
Avian metapneumovirus subgroup C (aMPV/C) is highly pathogenic to various avian species with acute respiratory tract clinicopathology and/or drops in egg production. Nucleolin (NCL), an important nucleolar protein, has been shown to regulate multiple viral replication and serve as a functional receptor for viral entry and internalization. Whether NCL is involved in aMPV/C pathogenesis is not known. In this study, we found that aMPV/C infection altered the subcellular localization of NCL in cultured cells. siRNA-targeted NCL resulted in a remarkable decline in aMPV/C replication in Vero cells. DF-1 cells showed a similar response after CRISPR/Cas9-mediated knock out of NCL during aMPV/C infection. Conversely, NCL overexpression significantly increased aMPV/C replication. Pretreatment with AS1411-a aptamer, a guanine (G)-rich oligonucleotide that forms four-stranded structures and competitively binding to NCL, decreased aMPV/C replication and viral titers in cultured cells. Additionally, we found that the aMPV/C fusion (F) protein specifically interacts with NCL through its central domain and that AS1411 disrupts this interaction, thus inhibiting viral replication. Taken together, these results reveal that the aMPV/C F protein interacts with NCL, which is employed by aMPV/C for efficient replication, thereby highlighting the strategic potential for control and therapy of aMPV/C infection.
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Affiliation(s)
- Dedong Wang
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Lei Hou
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Ning Zhu
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Xiaoyu Yang
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Jianwei Zhou
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Yongqiu Cui
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Jinshuo Guo
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Xufei Feng
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
| | - Jue Liu
- College of Veterimary Medicine, Yangzhou University, Yangzhou 225009, China; (D.W.); (L.H.); (N.Z.); (X.Y.); (J.Z.); (Y.C.); (J.G.); (X.F.)
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, Yangzhou 225009, China
- Correspondence:
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Mashreghi M, Azarpara H, Bazaz MR, Jafari A, Masoudifar A, Mirzaei H, Jaafari MR. Angiogenesis biomarkers and their targeting ligands as potential targets for tumor angiogenesis. J Cell Physiol 2017; 233:2949-2965. [DOI: 10.1002/jcp.26049] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 06/12/2017] [Indexed: 12/20/2022]
Affiliation(s)
- Mohammad Mashreghi
- NanotechnologyResearch Center; Mashhad University of Medical Sciences; Mashhad Iran
- School of Pharmacy; Mashhad University of Medical Sciences; Mashhad Iran
| | - Hassan Azarpara
- School of Medicine; Iran University of Medical Sciences; Tehran Iran
| | - Mahere R. Bazaz
- Division of Biotechnology, Faculty of Veterinary Medicine; Ferdowsi University of Mashhad; Mashhad Iran
| | - Arash Jafari
- School of Medicine; Birjand University of Medical Sciences; Birjand Iran
| | - Aria Masoudifar
- Department of Molecular Biotechnology, Cell Science Research Center; Royan Institute for Biotechnology; ACECR Isfahan Iran
| | - Hamed Mirzaei
- Department of Medical Biotechnology, School of Medicine; Mashhad University of Medical Sciences; Mashhad Iran
| | - Mahmoud R. Jaafari
- NanotechnologyResearch Center; Mashhad University of Medical Sciences; Mashhad Iran
- School of Pharmacy; Mashhad University of Medical Sciences; Mashhad Iran
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3
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Henrich SM, Usadel C, Werwein E, Burdova K, Janscak P, Ferrari S, Hess D, Klempnauer KH. Interplay with the Mre11-Rad50-Nbs1 complex and phosphorylation by GSK3β implicate human B-Myb in DNA-damage signaling. Sci Rep 2017; 7:41663. [PMID: 28128338 PMCID: PMC5269693 DOI: 10.1038/srep41663] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 12/21/2016] [Indexed: 12/30/2022] Open
Abstract
B-Myb, a highly conserved member of the Myb transcription factor family, is expressed ubiquitously in proliferating cells and controls the cell cycle dependent transcription of G2/M-phase genes. Deregulation of B-Myb has been implicated in oncogenesis and loss of genomic stability. We have identified B-Myb as a novel interaction partner of the Mre11-Rad50-Nbs1 (MRN) complex, a key player in the repair of DNA double strand breaks. We show that B-Myb directly interacts with the Nbs1 subunit of the MRN complex and is recruited transiently to DNA-damage sites. In response to DNA-damage B-Myb is phosphorylated by protein kinase GSK3β and released from the MRN complex. A B-Myb mutant that cannot be phosphorylated by GSK3β disturbs the regulation of pro-mitotic B-Myb target genes and leads to inappropriate mitotic entry in response to DNA-damage. Overall, our work suggests a novel function of B-Myb in the cellular DNA-damage signalling.
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Affiliation(s)
- Sarah Marie Henrich
- Institut for Biochemistry, Westfälische-Wilhelms-Universität, D-48149 Münster, Germany
- Graduate School of Chemistry (GSC-MS), Westfälische-Wilhelms-Universität, D-48149 Münster, Germany
| | - Clemens Usadel
- Institut for Biochemistry, Westfälische-Wilhelms-Universität, D-48149 Münster, Germany
| | - Eugen Werwein
- Institut for Biochemistry, Westfälische-Wilhelms-Universität, D-48149 Münster, Germany
| | - Kamila Burdova
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 143 00 Prague, Czech Republic
| | - Pavel Janscak
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, 143 00 Prague, Czech Republic
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstr.190, CH-8057 Zürich, Switzerland
| | - Stefano Ferrari
- Institute of Molecular Cancer Research, University of Zurich, Winterthurerstr.190, CH-8057 Zürich, Switzerland
| | - Daniel Hess
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstr. 66, CH-4058 Basel, Switzerland
| | - Karl-Heinz Klempnauer
- Institut for Biochemistry, Westfälische-Wilhelms-Universität, D-48149 Münster, Germany
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Interactomic analysis of REST/NRSF and implications of its functional links with the transcription suppressor TRIM28 during neuronal differentiation. Sci Rep 2016; 6:39049. [PMID: 27976729 PMCID: PMC5157023 DOI: 10.1038/srep39049] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Accepted: 11/17/2016] [Indexed: 01/06/2023] Open
Abstract
RE-1 silencing transcription factor (REST) is a transcriptional repressor that regulates gene expression by binding to repressor element 1. However, despite its critical function in physiology, little is known about its interaction proteins. Here we identified 204 REST-interacting proteins using affinity purification and mass spectrometry. The interactome included proteins associated with mRNA processing/splicing, chromatin organization, and transcription. The interactions of these REST-interacting proteins, which included TRIM28, were confirmed by co-immunoprecipitation and immunocytochemistry, respectively. Gene Ontology (GO) analysis revealed that neuronal differentiation-related GO terms were enriched among target genes that were co-regulated by REST and TRIM28, while the level of CTNND2 was increased by the knockdown of REST and TRIM28. Consistently, the level of CTNND2 increased while those of REST and TRIM28 decreased during neuronal differentiation in the primary neurons, suggesting that CTNND2 expression may be co-regulated by both. Furthermore, neurite outgrowth was increased by depletion of REST or TRIM28, implying that reduction of both REST and TRIM28 could promote neuronal differentiation via induction of CTNND2 expression. In conclusion, our study of REST reveals novel interacting proteins which could be a valuable resource for investigating unidentified functions of REST and also suggested functional links between REST and TRIM28 during neuronal development.
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5
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Recent advances in the understanding of the Aspergillus fumigatus cell wall. J Microbiol 2016; 54:232-42. [PMID: 26920883 DOI: 10.1007/s12275-016-6045-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 02/02/2016] [Indexed: 10/24/2022]
Abstract
Over the past several decades, research on the synthesis and organization of the cell wall polysaccharides of Aspergillus fumigatus has expanded our knowledge of this important fungal structure. Besides protecting the fungus from environmental stresses and maintaining structural integrity of the organism, the cell wall is also the primary site for interaction with host tissues during infection. Cell wall polysaccharides are important ligands for the recognition of fungi by the innate immune system and they can mediate potent immunomodulatory effects. The synthesis of cell wall polysaccharides is a complicated process that requires coordinated regulation of many biosynthetic and metabolic pathways. Continuous synthesis and remodeling of the polysaccharides of the cell wall is essential for the survival of the fungus during development, reproduction, colonization and invasion. As these polysaccharides are absent from the human host, these biosynthetic pathways are attractive targets for antifungal development. In this review, we present recent advances in our understanding of Aspergillus fumigatus cell wall polysaccharides, including the emerging role of cell wall polysaccharides in the host-pathogen interaction.
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Xiao S, Caglar E, Maldonado P, Das D, Nadeem Z, Chi A, Trinité B, Li X, Saxena A. Induced expression of nucleolin phosphorylation-deficient mutant confers dominant-negative effect on cell proliferation. PLoS One 2014; 9:e109858. [PMID: 25313645 PMCID: PMC4196967 DOI: 10.1371/journal.pone.0109858] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2014] [Accepted: 09/08/2014] [Indexed: 11/25/2022] Open
Abstract
Nucleolin (NCL) is a major nucleolar phosphoprotein that has pleiotropic effects on cell proliferation and is elevated in a variety of tumors. NCL is highly phosphorylated at the N-terminus by two major kinases: interphase casein kinase 2 (CK2) and mitotic cyclin-dependent kinase 1 (CDK1). Earlier we demonstrated that a NCL-mutant that is partly defective in undergoing phosphorylation by CK2 inhibits chromosomal replication through its interactions with Replication Protein A, mimicking the cellular response to DNA damage. We further delineated that the N-terminus of NCL associates with Hdm2, the most common E3 ubiquitin ligase of p53. We reported that NCL antagonizes Hdm2 to stabilize p53 and stimulates p53 transcriptional activity. Although NCL-phosphorylation by CK2 and ribosomal DNA transcription are closely coordinated during interphase, the role of NCL phosphorylation in regulating cell proliferation remains unexplored. We have therefore engineered unique human cells that specifically induce expression of NCL-wild type (WT) or a phosphorylation-deficient NCL-mutant, 6/S*A where all the six CK2 consensus serine sites residing in the N-terminus NCL were mutated to alanine. Here we show that this NCL-mutant is defective in undergoing phosphorylation by CK2. We also demonstrate that NCL-phosphorylation by CK2 is required through the S-phase progression in cell cycle and hence proliferation. Induced expression of NCL with mutated CK2 phosphorylation sites stabilizes p53, results in higher expression of Bcl2 (B-cell lymphoma 2) homology 3 (BH3)-only apoptotic markers and causes a dominant-negative effect on cell viability. Our unique cellular system thus provides the first evidential support to delineate phospho-specific functions of NCL on cell proliferation.
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Affiliation(s)
- Shu Xiao
- Biology Department, Brooklyn College, Brooklyn, New York, United States of America
- City University of New York, Graduate Center, New York, New York, United States of America
| | - Elif Caglar
- Biology Department, Brooklyn College, Brooklyn, New York, United States of America
| | - Priscilla Maldonado
- New York University School of Medicine, New York, New York, United States of America
| | - Dibash Das
- Biology Department, Brooklyn College, Brooklyn, New York, United States of America
- City University of New York, Graduate Center, New York, New York, United States of America
| | - Zaineb Nadeem
- Biology Department, Brooklyn College, Brooklyn, New York, United States of America
| | - Angela Chi
- Great Neck South High School, Great Neck, New York, United States of America
| | - Benjamin Trinité
- New York University College of Dentistry, New York, New York, United States of America
| | - Xin Li
- New York University College of Dentistry, New York, New York, United States of America
| | - Anjana Saxena
- Biology Department, Brooklyn College, Brooklyn, New York, United States of America
- City University of New York, Graduate Center, New York, New York, United States of America
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7
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Downregulation of rRNA transcription triggers cell differentiation. PLoS One 2014; 9:e98586. [PMID: 24879416 PMCID: PMC4039485 DOI: 10.1371/journal.pone.0098586] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Accepted: 05/05/2014] [Indexed: 11/19/2022] Open
Abstract
Responding to various stimuli is indispensable for the maintenance of homeostasis. The downregulation of ribosomal RNA (rRNA) transcription is one of the mechanisms involved in the response to stimuli by various cellular processes, such as cell cycle arrest and apoptosis. Cell differentiation is caused by intra- and extracellular stimuli and is associated with the downregulation of rRNA transcription as well as reduced cell growth. The downregulation of rRNA transcription during differentiation is considered to contribute to reduced cell growth. However, the downregulation of rRNA transcription can induce various cellular processes; therefore, it may positively regulate cell differentiation. To test this possibility, we specifically downregulated rRNA transcription using actinomycin D or a siRNA for Pol I-specific transcription factor IA (TIF-IA) in HL-60 and THP-1 cells, both of which have differentiation potential. The inhibition of rRNA transcription induced cell differentiation in both cell lines, which was demonstrated by the expression of the common differentiation marker CD11b. Furthermore, TIF-IA knockdown in an ex vivo culture of mouse hematopoietic stem cells increased the percentage of myeloid cells and reduced the percentage of immature cells. We also evaluated whether differentiation was induced via the inhibition of cell cycle progression because rRNA transcription is tightly coupled to cell growth. We found that cell cycle arrest without affecting rRNA transcription did not induce differentiation. To the best of our knowledge, our results demonstrate the first time that the downregulation of rRNA levels could be a trigger for the induction of differentiation in mammalian cells. Furthermore, this phenomenon was not simply a reflection of cell cycle arrest. Our results provide a novel insight into the relationship between rRNA transcription and cell differentiation.
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8
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Chen YL, Liu CD, Cheng CP, Zhao B, Hsu HJ, Shen CL, Chiu SJ, Kieff E, Peng CW. Nucleolin is important for Epstein-Barr virus nuclear antigen 1-mediated episome binding, maintenance, and transcription. Proc Natl Acad Sci U S A 2014; 111:243-8. [PMID: 24344309 PMCID: PMC3890893 DOI: 10.1073/pnas.1321800111] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA1) is essential for EBV episome maintenance, replication, and transcription. These effects are mediated by EBNA1 binding to cognate oriP DNA, which comprise 20 imperfect copies of a 30-bp dyad symmetry enhancer and an origin for DNA replication. To identify cell proteins essential for these EBNA1 functions, EBNA1 associated cell proteins were immune precipitated and analyzed by liquid chromatography-tandem mass spectrometry. Nucleolin (NCL) was identified to be EBNA1 associated. EBNA1's N-terminal 100 aa and NCL's RNA-binding domains were critical for EBNA1/NCL interaction. Lentivirus shRNA-mediated NCL depletion substantially reduced EBNA1 recruitment to oriP DNA, EBNA1-dependent transcription of an EBV oriP luciferase reporter, and EBV genome maintenance in lymphoblastoid cell lines. NCL RNA-binding domain K429 was critical for ATP and EBNA1 binding. NCL overexpression increased EBNA1 binding to oriP and transcription, whereas NCL K429A was deficient. Moreover, NCL silencing impaired lymphoblastoid cell line growth. These experiments reveal a surprisingly critical role for NCL K429 in EBNA1 episome maintenance and transcription, which may be a target for therapeutic intervention.
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Affiliation(s)
- Ya-Lin Chen
- Department of Life Sciences, Tzu-Chi University, Hualien 97004, Taiwan; and
| | - Cheng-Der Liu
- Department of Life Sciences, Tzu-Chi University, Hualien 97004, Taiwan; and
| | - Chi-Ping Cheng
- Department of Life Sciences, Tzu-Chi University, Hualien 97004, Taiwan; and
| | - Bo Zhao
- Department of Medicine, Brigham and Women’s Hospital, and Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115
| | - Hao-Jen Hsu
- Department of Life Sciences, Tzu-Chi University, Hualien 97004, Taiwan; and
| | - Chih-Long Shen
- Department of Life Sciences, Tzu-Chi University, Hualien 97004, Taiwan; and
| | - Shu-Jun Chiu
- Department of Life Sciences, Tzu-Chi University, Hualien 97004, Taiwan; and
| | - Elliott Kieff
- Department of Medicine, Brigham and Women’s Hospital, and Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA 02115
| | - Chih-wen Peng
- Department of Life Sciences, Tzu-Chi University, Hualien 97004, Taiwan; and
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Kasper LH, Fukuyama T, Lerach S, Chang Y, Xu W, Wu S, Boyd KL, Brindle PK. Genetic interaction between mutations in c-Myb and the KIX domains of CBP and p300 affects multiple blood cell lineages and influences both gene activation and repression. PLoS One 2013; 8:e82684. [PMID: 24340053 PMCID: PMC3858336 DOI: 10.1371/journal.pone.0082684] [Citation(s) in RCA: 23] [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: 07/02/2013] [Accepted: 10/28/2013] [Indexed: 02/06/2023] Open
Abstract
Adult blood cell production or definitive hematopoiesis requires the transcription factor c-Myb. The closely related KAT3 histone acetyltransferases CBP (CREBBP) and p300 (EP300) bind c-Myb through their KIX domains and mice homozygous for a p300 KIX domain mutation exhibit multiple blood defects. Perplexingly, mice homozygous for the same KIX domain mutation in CBP have normal blood. Here we test the hypothesis that the CBP KIX domain contributes subordinately to hematopoiesis via a genetic interaction with c-Myb. We assessed hematopoiesis in mice bearing compound mutations of c-Myb and/or the KIX domains of CBP and p300, and measured the effect of KIX domain mutations on c-Myb-dependent gene expression. We found that in the context of a p300 KIX mutation, the CBP KIX domain mutation affects platelets, B cells, T cells, and red cells. Gene interaction (epistasis) analysis provides mechanistic evidence that blood defects in KIX mutant mice are consistent with reduced c-Myb and KIX interaction. Lastly, we demonstrated that the CBP and p300 KIX domains contribute to both c-Myb-dependent gene activation and repression. Together these results suggest that the KIX domains of CBP, and especially p300, are principal mediators of c-Myb-dependent gene activation and repression that is required for definitive hematopoiesis.
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Affiliation(s)
- Lawryn H. Kasper
- Department of Biochemistry, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Tomofusa Fukuyama
- Department of Biochemistry, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Stephanie Lerach
- Department of Biochemistry, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Yunchao Chang
- Department of Biochemistry, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Wu Xu
- Department of Biochemistry, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Song Wu
- Department of Biostatistics, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Kelli L. Boyd
- Veterinary Pathology Core, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Paul K. Brindle
- Department of Biochemistry, St. Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
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Werwein E, Dzuganova M, Usadel C, Klempnauer KH. B-Myb switches from Cyclin/Cdk-dependent to Jnk- and p38 kinase-dependent phosphorylation and associates with SC35 bodies after UV stress. Cell Death Dis 2013; 4:e511. [PMID: 23449447 PMCID: PMC3734824 DOI: 10.1038/cddis.2013.36] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
B-Myb is a highly conserved member of the Myb transcription factor family that has essential roles in cell-cycle progression. Recent work has suggested that B-Myb is also involved in the cellular DNA-damage response. Here, we have investigated the fate of B-Myb in UV-irradiated cells. UV stress leads to the appearance of phosphorylated B-Myb in nuclear SC35 speckles during transcriptional shutdown. Furthermore, we show that UV irradiation leads to a change of the phosphorylation pattern of B-Myb, which is caused by a switch from Cyclin/Cdk-dependent to Jnk and p38 kinase-dependent phosphorylation. Taken together, we have identified Jnk and p38 kinase as novel regulators of B-Myb and established the localization of phosphorylated B-Myb in SC35 speckles as a potential novel regulatory mechanism for B-Myb in UV irradiated cells.
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Affiliation(s)
- E Werwein
- Institut für Biochemie, Wilhelm-Klemm-Straße 2, D-48149 Münster, Germany
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11
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Werwein E, Schmedt T, Hoffmann H, Usadel C, Obermann N, Singer JD, Klempnauer KH. B-Myb promotes S-phase independently of its sequence-specific DNA binding activity and interacts with polymerase delta-interacting protein 1 (Pdip1). Cell Cycle 2012; 11:4047-58. [PMID: 23032261 DOI: 10.4161/cc.22386] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
B-Myb is a highly conserved member of the Myb transcription factor family, which plays an essential role in cell cycle progression by regulating the transcription of genes at the G 2/M-phase boundary. The role of B-Myb in other parts of the cell cycle is less well-understood. By employing siRNA-mediated silencing of B-Myb expression, we found that B-Myb is required for efficient entry into S-phase. Surprisingly, a B-Myb mutant that lacks sequence-specific DNA-binding activity and is unable to activate transcription of B-Myb target genes is able to rescue the S-phase defect observed after B-Myb knockdown. Moreover, we have identified polymerase delta-interacting protein 1 (Pdip1), a BTB domain protein known to bind to the DNA replication and repair factor PCNA as a novel B-Myb interaction partner. We have shown that Pdip1 is able to interact with B-Myb and PCNA simultaneously. In addition, we found that a fraction of endogenous B-Myb can be co-precipitated via PCNA, suggesting that B-Myb might be involved in processes related to DNA replication or repair. Taken together, our work suggests a novel role for B-Myb in S-phase that appears to be independent of its sequence-specific DNA-binding activity and its ability to stimulate the expression of bona fide B-Myb target genes.
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Affiliation(s)
- Eugen Werwein
- Institut für Biochemie, Westfälische-Wilhelms-Universität Münster, Münster, Germany
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12
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Litchfield LM, Riggs KA, Hockenberry AM, Oliver LD, Barnhart KG, Cai J, Pierce WM, Ivanova MM, Bates PJ, Appana SN, Datta S, Kulesza P, McBryan J, Young LS, Klinge CM. Identification and characterization of nucleolin as a COUP-TFII coactivator of retinoic acid receptor β transcription in breast cancer cells. PLoS One 2012; 7:e38278. [PMID: 22693611 PMCID: PMC3365040 DOI: 10.1371/journal.pone.0038278] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 05/02/2012] [Indexed: 01/12/2023] Open
Abstract
INTRODUCTION The orphan nuclear receptor COUP-TFII plays an undefined role in breast cancer. Previously we reported lower COUP-TFII expression in tamoxifen/endocrine-resistant versus sensitive breast cancer cell lines. The identification of COUP-TFII-interacting proteins will help to elucidate its mechanism of action as a transcriptional regulator in breast cancer. RESULTS FLAG-affinity purification and multidimensional protein identification technology (MudPIT) identified nucleolin among the proteins interacting with COUP-TFII in MCF-7 tamoxifen-sensitive breast cancer cells. Interaction of COUP-TFII and nucleolin was confirmed by coimmunoprecipitation of endogenous proteins in MCF-7 and T47D breast cancer cells. In vitro studies revealed that COUP-TFII interacts with the C-terminal arginine-glycine repeat (RGG) domain of nucleolin. Functional interaction between COUP-TFII and nucleolin was indicated by studies showing that siRNA knockdown of nucleolin and an oligonucleotide aptamer that targets nucleolin, AS1411, inhibited endogenous COUP-TFII-stimulated RARB2 expression in MCF-7 and T47D cells. Chromatin immunoprecipitation revealed COUP-TFII occupancy of the RARB2 promoter was increased by all-trans retinoic acid (atRA). RARβ2 regulated gene RRIG1 was increased by atRA and COUP-TFII transfection and inhibited by siCOUP-TFII. Immunohistochemical staining of breast tumor microarrays showed nuclear COUP-TFII and nucleolin staining was correlated in invasive ductal carcinomas. COUP-TFII staining correlated with ERα, SRC-1, AIB1, Pea3, MMP2, and phospho-Src and was reduced with increased tumor grade. CONCLUSIONS Our data indicate that nucleolin plays a coregulatory role in transcriptional regulation of the tumor suppressor RARB2 by COUP-TFII.
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Affiliation(s)
- Lacey M. Litchfield
- Department of Biochemistry & Molecular Biology and Center for Genetics and Molecular Medicine, Louisville, Kentucky, United States of America
| | - Krista A. Riggs
- Department of Biochemistry & Molecular Biology and Center for Genetics and Molecular Medicine, Louisville, Kentucky, United States of America
| | - Alyson M. Hockenberry
- Department of Biochemistry & Molecular Biology and Center for Genetics and Molecular Medicine, Louisville, Kentucky, United States of America
| | - Laura D. Oliver
- Department of Biochemistry & Molecular Biology and Center for Genetics and Molecular Medicine, Louisville, Kentucky, United States of America
| | - Katelyn G. Barnhart
- Department of Biochemistry & Molecular Biology and Center for Genetics and Molecular Medicine, Louisville, Kentucky, United States of America
| | - Jian Cai
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - William M. Pierce
- Department of Pharmacology and Toxicology, University of Louisville School of Medicine, Louisville, Kentucky, United States of America
| | - Margarita M. Ivanova
- Department of Biochemistry & Molecular Biology and Center for Genetics and Molecular Medicine, Louisville, Kentucky, United States of America
| | - Paula J. Bates
- James Graham Brown Cancer Center, Louisville, Kentucky, United States of America
| | - Savitri N. Appana
- Department of Bioinformatics and Biostatistics, University of Louisville School of Public Health and Information Sciences, Louisville, Kentucky, United States of America
| | - Susmita Datta
- Department of Bioinformatics and Biostatistics, University of Louisville School of Public Health and Information Sciences, Louisville, Kentucky, United States of America
| | - Piotr Kulesza
- Department of Pathology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Jean McBryan
- Endocrine Oncology Research Group, Department of Surgery, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Leonie S. Young
- Endocrine Oncology Research Group, Department of Surgery, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Carolyn M. Klinge
- Department of Biochemistry & Molecular Biology and Center for Genetics and Molecular Medicine, Louisville, Kentucky, United States of America
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13
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Jerke U, Tkachuk S, Kiyan J, Stepanova V, Kusch A, Hinz M, Dietz R, Haller H, Fuhrman B, Dumler I. Stat1 nuclear translocation by nucleolin upon monocyte differentiation. PLoS One 2009; 4:e8302. [PMID: 20011528 PMCID: PMC2788426 DOI: 10.1371/journal.pone.0008302] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2009] [Accepted: 11/19/2009] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Members of the signal transducer and activator of transcription (Stat) family of transcription factors traverse the nuclear membrane through a specialized structure, called the nuclear pore complex (NPC), which represents a selective filter for the import of proteins. Karyophilic molecules can bind directly to a subset of proteins of the NPC, collectively called nucleoporins. Alternatively, the transport is mediated via a carrier molecule belonging to the importin/karyopherin superfamily, which transmits the import into the nucleus through the NPC. METHODOLOGY/PRINCIPAL FINDINGS In this study, we provide evidence for an alternative Stat1 nuclear import mechanism, which is mediated by the shuttle protein nucleolin. We observed Stat1-nucleolin association, nuclear translocation and specific binding to the regulatory DNA element GAS. Using expression of nucleolin transgenes, we found that the nuclear localization signal (NLS) of nucleolin is responsible for Stat1 nuclear translocation. We show that this mechanism is utilized upon differentiation of myeloid cells and is specific for the differentiation step from monocytes to macrophages. CONCLUSIONS/SIGNIFICANCE Our data add the nucleolin-Stat1 complex as a novel functional partner for the cell differentiation program, which is uniquely poised to regulate the transcription machinery via Stat1 and nuclear metabolism via nucleolin.
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Affiliation(s)
- Uwe Jerke
- Hannover Medical School, Hannover, Germany.
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14
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Sieff CA, Yang J, Merida-Long LB, Lodish HF. Pathogenesis of the erythroid failure in Diamond Blackfan anaemia. Br J Haematol 2009; 148:611-22. [PMID: 19958353 DOI: 10.1111/j.1365-2141.2009.07993.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Diamond Blackfan anaemia (DBA) is a severe congenital failure of erythropoiesis. Despite mutations in one of several ribosome protein genes, including RPS19, the cause of the erythroid specificity is still a mystery. We hypothesized that, because the chromatin of late erythroid cells becomes condensed and transcriptionally inactive prior to enucleation, the rapidly proliferating immature cells require very high ribosome synthetic rates. RNA biogenesis was measured in primary mouse fetal liver erythroid progenitor cells; during the first 24 h, cell number increased three to fourfold while, remarkably, RNA content increased sixfold, suggesting an accumulation of an excess of ribosomes during early erythropoiesis. Retrovirus infected siRNA RPS19 knockdown cells showed reduced proliferation but normal differentiation, and cell cycle analysis showed a G1/S phase delay. p53 protein was increased in the knockdown cells, and the mRNA level for p21, a transcriptional target of p53, was increased. Furthermore, we show that RPS19 knockdown decreased MYB protein, and Kit mRNA was reduced, as was the amount of cell surface KIT protein. Thus, in this small hairpin RNA murine model of DBA, RPS19 insufficient erythroid cells may proliferate poorly because of p53-mediated cell cycle arrest, and also because of decreased expression of the key erythroid signalling protein KIT.
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Affiliation(s)
- Colin A Sieff
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.
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15
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Sato H, Kusumoto-Matsuo R, Ishii Y, Mori S, Nakahara T, Shinkai-Ouchi F, Kawana K, Fujii T, Taketani Y, Kanda T, Kukimoto I. Identification of nucleolin as a protein that binds to human papillomavirus type 16 DNA. Biochem Biophys Res Commun 2009; 387:525-30. [PMID: 19615975 DOI: 10.1016/j.bbrc.2009.07.055] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2009] [Accepted: 07/13/2009] [Indexed: 12/12/2022]
Abstract
Transcription, replication, and segregation of human papillomaviruses (HPVs) are regulated by various host factors, but our understanding of host proteins that bind to the HPV genome is limited. Here we report the results of a search of cellular proteins that can associate with specific genomic regions of HPV type 16 (HPV16). We found that human nucleolin, an abundant nucleolar protein, was preferentially captured in vitro by an HPV16 genomic fragment from nucleotide positions (nt) 531-780. Electrophoretic mobility shift assays with a bacterially expressed nucleolin revealed that nucleolin bound to an HPV16 genomic region between nt 604 and 614 in a sequence-dependent manner. Chromatin immunoprecipitation analysis showed that both exogenous and endogenous nucleolin bound to a plasmid containing the HPV16 genomic region in HeLa cells. Furthermore, nucleolin associated with the HPV16 genome stably maintained in HPV16-infected W12 cells, suggesting that the nucleolin binding may be involved in the dynamics of the HPV genome in cells.
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Affiliation(s)
- Hidetaka Sato
- Pathogen Genomics Center, National Institute of Infectious Diseases, 1-23-1 Toyama, Shinjuku-ku, Tokyo, Japan
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16
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Yang C, Kim MS, Chakravarty D, Indig FE, Carrier F. Nucleolin Binds to the Proliferating Cell Nuclear Antigen and Inhibits Nucleotide Excision Repair. ACTA ACUST UNITED AC 2009; 1:130-137. [PMID: 20336191 DOI: 10.4255/mcpharmacol.09.17] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Nucleolin is over-expressed in malignant tumors and is used as a marker for cell proliferation and to reliably predict tumor growth rate. However, it is not known whether nucleolin expression is directly involved in or is a consequence of carcinogenesis. Using GST-pull down assays, we have determined that the recombinant nucleolin interacts with the Proliferating Cell Nuclear Antigen (PCNA). Co-immunoprecipitation assays indicate that the nucleolin-PCNA interaction also occurs in intact cells and this interaction increases after exposure of colon carcinoma RKO cells to UV radiation. Moreover, our data indicate that PCNA and nucleolin co-localize in some areas within the RKO cell nuclei. The functional significance of this interaction is evaluated on Nucleotide Excision Repair (NER) since PCNA is a primary mediator of this cellular function. Our data indicate that overexpression of nucleolin decreases the repair efficiency of UV damaged plasmid DNA in RKO cells. Co-transfection with PCNA can rescue this effect in vivo. Furthermore, reduction of nucleolin protein levels increases DNA repair efficiency in RKO and CHO cells and consequently increases cell survival. These data indicate that the direct interaction of nucleolin with PCNA inhibits NER efficiency of UV damaged DNA. This effect could contribute to carcinogenesis and aging in cells over-expressing nucleolin.
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Affiliation(s)
- Chonglin Yang
- Marlene and Stewart Greenebaum Cancer Center and Department of Radiation Oncology, University of Maryland at Baltimore School of Medicine, Baltimore, Maryland
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17
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18
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Johnson JS, Samulski RJ. Enhancement of adeno-associated virus infection by mobilizing capsids into and out of the nucleolus. J Virol 2009; 83:2632-44. [PMID: 19109385 PMCID: PMC2648275 DOI: 10.1128/jvi.02309-08] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2008] [Accepted: 12/18/2008] [Indexed: 11/20/2022] Open
Abstract
Adeno-associated virus (AAV) serotypes are being tailored for numerous therapeutic applications, but the parameters governing the subcellular fate of even the most highly characterized serotype, AAV2, remain unclear. To understand how cellular conditions control capsid trafficking, we have tracked the subcellular fate of recombinant AAV2 (rAAV2) vectors using confocal immunofluorescence, three-dimensional infection analysis, and subcellular fractionation. Here we report that a population of rAAV2 virions enters the nucleus and accumulates in the nucleolus after infection, whereas empty capsids are excluded from nuclear entry. Remarkably, after subcellular fractionation, virions accumulating in nucleoli were found to retain infectivity in secondary infections. Proteasome inhibitors known to enhance transduction were found to potentiate nucleolar accumulation. In contrast, hydroxyurea, which also increases transduction, mobilized virions into the nucleoplasm, suggesting that two separate pathways influence vector delivery in the nucleus. Using a small interfering RNA (siRNA) approach, we then evaluated whether nucleolar proteins B23/nucleophosmin and nucleolin, previously shown to interact with AAV2 capsids, affect trafficking and transduction efficiency. Similar to effects observed with proteasome inhibition, siRNA-mediated knockdown of nucleophosmin potentiated nucleolar accumulation and increased transduction 5- to 15-fold. Parallel to effects from hydroxyurea, knockdown of nucleolin mobilized capsids to the nucleoplasm and increased transduction 10- to 30-fold. Moreover, affecting both pathways simultaneously using drug and siRNA combinations was synergistic and increased transduction over 50-fold. Taken together, these results support the hypothesis that rAAV2 virions enter the nucleus intact and can be sequestered in the nucleolus in stable form. Mobilization from the nucleolus to nucleoplasmic sites likely permits uncoating and subsequent gene expression or genome degradation. In summary, with these studies we have refined our understanding of AAV2 trafficking dynamics and have identified cellular parameters that mobilize virions in the nucleus and significantly influence AAV infection.
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Affiliation(s)
- Jarrod S Johnson
- Gene Therapy Center and Department of Pharmacology, The University of North Carolina at Chapel Hill, 7119 Thurston Bowles, CB 7352, Chapel Hill, North Carolina 27599-7352, USA
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19
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Losfeld ME, Khoury DE, Mariot P, Carpentier M, Krust B, Briand JP, Mazurier J, Hovanessian AG, Legrand D. The cell surface expressed nucleolin is a glycoprotein that triggers calcium entry into mammalian cells. Exp Cell Res 2009; 315:357-69. [PMID: 19026635 DOI: 10.1016/j.yexcr.2008.10.039] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 10/16/2008] [Accepted: 10/23/2008] [Indexed: 11/24/2022]
Abstract
Nucleolin is an ubiquitous nucleolar phosphoprotein involved in fundamental aspects of transcription regulation, cell proliferation and growth. It has also been described as a shuttling molecule between nucleus, cytosol and the cell surface. Several studies have demonstrated that surface nucleolin serves as a receptor for various extracellular ligands implicated in cell proliferation, differentiation, adhesion, mitogenesis and angiogenesis. Previously, we reported that nucleolin in the extranuclear cell compartment is a glycoprotein containing N- and O-glycans. In the present study, we show that glycosylation is an essential requirement for surface nucleolin expression, since it is prevented when cells are cultured in the presence of tunicamycin, an inhibitor of N-glycosylation. Accordingly, surface but not nuclear nucleolin is radioactively labeled upon metabolic labeling of cells with [(3)H]glucosamine. Besides its well-demonstrated role in the internalization of specific ligands, here we show that ligand binding to surface nucleolin could also induce Ca(2+) entry into cells. Indeed, by flow cytometry, microscopy and patch-clamp experiments, we show that the HB-19 pseudopeptide, which binds specifically surface nucleolin, triggers rapid and intense membrane Ca(2+) fluxes in various types of cells. The use of several drugs then indicated that Store-Operated Ca(2+) Entry (SOCE)-like channels are involved in the generation of these fluxes. Taken together, our findings suggest that binding of an extracellular ligand to surface nucleolin could be involved in the activation of signaling pathways by promoting Ca(2+) entry into cells.
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Affiliation(s)
- Marie-Estelle Losfeld
- Unité de Glycobiologie Structurale et Fonctionnelle, Unité Mixte de Recherche no 8576 du Centre National de la Recherche Scientifique, France
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20
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Nawarak J, Huang-Liu R, Kao SH, Liao HH, Sinchaikul S, Chen ST, Cheng SL. Proteomics analysis of kojic acid treated A375 human malignant melanoma cells. J Proteome Res 2008; 7:3737-46. [PMID: 18630942 DOI: 10.1021/pr7008737] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Although the toxicogenomics of kojic acid treated A375 human malignant melanoma cells has been elucidated, the proteomics of cellular response is still poorly understood. We performed proteomic analysis to investigate the anticancer effect of kojic acid on protein expression profile in A375 cells. A375 cells were treated with kojic acid at 8 microg/mL for 24, 48, and 72 h. With the use of 2-D PAGE and MALDI-Q-TOF MS and MS/MS analyses, proteomic profiles of A375 cells between control and kojic acid treatment were compared, and 30 differentially expressed proteins, containing 2 up-regulated proteins and 28 down-regulated proteins, were identified. Among these proteins, 17 isoforms of 5 identical proteins were observed and 11 chaperone proteins showed the high proportion of protein spots with 36.7% of total proteins. Bioinformatic tools were used to search for protein function and prediction of protein interaction. Sixteen differentially expressed proteins exhibited interaction network linked to the downstream regulations of p53 tumor suppressor and cell apoptosis, which may lead to suppress the melanogenesis and tumorigenesis of kojic acid treated A375 cells. In addition, GRP75, VIME and 2AAA were validated by Western blot analysis, whereas GRP75, 2AAA, HS90B, ENPL and KPYM were validated by RT-PCR. Therefore, these proteins play the important roles in cancer progression and may be potential biomarkers that are useful for diagnostic and therapeutic applications of malignant melanoma cancer.
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Affiliation(s)
- Jiraporn Nawarak
- Institute of Biological Chemistry and Genomics Research Center, Academia Sinica, Taipei, Taiwan
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21
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Nucleolin – Characteristics of Protein and its Role in Biology of Cancers and Viral Infections. ACTA ACUST UNITED AC 2008. [DOI: 10.2478/v10052-008-0003-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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22
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Yamauchi T, Keough RA, Gonda TJ, Ishii S. Ribosomal stress induces processing of Mybbp1a and its translocation from the nucleolus to the nucleoplasm. Genes Cells 2008; 13:27-39. [PMID: 18173745 DOI: 10.1111/j.1365-2443.2007.01148.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Myb-binding protein 1a (Mybbp1a) was originally identified as a c-myb proto-oncogene product (c-Myb)-interacting protein, and also binds to various other transcription factors. The 160-kDa Mybbp1a protein (p160(MBP)) is ubiquitously expressed and is post-translationally processed in some types of cells to generate an amino-terminal 67 kDa fragment (p67(MBP)). Despite its interaction with various transcription factors, Mybbp1a is localized predominantly, but not exclusively, in nucleoli. Here, we have purified the two Mybbp1a-containing complexes. The smaller complex contained p67(MBP) and p140(MBP), which lacked the C-terminal region of p160(MBP) containing the nucleolar localization sequences. The larger complex contained the intact p160(MBP) and various ribosomal subunits. Treatment of cells with actinomycin D (ActD), cisplatin or UV, all of which inhibit ribosome biogenesis, induced processing of p160(MBP) into p140(MBP) and p67(MBP). ActD, cisplatin and UV also induced a translocation of Mybbp1a from the nucleolus to the nucleoplasm. Both small and large Mybbp1a complexes contained nucleophosmin and nucleolin. In contrast, nucleostemin was detected only in the large complex, while the cell cycle-regulated protein EBP1 was only in the small complex. These results suggest that Mybbp1a may connect the ribosome biogenesis and the Myb-dependent transcription, which controls cell cycle progression and proliferation.
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Affiliation(s)
- Tomohiro Yamauchi
- Laboratory of Molecular Genetics, RIKEN Tsukuba Institute, 3-1-1 Koyadai, Tsukuba, Ibaraki 305-0074, Japan
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23
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Tsou JH, Chang KY, Wang WC, Tseng JT, Su WC, Hung LY, Chang WC, Chen BK. Nucleolin regulates c-Jun/Sp1-dependent transcriptional activation of cPLA2alpha in phorbol ester-treated non-small cell lung cancer A549 cells. Nucleic Acids Res 2008; 36:217-27. [PMID: 18025046 PMCID: PMC2248756 DOI: 10.1093/nar/gkm1027] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2007] [Revised: 10/16/2007] [Accepted: 10/29/2007] [Indexed: 01/01/2023] Open
Abstract
The expression of cPLA2 is critical for transformed growth of non-small cell lung cancer (NSCLC). It is known that phorbol 12-myristate 13-acetate (PMA)-activated signal transduction pathway is thought to be involved in the oncogene action in NSCLC and enzymatic activation of cPLA2. However, the transcriptional regulation of cPLA2alpha in PMA-activated NSCLC is not clear. In this study, we found that PMA induced the mRNA level and protein expression of cPLA2alpha. In addition, two Sp1-binding sites of cPLA2alpha promoter were required for response to PMA and c-Jun overexpression. Small interfering RNA (siRNA) of c-Jun and nucleolin inhibited PMA induced the promoter activity and protein expression of cPLA2alpha. Furthermore, PMA stimulated the formation of c-Jun/Sp1 and c-Jun/nucleolin complexes as well as the binding of these transcription factor complexes to the cPLA2alpha promoter. Although Sp1-binding sites were required for the bindings of Sp1 and nucleolin to the promoter, the binding of nucleolin or Sp1 to the promoter was independent of each other. Our results revealed that c-Jun/nucleolin and c-Jun/Sp1 complexes play an important role in PMA-regulated cPLA2alpha gene expression. It is likely that nucleolin binding at place of Sp1 on gene promoter could also mediate the regulation of c-Jun/Sp1-activated genes.
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Affiliation(s)
- Jen-Hui Tsou
- Department of Pharmacology, Department of Internal Medicine, College of Medicine, Center for Gene Regulation and Signal Transduction and Institute of Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Kwang-Yu Chang
- Department of Pharmacology, Department of Internal Medicine, College of Medicine, Center for Gene Regulation and Signal Transduction and Institute of Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Wei-Chiao Wang
- Department of Pharmacology, Department of Internal Medicine, College of Medicine, Center for Gene Regulation and Signal Transduction and Institute of Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Joseph T. Tseng
- Department of Pharmacology, Department of Internal Medicine, College of Medicine, Center for Gene Regulation and Signal Transduction and Institute of Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Wu-Chou Su
- Department of Pharmacology, Department of Internal Medicine, College of Medicine, Center for Gene Regulation and Signal Transduction and Institute of Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Liang-Yi Hung
- Department of Pharmacology, Department of Internal Medicine, College of Medicine, Center for Gene Regulation and Signal Transduction and Institute of Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Wen-Chang Chang
- Department of Pharmacology, Department of Internal Medicine, College of Medicine, Center for Gene Regulation and Signal Transduction and Institute of Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Ben-Kuen Chen
- Department of Pharmacology, Department of Internal Medicine, College of Medicine, Center for Gene Regulation and Signal Transduction and Institute of Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
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Dambara A, Morinaga T, Fukuda N, Yamakawa Y, Kato T, Enomoto A, Asai N, Murakumo Y, Matsuo S, Takahashi M. Nucleolin modulates the subcellular localization of GDNF-inducible zinc finger protein 1 and its roles in transcription and cell proliferation. Exp Cell Res 2007; 313:3755-66. [PMID: 17674968 DOI: 10.1016/j.yexcr.2007.07.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2007] [Revised: 06/12/2007] [Accepted: 07/03/2007] [Indexed: 10/23/2022]
Abstract
GZF1 is a zinc finger protein induced by glial cell-line-derived neurotrophic factor (GDNF). It is a sequence-specific transcriptional repressor with a BTB/POZ (Broad complex, Tramtrack, Bric a brac/Poxvirus and zinc finger) domain and ten zinc finger motifs. In the present study, we used immunoprecipitation and mass spectrometry to identify nucleolin as a GZF1-binding protein. Deletion analysis revealed that zinc finger motifs 1-4 of GZF1 mediate its association with nucleolin. When zinc fingers 1-4 were deleted from GZF1 or nucleolin expression was knocked down by short interference RNA (siRNA), nuclear localization of GZF1 was impaired. These results suggest that nucleolin is involved in the proper subcellular distribution of GZF1. In addition, overexpression of nucleolin moderately inhibited the transcriptional repressive activity of GZF1 whereas knockdown of nucleolin expression by siRNA enhanced its activity. Thus, the repressive activity of GZF1 is modulated by the level at which nucleolin is expressed. Finally, we found that knockdown of GZF1 and nucleolin expression markedly impaired cell proliferation. These findings suggest that the physiological functions of GZF1 may be regulated by the protein's association with nucleolin.
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Affiliation(s)
- Atsushi Dambara
- Department of Pathology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan
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Xie M, Kobayashi I, Kiyoshima T, Yamaza H, Honda JY, Takahashi K, Enoki N, Akamine A, Sakai H. Functional implication of nucleolin in the mouse first molar development. J Biol Chem 2007; 282:23275-83. [PMID: 17562718 DOI: 10.1074/jbc.m610779200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We examined the functional implication of nucleolin in the mouse first molar development. Both the nucleolin mRNA and protein expressions were demonstrated in the odontogenic epithelial cells in the early stage and in the inner enamel epithelial layer in the late stage. The expression pattern of nucleolin corresponded to the proliferating cells in the tooth germ, thus showing that nucleolin could possibly be related to cell proliferation. No in situ signal of nucleolin was found in the primary enamel knot (PEK). Furthermore, nucleolin protein was demonstrated in the PEK by immunohistochemistry. The existence of nucleolin protein in the PEK may possibly be related to the apoptosis in the PEK cells. An inhibition assay using the hemagglutinating virus of Japan-liposome containing nucleolin antisense phosphorothioated oligonucleotide (AS S-ODN) in cultured mouse mandibles at embryonic day (E) 11.0 showed a marked growth inhibition of tooth germ. Moreover, no developmental arrest was found in the cultured tooth germ at E15.0 treated with nucleolin AS S-ODN. Real time PCR was performed to examine the mRNA expression of nucleolin-related genes, and a significant reduction in the midkine mRNA expression was thus observed in the mouse mandible after being treated with nucleolin AS S-ODN. This inhibition assay indicated that nucleolin could thus be involved in the early stage of tooth germ initiation and morphogenesis, possibly by regulating the midkine expression.
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Affiliation(s)
- Ming Xie
- Laboratory of Oral Pathology and Medicine, Department of Endodontology and Operative Dentistry, Kyushu University, Graduate School of Dental Science, Fukuoka 812-8582, Japan
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26
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Mongelard F, Bouvet P. Nucleolin: a multiFACeTed protein. Trends Cell Biol 2007; 17:80-6. [PMID: 17157503 DOI: 10.1016/j.tcb.2006.11.010] [Citation(s) in RCA: 247] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Accepted: 11/30/2006] [Indexed: 11/28/2022]
Abstract
Nucleolin is an abundant, ubiquitously expressed protein that is found in various cell compartments, especially in the nucleolus, of which it is a major component. This multifunctional protein has been described as being a part of many pathways, from interactions with viruses at the cellular membrane to essential processing of the ribosomal RNA in the nucleolus. However, most of the molecular details of these different functions are not understood. Here, we focus on the role of nucleolin in transcription, especially some recent findings describing the protein as a histone chaperone [with functional similarity to the facilitates chromatin transcription (FACT) complex] and a chromatin co-remodeler. These new properties could help reconcile discrepancies in the literature regarding the role of nucleolin in transcription.
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Affiliation(s)
- Fabien Mongelard
- Laboratoire Joliot-Curie, Ecole Normale Supérieure de Lyon, 46 Allée d'Italie, 69007 Lyon, France
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27
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Rickards B, Flint SJ, Cole MD, LeRoy G. Nucleolin is required for RNA polymerase I transcription in vivo. Mol Cell Biol 2007; 27:937-48. [PMID: 17130237 PMCID: PMC1800701 DOI: 10.1128/mcb.01584-06] [Citation(s) in RCA: 94] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2006] [Revised: 10/04/2006] [Accepted: 11/14/2006] [Indexed: 11/20/2022] Open
Abstract
Eukaryotic genomes are packaged with histones and accessory proteins in the form of chromatin. RNA polymerases and their accessory proteins are sufficient for transcription of naked DNA, but not of chromatin, templates in vitro. In this study, we purified and identified nucleolin as a protein that allows RNA polymerase II to transcribe nucleosomal templates in vitro. As immunofluorescence confirmed that nucleolin localizes primarily to nucleoli with RNA polymerase I, we demonstrated that nucleolin allows RNA polymerase I transcription of chromatin templates in vitro. The results of chromatin immunoprecipitation experiments established that nucleolin is associated with chromatin containing rRNA genes transcribed by RNA polymerase I but not with genes transcribed by RNA polymerase II or III. Knockdown of nucleolin by RNA interference resulted in specific inhibition of RNA polymerase I transcription. We therefore propose that an important function of nucleolin is to permit RNA polymerase I to transcribe nucleolar chromatin.
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Affiliation(s)
- Brenden Rickards
- Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA
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28
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Birchenall-Roberts MC, Fu T, Kim SG, Huang YK, Dambach M, Resau JH, Ruscetti FW. K-Ras4B proteins are expressed in the nucleolus: Interaction with nucleolin. Biochem Biophys Res Commun 2006; 348:540-9. [PMID: 16889753 DOI: 10.1016/j.bbrc.2006.07.094] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2006] [Accepted: 07/17/2006] [Indexed: 11/17/2022]
Abstract
Kirsten Ras4B (K-Ras4B) is a potent onco-protein that is expressed in the majority of human cell types and is frequently mutated in carcinomas. K-Ras4B, like other members of the Ras family of proteins, is considered to be a cytoplasmic protein that must be localized to the plasma membrane for activation. Here, using confocal microscopy and biochemical analysis, we show that K-Ras4B, but not H-Ras or the closely related K-Ras4A, is also present in the nucleoli of normal and transformed cells. Subcellular fractionation and immunostaining show that K-Ras4B is located not only in the cytoplasm, but also in the nucleolar compartment. Modification of a C-terminal hexa-lysine motif unique to K-Ras4B results in exclusively cytoplasmic forms of the protein. Nucleolin, a pleiotropic regulator of cellular processes, including transcriptional regulation, is also characterized by a nucleolar-like nuclear appearance. We show that K-Ras4B and nucleolin co-localize within the nucleus and that nucleolin physically associates with K-Ras4B. Inhibition of K-Ras4B/nucleolin association blocked nucleolar localization of K-Ras4B. Using siRNA to knockdown the expression of nucleolin eliminated the nucleolar localization of K-Ras4B and significantly repressed the activation of the well-characterized K-Ras4B transcriptional target Ap-1, but stimulated Elk1. These data provide evidence of a nucleolar localization of K-Ras4B and describe a functional association between K-Ras4B and nucleolin.
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Affiliation(s)
- Maria C Birchenall-Roberts
- Basic Research Program, SAIC-Frederick, Inc., National Cancer Institute at Frederick, Frederick, MD 2170, USA.
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29
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Masumi A, Fukazawa H, Shimazu T, Yoshida M, Ozato K, Komuro K, Yamaguchi K. Nucleolin is involved in interferon regulatory factor-2-dependent transcriptional activation. Oncogene 2006; 25:5113-24. [PMID: 16582966 DOI: 10.1038/sj.onc.1209522] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Revised: 02/22/2006] [Accepted: 02/27/2006] [Indexed: 11/08/2022]
Abstract
We have previously shown that interferon regulatory factor-2 (IRF-2) is acetylated in a cell growth-dependent manner, which enables it to contribute to the transcription of cell growth-regulated promoters. To clarify the function of acetylation of IRF-2, we investigated the proteins that associate with acetylated IRF-2. In 293T cells, the transfection of p300/CBP-associated factor (PCAF) enhanced the acetylation of IRF-2. In cells transfected with both IRF-2 and PCAF, IRF-2 associated with endogenous nucleolin, while in contrast, minimal association was observed when IRF-2 was transfected with a PCAF histone acetyl transferase (HAT) deletion mutant. In a pull-down experiment using stable transfectants, acetylation-defective mutant IRF-2 (IRF-2K75R) recruited nucleolin to a much lesser extent than wild-type IRF-2, suggesting that nucleolin preferentially associates with acetylated IRF-2. Nucleolin in the presence of PCAF enhanced IRF-2-dependent H4 promoter activity in NIH3T3 cells. Nucleolin knock-down using siRNA reduced the IRF-2/PCAF-mediated promoter activity. Chromatin immunoprecipitation analysis indicated that PCAF transfection increased nucleolin binding to IRF-2 bound to the H4 promoter. We conclude that nucleolin is recruited to acetylated IRF-2, thereby contributing to gene regulation crucial for the control of cell growth.
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Affiliation(s)
- A Masumi
- Department of Safety Research on Blood and Biological Products, National Institute of Infectious Diseases, Musashimurayama-shi, Tokyo, Japan.
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30
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Kim H, Lee SH, Han JH, Lee JA, Cheang YH, Chang DJ, Lee YS, Kaang BK. A nucleolar protein ApLLP induces ApC/EBP expression required for long-term synaptic facilitation in aplysia neurons. Neuron 2006; 49:707-18. [PMID: 16504946 DOI: 10.1016/j.neuron.2006.01.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2005] [Revised: 06/07/2005] [Accepted: 01/26/2006] [Indexed: 10/25/2022]
Abstract
In Aplysia, long-term synaptic plasticity is induced by serotonin (5-HT) or neural activity and requires gene expression. Here, we demonstrate that ApLLP, a novel nucleolus protein, is critically involved in both long-term facilitation (LTF) and behavioral sensitization. Membrane depolarization induced ApLLP expression, which activated ApC/EBP expression through a direct binding to CRE. LTF was produced by a single pulse of 5-HT 30 min after the membrane depolarization. This LTF was blocked when either ApLLP or ApC/EBP were blocked by specific antibodies. In contrast, ApLLP overexpression induced LTF in response to a single 5-HT treatment. Simultaneously, a siphon noxious stimulus (SNS) to intact Aplysia induced ApLLP and ApC/EBP expression, and single tail shock 30 min after SNS transformed short-term sensitization to long-term sensitization of siphon withdrawal reflex. These results suggest that ApLLP is an activity-dependent transcriptional activator that switches short-term facilitation to long-term facilitation.
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Affiliation(s)
- Hyoung Kim
- National Research Laboratory, Institute of Molecular Biology and Genetics, School of Biological Sciences, College of Natural Sciences, Seoul National University, San 56-1 Silim-dong Kwanak-gu, Seoul 151-742, Korea
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31
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Angelov D, Bondarenko VA, Almagro S, Menoni H, Mongélard F, Hans F, Mietton F, Studitsky VM, Hamiche A, Dimitrov S, Bouvet P. Nucleolin is a histone chaperone with FACT-like activity and assists remodeling of nucleosomes. EMBO J 2006; 25:1669-79. [PMID: 16601700 PMCID: PMC1440837 DOI: 10.1038/sj.emboj.7601046] [Citation(s) in RCA: 189] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2005] [Accepted: 02/21/2006] [Indexed: 11/09/2022] Open
Abstract
Remodeling machines play an essential role in the control of gene expression, but how their activity is regulated is not known. Here we report that the nuclear protein nucleolin possesses a histone chaperone activity and that this factor greatly enhances the activity of the chromatin remodeling machineries SWI/SNF and ACF. Interestingly, nucleolin is able to induce the remodeling by SWI/SNF of macroH2A, but not of H2ABbd nucleosomes, which are otherwise resistant to remodeling. This new histone chaperone promotes the destabilization of the histone octamer, helping the dissociation of a H2A-H2B dimer, and stimulates the SWI/SNF-mediated transfer of H2A-H2B dimers. Furthermore, nucleolin facilitates transcription through the nucleosome, which is reminiscent of the activity of the FACT complex. This work defines new functions for histone chaperones in chromatin remodeling and regulation of transcription and explains how nucleolin could act on transcription.
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Affiliation(s)
- Dimitar Angelov
- Ecole Normale Supérieure de Lyon, CNRS-UMR 5161/INRA 1237/IFR128 Biosciences, Lyon-Gerland, France
- Laboratoire Joliot-Curie, Lyon, France
| | - Vladimir A Bondarenko
- Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Piscataway, NJ, USA
| | - Sébastien Almagro
- Ecole Normale Supérieure de Lyon, CNRS-UMR 5161/INRA 1237/IFR128 Biosciences, Lyon-Gerland, France
- Laboratoire Joliot-Curie, Lyon, France
| | - Hervé Menoni
- Ecole Normale Supérieure de Lyon, CNRS-UMR 5161/INRA 1237/IFR128 Biosciences, Lyon-Gerland, France
- Laboratoire Joliot-Curie, Lyon, France
| | - Fabien Mongélard
- Ecole Normale Supérieure de Lyon, CNRS-UMR 5161/INRA 1237/IFR128 Biosciences, Lyon-Gerland, France
- Laboratoire Joliot-Curie, Lyon, France
| | - Fabienne Hans
- Institut Albert Bonniot, INSERM U309, La Tronche Cedex, France
| | - Flore Mietton
- Institut Albert Bonniot, INSERM U309, La Tronche Cedex, France
| | - Vasily M Studitsky
- Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Piscataway, NJ, USA
| | - Ali Hamiche
- Institut André Lwoff, CNRS UPR 9079, Villejuif, France
| | - Stefan Dimitrov
- Laboratoire Joliot-Curie, Lyon, France
- Institut Albert Bonniot, INSERM U309, La Tronche Cedex, France
| | - Philippe Bouvet
- Ecole Normale Supérieure de Lyon, CNRS-UMR 5161/INRA 1237/IFR128 Biosciences, Lyon-Gerland, France
- Laboratoire Joliot-Curie, Lyon, France
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32
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Bernstein LR. Does nucleolin bind the NF kappa B DNA binding motif? Hepatology 2006; 43:376; author reply 376-7. [PMID: 16440351 DOI: 10.1002/hep.21027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
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33
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Wang YH, Chen YH, Lu JH, Tsai HJ. A 23-amino acid motif spanning the basic domain targets zebrafish myogenic regulatory factor myf5 into nucleolus. DNA Cell Biol 2005; 24:651-60. [PMID: 16225396 DOI: 10.1089/dna.2005.24.651] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Myf5 is a nuclear protein and one of the basic helix-loop-helix (bHLH) myogenic factors that play an important role in muscle specification and differentiation. The motif responsible for the nuclear translocation of Myf5 was unknown. Using on-line monitoring of EGFP (enhanced green fluorescent protein)-tagged zebrafish Myf5 translocation, we demonstrated that Myf5-EGFP protein resided in the nucleoplasm and nucleolus of zebrafish fibroblast cell lines (ZEM2S and ZF4), mammalian nonmuscle cell line (COS1), and muscle cell lines (RD and C2C12). In contrast, zebrafish MyoD-EGFP was localized in the nucleus but did not condense in the nucleolus. Using indirect immunofluorescent staining, we determined that zebrafish Myf5 was colocalized with nucleophosmin/B23, a nucleolus protein. Deletion analysis revealed that amino acid residues 60 to 82 (60KRKASTVDRRRAATMRERRRLKK82) of Myf5 were sufficient and necessary for nucleolus targeting. A GST pulldown assay followed by Western analysis showed that nucleolin/C23 could be pulled down specifically by GST-Myf5, but not by GST-MyoD. Based on these findings, we propose that the distinct functions of Myf5 and MyoD may result from their differential binding affinity to nucleolin/C23.
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Affiliation(s)
- Yun-Hsin Wang
- Institute of Molecular and Cellular Biology, National Taiwan University, Taipei, Taiwan, Republic of China.
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Bartusel T, Schubert S, Klempnauer KH. Regulation of the cyclin D1 and cyclin A1 promoters by B-Myb is mediated by Sp1 binding sites. Gene 2005; 351:171-80. [PMID: 15922873 DOI: 10.1016/j.gene.2005.03.035] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2004] [Revised: 02/21/2005] [Accepted: 03/22/2005] [Indexed: 11/25/2022]
Abstract
B-Myb is a highly conserved member of the Myb family of transcription factors which plays an important role during the cell cycle. Previous work has shown that B-Myb is phosphorylated at several sites by cyclin A/Cdk2 in the early S-phase. These phosphorylations increase the transactivation potential of B-Myb by counteracting the repressive function of an inhibitory domain located at the carboxyl-terminus of B-Myb. As yet, only a few genes have been identified as B-Myb target genes. Previous work has suggested that the cyclin D1 gene might be regulated by B-Myb. Here, we have studied the effect of B-Myb on the promoter of the cyclin D1 gene. We show that B-Myb is a potent activator of the cyclin D1 promoter and that this activation is not mediated by Myb binding sites but rather by a group of Sp1 binding sites which have previously been shown to be crucial for cyclin D1 promoter activity. Our data show that the C-terminal domain of B-Myb is required for the activation of the cyclin D1 promoter and that this part of B-Myb interacts with Sp1. Finally, we have found that the promoter of the cyclin A1 gene is also activated by B-Myb by a Sp1 binding site-dependent mechanism. The effect of B-Myb on the promoters of the cyclin A1 and D1 genes is reminiscent of the mechanism that has been proposed for the autoregulation of the B-myb promoter by B-Myb, which also involves Sp1 binding sites. Taken together, our identification of two novel B-Myb responsive promoters whose activation by B-Myb does not involve Myb binding sites extends previous evidence for the existence of a distinct mechanism of transactivation by B-Myb which is dependent on Sp1 binding sites. The observation that this mechanism is not subject to the inhibitory effect of the C-terminal domain of B-Myb but rather requires this domain supports the notion that the Sp1 site-dependent mechanism is already active in the G1-phase prior to the phosphorylation of B-Myb by cyclin A/Cdk2.
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Affiliation(s)
- Thorsten Bartusel
- Institut für Biochemie, Westfälische-Wilhelms-Universität Münster, Germany
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35
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Kim K, Dimitrova DD, Carta KM, Saxena A, Daras M, Borowiec JA. Novel checkpoint response to genotoxic stress mediated by nucleolin-replication protein a complex formation. Mol Cell Biol 2005; 25:2463-74. [PMID: 15743838 PMCID: PMC1061594 DOI: 10.1128/mcb.25.6.2463-2474.2005] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2004] [Revised: 06/14/2004] [Accepted: 12/13/2004] [Indexed: 11/20/2022] Open
Abstract
Human replication protein A (RPA), the primary single-stranded DNA-binding protein, was previously found to be inhibited after heat shock by complex formation with nucleolin. Here we show that nucleolin-RPA complex formation is stimulated after genotoxic stresses such as treatment with camptothecin or exposure to ionizing radiation. Complex formation in vitro and in vivo requires a 63-residue glycine-arginine-rich (GAR) domain located at the extreme C terminus of nucleolin, with this domain sufficient to inhibit DNA replication in vitro. Fluorescence resonance energy transfer studies demonstrate that the nucleolin-RPA interaction after stress occurs both in the nucleoplasm and in the nucleolus. Expression of the GAR domain or a nucleolin mutant (TM) with a constitutive interaction with RPA is sufficient to inhibit entry into S phase. Increasing cellular RPA levels by overexpression of the RPA2 subunit minimizes the inhibitory effects of nucleolin GAR or TM expression on chromosomal DNA replication. The arrest is independent of p53 activation by ATM or ATR and does not involve heightened expression of p21. Our data reveal a novel cellular mechanism that represses genomic replication in response to genotoxic stress by inhibition of an essential DNA replication factor.
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Affiliation(s)
- Kyung Kim
- Department of Biochemistry, New York University School of Medicine, 550 First Ave., MSB-383, New York, NY 10016, USA
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36
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Sakaguchi M, Miyazaki M, Takaishi M, Sakaguchi Y, Makino E, Kataoka N, Yamada H, Namba M, Huh NH. S100C/A11 is a key mediator of Ca(2+)-induced growth inhibition of human epidermal keratinocytes. J Cell Biol 2003; 163:825-35. [PMID: 14623863 PMCID: PMC2173690 DOI: 10.1083/jcb.200304017] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2003] [Accepted: 09/29/2003] [Indexed: 11/22/2022] Open
Abstract
An increase in extracellular Ca2+ induces growth arrest and differentiation of human keratinocytes in culture. We examined possible involvement of S100C/A11 in this growth regulation. On exposure of the cells to high Ca2+, S100C/A11 was specifically phosphorylated at 10Thr and 94Ser. Phosphorylation facilitated the binding of S100C/A11 to nucleolin, resulting in nuclear translocation of S100C/A11. In nuclei, S100C/A11 liberated Sp1/3 from nucleolin. The resulting free Sp1/3 transcriptionally activated p21CIP1/WAF1, a representative negative regulator of cell growth. Introduction of anti-S100C/A11 antibody into the cells largely abolished the growth inhibition induced by Ca2+ and the induction of p21CIP1/WAF1. In the human epidermis, S100C/A11 was detected in nuclei of differentiating cells in the suprabasal layers, but not in nuclei of proliferating cells in the basal layer. These results indicate that S100C/A11 is a key mediator of the Ca(2+)-induced growth inhibition of human keratinocytes in culture, and that it may be possibly involved in the growth regulation in vivo as well.
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Affiliation(s)
- Masakiyo Sakaguchi
- Department of Cell Biology, Okayama University Graduate School of Medicine and Dentistry, Okayama 700-8558, Japan
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37
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Ito T, Fujihara M, Oda A, Wakamoto S, Yamaguchi M, Komatsu N, Miyazaki H, Azuma H, Ikeda H, Ikebuchi K. Thrombopoietin upregulates nucleolin mRNA and protein in thrombopoietin-dependent megakaryocytic cell line, UT-7/TPO. Mol Cell Biochem 2003; 247:75-82. [PMID: 12841634 DOI: 10.1023/a:1024184116764] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Thrombopoietin (TPO) is a hematopoietic cytokine that regulates megakaryocytosis and thrombocytosis by binding to its receptor (c-Mpl). The signaling pathways downstream of c-Mpl include the Ras/Raf/MAP kinase and JAK/STAT pathway and are transduced into the regulation of immediate early-, early- and delayed-response genes. How these genes couple c-Mpl activation to the biochemical machinery of cell growth and cell cycle progression in hematopoietic cells is still unclear. UT-7/TPO is a recently characterized TPO-dependent cell line. Using RNA fingerprinting with arbitrarily primed PCR (RAP-PCR) to identify the TPO-regulated genes in this cell line, we found that the mRNA expression of nucleolin was upregulated in the UT-7/TPO cells in response to TPO. Concomitantly, the TPO-stimulated cells expressed an increased amount of full length nucleolin as determined by immunoblot analysis. The TPO-induced upregulation of nucleolin mRNA was not inhibited by the MEK1/2 inhibitor PD98059, suggesting that ERK/MAPK activation is not necessary for elevation of nucleolin gene expression in response to TPO in UT-7/TPO. Nucleolin is a multifunctional nucleolar protein thought to be involved in many cellular processes, including ribosome biogenesis, the processing of ribosomal RNA (rRNA), mRNA stability, transcriptional regulation, and cell proliferation. Thus, these results indicate that the upregulation of nucleolin mRNA and protein may be important for the TPO-induced effects of hematopoietic cells.
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Affiliation(s)
- Takatoshi Ito
- Japanese Red Cross, Hokkaido Red Cross Blood Center, Sapporo, Japan
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38
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Petrovas C, Jeay S, Lewis RE, Sonenshein GE. B-Myb repressor function is regulated by cyclin A phosphorylation and sequences within the C-terminal domain. Oncogene 2003; 22:2011-20. [PMID: 12673206 DOI: 10.1038/sj.onc.1206231] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
B-Myb is a widely expressed member of the myb oncogene family that has been shown to act as either an activator or repressor of gene transcription in a cell-type-specific fashion. For example, in aortic smooth muscle cells B-Myb represses transcription of the alpha2(V) collagen gene. Recently, phosphorylation of B-Myb by cyclin A was shown to enhance greatly its ability to transactivate. Here, we have tested the effects of cyclin A on the ability of B-Myb to repress. We report that coexpression of cyclin A abolished repression of the alpha2(V) collagen promoter, whereas a dominant-negative cyclin-dependent kinase 2 (cdk2) enhanced repression by ectopic and endogenous B-Myb protein. Mutation of 10 of 22 putative cyclin A sites, which greatly reduces the effects of cyclin A on transactivation by B-Myb, had no effect on the ability of cyclin A to alleviate B-Myb-mediated repression of alpha2(V) collagen promoter activity. Furthermore, the stability of the mutant B-Myb protein was largely unaffected by cyclin A, although ectopic expression of cyclin A enhanced the rate of decay of wild-type B-Myb protein. Thus, the mechanisms of repression and activation appear distinct, for example, mediated by different critical phosphorylation sites or protein-protein interactions. B-Myb mutants with either deletion of aa 374-581 (B-Myb-Mut3) or C-terminal truncation beyond aa 491 (B-Myb-491) positively regulated alpha2(V) collagen promoter activity, and were not affected by cyclin A. Thus, our findings indicate that the ability of B-Myb to function as a repressor of matrix promoter activity is abolished by cyclin A, and maps the sites mediating negative regulation by B-Myb to the region between aa 491 and 582.
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Seong HA, Kim KT, Ha H. Enhancement of B-MYB transcriptional activity by ZPR9, a novel zinc finger protein. J Biol Chem 2003; 278:9655-62. [PMID: 12645566 DOI: 10.1074/jbc.m207478200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
By using the yeast two-hybrid system, the zinc finger protein ZPR9 was identified as one of the B-MYB interacting proteins that associates with the carboxyl-terminal conserved region of B-MYB. ZPR9 was found to form in vivo complexes with B-MYB, as demonstrated by in vivo binding assay and coimmunoprecipitation experiments of the endogenously and exogenously expressed proteins. Deletion analysis revealed that this binding was mediated by all three functional domains, an amino-terminal DNA-binding domain, a transactivation domain, and a carboxyl-terminal conserved region of B-MYB. We show that the interaction of ZPR9 with B-MYB is functional because cotransfection of ZPR9 significantly up-regulates B-MYB transcriptional activity in a dose-dependent manner. In addition, coexpression of ZPR9 with B-MYB caused the accumulation of B-MYB, as well as ZPR9, in the nucleus. Furthermore, constitutive expression of ZPR9 in human neuroblastoma cells induces apoptosis in the presence of retinoic acid. These results strongly suggest that ZPR9 plays an important role in modulation of the transactivation by B-MYB and cellular growth of neuroblastoma cells.
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Affiliation(s)
- Hyun-A Seong
- Department of Biochemistry, School of Life Sciences, Research Center for Bioresource and Health, Chungbuk National University, Cheongju 361-763, Republic of Korea
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40
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Dubois T, Zemlickova E, Howell S, Aitken A. Centaurin-alpha 1 associates in vitro and in vivo with nucleolin. Biochem Biophys Res Commun 2003; 301:502-8. [PMID: 12565890 DOI: 10.1016/s0006-291x(02)03010-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Centaurin-alpha(1) was originally described as a binding partner for phosphoinositides. In spite of the presence of a putative ADP-ribosylation factor (ARF) GTPase-activating protein (GAP) domain, no ARF-GAP activity has been attributed to centaurin-alpha(1) so far. Thus the function of this protein remains to be determined. In order to better understand its intracellular role, we aimed to identify centaurin-alpha(1) partners. Using affinity chromatography followed by mass spectrometry analysis, we identified several potential centaurin-alpha(1) protein partners. Nucleolin, a nucleolar protein involved in ribosome biosynthesis, was the main centaurin-alpha(1) interacting protein. The interaction between centaurin-alpha(1) and nucleolin was confirmed by Western blot analysis and GST pull down assays. Moreover, we have shown that ectopically expressed centaurin-alpha(1) associates in vivo with endogenous nucleolin in human embryonic kidney 293 cells. In addition, the association between nucleolin and centaurin-alpha(1) was disrupted by RNAse treatment, indicating that RNA integrity was necessary for their binding. This suggested that centaurin-alpha(1) was part of a ribonucleoprotein complex.
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Affiliation(s)
- Thierry Dubois
- Division of Biomedical and Clinical Laboratory Sciences, The University of Edinburgh, Hugh Robson Building, George Square, Edinburgh EH8 9XD, UK.
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41
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Gaillard C, Le Rouzic E, Créminon C, Perbal B. Alteration of C-MYB DNA binding to cognate responsive elements in HL-60 variant cells. Mol Pathol 2002; 55:325-35. [PMID: 12354938 PMCID: PMC1187265 DOI: 10.1136/mp.55.5.325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2002] [Indexed: 02/04/2023]
Abstract
AIMS To establish whether the MYB protein expressed in HL-60 variant cells, which are cells resistant to 12-O-tetradecanoylphorbol-13-acetate (TPA) induced differentiation, is able to bind MYB recognition elements (MREs) involved in the transcriptional regulation of myb target genes. In addition, to determine whether alterations in the binding of the MYB protein to MREs affects HL-60 cell proliferation and differentiation. METHODS Nuclear extracts of HL-60 variant cells exhibiting different degrees of resistance to TPA induced monocytic differentiation were used in electrophoretic mobility shift experiments (EMSAs), bandshift experiments performed with labelled oliogonucleotides containing the MYB consensus binding sequences. RESULTS The MYB protein contained in nuclear extracts from HL-60 variant cells did not bind efficiently to the MYB recognition elements identified in the mim-1 and PR264 promoters. Molecular cloning of the myb gene and analysis of the MYB protein expressed in the HL-60 variant cells established that the lack of binding did not result from a structural alteration of MYB in these cells. The lack of MRE binding did not abrogate the ability of variant HL-60s to proliferate and to undergo differentiation. Furthermore, the expression of the PR264/SC35 splicing factor was not affected as a result of the altered MYB DNA binding activity. CONCLUSIONS Because the MYB protein expressed in HL-60 variant cells did not appear to be structurally different from the MYB protein expressed in parental HL-60 cells, it is possible that the HL-60 variant cells contain a MYB binding inhibitory factor (MBIF) that interferes with MYB binding on MREs. The increased proliferation rate of HL-60 variant cells and their reduced serum requirement argues against the need for direct MYB binding in the regulation of cell growth.
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Affiliation(s)
- C Gaillard
- Laboratoire d'Oncologie Virale et Moléculaire, UFR de Biochimie, Université Paris 7 D Diderot, 75005 Paris, France
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42
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Gabellini D, Green MR, Tupler R. Inappropriate gene activation in FSHD: a repressor complex binds a chromosomal repeat deleted in dystrophic muscle. Cell 2002; 110:339-48. [PMID: 12176321 DOI: 10.1016/s0092-8674(02)00826-7] [Citation(s) in RCA: 275] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Facioscapulohumeral muscular dystrophy (FSHD), a common myopathy, is an autosomal dominant disease of unknown molecular mechanism. Almost all FSHD patients carry deletions of an integral number of tandem 3.3 kilobase repeats, termed D4Z4, located on chromosome 4q35. Here, we find that in FSHD muscle, 4q35 genes located upstream of D4Z4 are inappropriately overexpressed. We show that an element within D4Z4 specifically binds a multiprotein complex consisting of YY1, a known transcriptional repressor, HMGB2, an architectural protein, and nucleolin. We demonstrate that this multiprotein complex binds D4Z4 in vitro and in vivo and mediates transcriptional repression of 4q35 genes. Based upon these results, we propose that deletion of D4Z4 leads to the inappropriate transcriptional derepression of 4q35 genes resulting in disease.
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MESH Headings
- Animals
- Chromosomes, Human, Pair 4/genetics
- Disease Models, Animal
- Gene Deletion
- Gene Expression Regulation/genetics
- HeLa Cells
- Humans
- Mice
- Mice, Mutant Strains
- Muscle Proteins/biosynthesis
- Muscle Proteins/genetics
- Muscle, Skeletal/metabolism
- Muscle, Skeletal/pathology
- Muscle, Skeletal/physiopathology
- Muscular Dystrophy, Facioscapulohumeral/genetics
- Muscular Dystrophy, Facioscapulohumeral/metabolism
- Muscular Dystrophy, Facioscapulohumeral/physiopathology
- Repressor Proteins/genetics
- Tandem Repeat Sequences/genetics
- Transcriptional Activation
- Up-Regulation/genetics
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Affiliation(s)
- Davide Gabellini
- Howard Hughes Medical Institute, Program in Gene Function and Expression, Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, MA 01605, USA
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43
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Daniely Y, Dimitrova DD, Borowiec JA. Stress-dependent nucleolin mobilization mediated by p53-nucleolin complex formation. Mol Cell Biol 2002; 22:6014-22. [PMID: 12138209 PMCID: PMC133981 DOI: 10.1128/mcb.22.16.6014-6022.2002] [Citation(s) in RCA: 127] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2002] [Accepted: 05/08/2002] [Indexed: 01/10/2023] Open
Abstract
We recently discovered that heat shock causes nucleolin to relocalize from the nucleolus to the nucleoplasm, whereupon it binds replication protein A and inhibits DNA replication initiation. We report that nucleolin mobilization also occurs following exposure to ionizing radiation (IR) and treatment with camptothecin. Mobilization was selective in that another nucleolar marker, upstream binding factor, did not relocalize in response to IR. Nucleolin relocalization was dependent on p53 and stress, the latter initially stimulating nucleolin-p53 complex formation. Nucleolin relocalization and complex formation in vivo were independent of p53 transactivation but required the p53 C-terminal regulatory domain. Nucleolin and p53 also interact directly in vitro, with a similar requirement for p53 domains. These data indicate a novel p53-dependent mechanism in which cell stress mobilizes nucleolin for transient replication inhibition and DNA repair.
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Affiliation(s)
- Yaron Daniely
- Department of Biochemistry and Kaplan Comprehensive Cancer Center, New York University School of Medicine, New York, New York 10016, USA
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44
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Vailleau F, Daniel X, Tronchet M, Montillet JL, Triantaphylidès C, Roby D. A R2R3-MYB gene, AtMYB30, acts as a positive regulator of the hypersensitive cell death program in plants in response to pathogen attack. Proc Natl Acad Sci U S A 2002; 99:10179-84. [PMID: 12119395 PMCID: PMC126644 DOI: 10.1073/pnas.152047199] [Citation(s) in RCA: 190] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2002] [Indexed: 02/06/2023] Open
Abstract
Hypersensitive response (HR) is a programmed cell death that is commonly associated with disease resistance in plants. Among the different HR-related early induced genes, the AtMYB30 gene is specifically, rapidly, and transiently expressed during incompatible interactions between Arabidopsis and bacterial pathogens. Its expression was also shown to be deregulated in Arabidopsis mutants affected in the control of cell death initiation. Here, we demonstrate that overexpression in Arabidopsis and tobacco of AtMYB30 (i) accelerates and intensifies the appearance of the HR in response to different avirulent bacterial pathogens, (ii) causes HR-like responses to virulent strains, and (iii) increases resistance against different bacterial pathogens, and a virulent biotrophic fungal pathogen, Cercospora nicotianae. In antisense AtMYB30 Arabidopsis lines, HR cell death is strongly decreased or suppressed in response to avirulent bacterial strains, resistance against different bacterial pathogens decreased, and the expression of HR- and defense-related genes was altered. Taken together, these results strongly suggest that AtMYB30 is a positive regulator of hypersensitive cell death.
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Affiliation(s)
- Fabienne Vailleau
- Laboratoire de Biologie Moléculaire des Relations Plantes-Microorganismes, Unité Mixte de Recherche Centre National de la Recherche Scientifique/Institut National de la Recherche Agronomique 215, BP 27, 31326 Castanet-Tolosan Cedex, France
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Monticelli S, Ghittoni R, Kabesch M, Vercelli D. Myb proteins repress human Ig epsilon germline transcription by inhibiting STAT6-dependent promoter activation. Mol Immunol 2002; 38:1129-38. [PMID: 12044779 DOI: 10.1016/s0161-5890(02)00037-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Cytokine-dependent induction of correctly spliced germline (GL) transcripts is required to target the appropriate switch region for class switch recombination. GL transcription is linked to the cell cycle and the number of cell divisions through mechanisms that have not been defined. The human proximal epsilon GL promoter contains an IL-4 responsive element (IL-4RE) that binds STAT6 and is sufficient to confer IL-4 inducibility to a heterologous promoter in transient transfection studies. We show herein that the IL-4RE contains a novel Myb binding motif that overlaps the 3' end of the STAT6 palindrome. EMSA analysis showed binding to the IL-4RE of endogenous Myb proteins expressed in BL-2 B cells and Jurkat T cells. However, double occupancy of a probe spanning both STAT6 and Myb binding motifs could not be detected. Thus, binding of either factor may prevent protein/DNA interactions at the other site, raising the possibility that Myb binding may interfere with STAT6-dependent activation of the IL-4RE. Indeed, cotransfection of A-Myb or c-Myb expression vectors in HEK293 and BL-2 cells suppressed STAT6-dependent transcription from a reporter construct containing four copies of the IL-4RE cloned upstream of a minimal thymidine kinase promoter. Most importantly, overexpression of A-Myb was sufficient to suppress IL-4-induced endogenous epsilon GL transcription in BL-2 cells. Our results indicate that Myb proteins, which are known to act as cell cycle sensors, may play an important mechanistic role in the in vivo regulation of epsilon GL transcription in human B cells.
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Affiliation(s)
- Silvia Monticelli
- Arizona Respiratory Center, College of Medicine, University of Arizona, 1501 N. Campbell Avenue, Tucson, AZ 85724, USA
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46
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Yang C, Maiguel DA, Carrier F. Identification of nucleolin and nucleophosmin as genotoxic stress-responsive RNA-binding proteins. Nucleic Acids Res 2002; 30:2251-60. [PMID: 12000845 PMCID: PMC115285 DOI: 10.1093/nar/30.10.2251] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2001] [Revised: 03/15/2002] [Accepted: 03/15/2002] [Indexed: 01/25/2023] Open
Abstract
Genotoxic stress (DNA damage) can elicit multiple responses in mammalian cells, including the activation of numerous cascades of signal transduction that result in the activation of cellular genes involved in growth control, DNA repair and apoptosis. In an earlier report, we have shown that DNA-damaging agents can also induce the RNA-binding activity of several specific proteins that favor a double stem-loop RNA structure. Here we report the purification and identification of nucleophosmin (NPM) and nucleolin as two genotoxic stress-responsive RNA-binding proteins. UV radiation induces the protein expression levels and RNA-binding activity of NPM while nucleolin RNA-binding activity increases after UV or ionizing radiation exposure. Moreover, we have identified 40 mRNA ligands that are potentially regulated by nucleolin, several of which are stress-responsive transcripts. In addition, our data indicate that activation of nucleolin RNA-binding activity by genotoxic stress is mediated by stress-activated protein kinase p38. Our findings suggest that activation of the RNA-binding properties of nucleolin and NPM is part of the cellular response to genotoxic stress.
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Affiliation(s)
- Chonglin Yang
- University of Maryland, Baltimore, School of Medicine, Biochemistry and Molecular Biology Department, 108 North Greene Street, Baltimore, MD 21201-1503, USA
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Reichler SA, Balk J, Brown ME, Woodruff K, Clark GB, Roux SJ. Light differentially regulates cell division and the mRNA abundance of pea nucleolin during de-etiolation. PLANT PHYSIOLOGY 2001; 125:339-50. [PMID: 11154341 PMCID: PMC61014 DOI: 10.1104/pp.125.1.339] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2000] [Revised: 03/23/2000] [Accepted: 08/03/2000] [Indexed: 05/19/2023]
Abstract
The abundance of plant nucleolin mRNA is regulated during de-etiolation by phytochrome. A close correlation between the mRNA abundance of nucleolin and mitosis has also been previously reported. These results raised the question of whether the effects of light on nucleolin mRNA expression were a consequence of light effects on mitosis. To test this we compared the kinetics of light-mediated increases in cell proliferation with that of light-mediated changes in the abundance of nucleolin mRNA using plumules of dark-grown pea (Pisum sativum) seedlings. These experiments show that S-phase increases 9 h after a red light pulse, followed by M-phase increases in the plumule leaves at 12 h post-irradiation, a time course consistent with separately measured kinetics of red light-induced increases in the expression of cell cycle-regulated genes. These increases in cell cycle-regulated genes are photoreversible, implying that the light-induced increases in cell proliferation are, like nucleolin mRNA expression, regulated via phytochrome. Red light stimulates increases in the mRNA for nucleolin at 6 h post-irradiation, prior to any cell proliferation changes and concurrent with the reported timing of phytochrome-mediated increases of rRNA abundance. After a green light pulse, nucleolin mRNA levels increase without increasing S-phase or M-phase. Studies in animals and yeast indicate that nucleolin plays a significant role in ribosome biosynthesis. Consistent with this function, pea nucleolin can rescue nucleolin deletion mutants of yeast that are defective in rRNA synthesis. Our data show that during de-etiolation, the increased expression of nucleolin mRNA is more directly regulated by light than by mitosis.
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Affiliation(s)
- S A Reichler
- Section of Molecular Cell and Developmental Biology, University of Texas, Austin, Texas 78713, USA
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48
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The Regulation of Enzymatic Activity and Metabolism. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50014-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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49
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Grotewold E, Sainz MB, Tagliani L, Hernandez JM, Bowen B, Chandler VL. Identification of the residues in the Myb domain of maize C1 that specify the interaction with the bHLH cofactor R. Proc Natl Acad Sci U S A 2000; 97:13579-84. [PMID: 11095727 PMCID: PMC17618 DOI: 10.1073/pnas.250379897] [Citation(s) in RCA: 231] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The maize Myb transcription factor C1 depends on the basic helix-loop-helix (bHLH) proteins R or B for regulatory function, but the closely related Myb protein P does not. We have used the similarity between the Myb domains of C1 and P to identify residues that specify the interaction between the Myb domain of C1 and the N-terminal region of R. Substitution of four predicted solvent-exposed residues in the first helix of the second Myb repeat of P with corresponding residues from C1 is sufficient to confer on P the ability to physically interact with R. However, two additional Myb domain amino acid changes are needed to make the P regulatory activity partially dependent on R in maize cells. Interestingly, when P is altered so that it interacts with R, it can activate the Bz1 promoter, normally regulated by C1 + R but not by P. Together, these findings demonstrate that the change of a few amino acids within highly similar Myb domains can mediate differential interactions with a transcriptional coregulator that plays a central role in the regulatory specificity of C1, and that Myb domains play important roles in combinatorial transcriptional regulation.
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Affiliation(s)
- E Grotewold
- Department of Plant Biology and Plant Biotechnology Center, Ohio State University, Columbus, OH 43210, USA. 1Wosu.edu
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50
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Monsalve M, Wu Z, Adelmant G, Puigserver P, Fan M, Spiegelman BM. Direct coupling of transcription and mRNA processing through the thermogenic coactivator PGC-1. Mol Cell 2000; 6:307-16. [PMID: 10983978 DOI: 10.1016/s1097-2765(00)00031-9] [Citation(s) in RCA: 307] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Transcription and mRNA processing are coupled events in vivo, but the mechanisms that coordinate these processes are largely unknown. PGC-1 is a transcriptional coactivator that plays a major role in the regulation of adaptive thermogenesis. PGC-1 also has certain motifs characteristic of splicing factors. We demonstrate here that mutations in the serine- and arginine-rich domain and RNA recognition motif of PGC-1 interfere with the ability of PGC-1 to induce mRNAs of target genes. These mutations also disrupt the ability of PGC-1 to co-localize and associate with RNA processing factors. PGC-1 can alter the processing of an mRNA, but only when it is loaded onto the promoter of the gene. These data demonstrate the coordinated regulation of RNA transcription and processing through PGC-1.
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Affiliation(s)
- M Monsalve
- Dana-Farber Cancer Institute and The Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA
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