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Karakostis K, Malbert-Colas L, Thermou A, Vojtesek B, Fåhraeus R. The DNA damage sensor ATM kinase interacts with the p53 mRNA and guides the DNA damage response pathway. Mol Cancer 2024; 23:21. [PMID: 38263180 PMCID: PMC10804554 DOI: 10.1186/s12943-024-01933-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 01/02/2024] [Indexed: 01/25/2024] Open
Abstract
BACKGROUND The ATM kinase constitutes a master regulatory hub of DNA damage and activates the p53 response pathway by phosphorylating the MDM2 protein, which develops an affinity for the p53 mRNA secondary structure. Disruption of this interaction prevents the activation of the nascent p53. The link of the MDM2 protein-p53 mRNA interaction with the upstream DNA damage sensor ATM kinase and the role of the p53 mRNA in the DNA damage sensing mechanism, are still highly anticipated. METHODS The proximity ligation assay (PLA) has been extensively used to reveal the sub-cellular localisation of the protein-mRNA and protein-protein interactions. ELISA and co-immunoprecipitation confirmed the interactions in vitro and in cells. RESULTS This study provides a novel mechanism whereby the p53 mRNA interacts with the ATM kinase enzyme and shows that the L22L synonymous mutant, known to alter the secondary structure of the p53 mRNA, prevents the interaction. The relevant mechanistic roles in the DNA Damage Sensing pathway, which is linked to downstream DNA damage response, are explored. Following DNA damage (double-stranded DNA breaks activating ATM), activated MDMX protein competes the ATM-p53 mRNA interaction and prevents the association of the p53 mRNA with NBS1 (MRN complex). These data also reveal the binding domains and the phosphorylation events on ATM that regulate the interaction and the trafficking of the complex to the cytoplasm. CONCLUSION The presented model shows a novel interaction of ATM with the p53 mRNA and describes the link between DNA Damage Sensing with the downstream p53 activation pathways; supporting the rising functional implications of synonymous mutations altering secondary mRNA structures.
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Affiliation(s)
- Konstantinos Karakostis
- Inserm UMRS1131, Institut de Génétique Moléculaire, Paris Cité Université, Hôpital St. Louis, Paris, France.
- Institut de Biotecnologia I de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra (Barcelona), Spain.
| | - Laurence Malbert-Colas
- Inserm UMRS1131, Institut de Génétique Moléculaire, Paris Cité Université, Hôpital St. Louis, Paris, France
| | - Aikaterini Thermou
- Inserm UMRS1131, Institut de Génétique Moléculaire, Paris Cité Université, Hôpital St. Louis, Paris, France
| | - Borek Vojtesek
- Research Centre for Applied Molecular Oncology (RECAMO), Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - Robin Fåhraeus
- Inserm UMRS1131, Institut de Génétique Moléculaire, Paris Cité Université, Hôpital St. Louis, Paris, France.
- Research Centre for Applied Molecular Oncology (RECAMO), Masaryk Memorial Cancer Institute, Brno, Czech Republic.
- Department of Medical Biosciences, Umeå University, Umeå, 90185, Sweden.
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2
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Zheng AJL, Thermou A, Daskalogianni C, Malbert-Colas L, Karakostis K, Le Sénéchal R, Trang Dinh V, Tovar Fernandez MC, Apcher S, Chen S, Blondel M, Fahraeus R. The nascent polypeptide-associated complex (NAC) controls translation initiation in cis by recruiting nucleolin to the encoding mRNA. Nucleic Acids Res 2022; 50:10110-10122. [PMID: 36107769 PMCID: PMC9508830 DOI: 10.1093/nar/gkac751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 09/10/2022] [Indexed: 11/20/2022] Open
Abstract
Protein aggregates and abnormal proteins are toxic and associated with neurodegenerative diseases. There are several mechanisms to help cells get rid of aggregates but little is known on how cells prevent aggregate-prone proteins from being synthesised. The EBNA1 of the Epstein-Barr virus (EBV) evades the immune system by suppressing its own mRNA translation initiation in order to minimize the production of antigenic peptides for the major histocompatibility (MHC) class I pathway. Here we show that the emerging peptide of the disordered glycine–alanine repeat (GAr) within EBNA1 dislodges the nascent polypeptide-associated complex (NAC) from the ribosome. This results in the recruitment of nucleolin to the GAr-encoding mRNA and suppression of mRNA translation initiation in cis. Suppressing NAC alpha (NACA) expression prevents nucleolin from binding to the GAr mRNA and overcomes GAr-mediated translation inhibition. Taken together, these observations suggest that EBNA1 exploits a nascent protein quality control pathway to regulate its own rate of synthesis that is based on sensing the nascent GAr peptide by NAC followed by the recruitment of nucleolin to the GAr-encoding RNA sequence.
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Affiliation(s)
- Alice J L Zheng
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
| | - Aikaterini Thermou
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
- ICCVS, University of Gdańsk , Science, ul. Wita Stwosza 63 , 80-308 Gdańsk , Poland
| | - Chrysoula Daskalogianni
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
- ICCVS, University of Gdańsk , Science, ul. Wita Stwosza 63 , 80-308 Gdańsk , Poland
| | - Laurence Malbert-Colas
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
| | - Konstantinos Karakostis
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
| | - Ronan Le Sénéchal
- Inserm UMR 1078, Université de Bretagne Occidentale (UBO), Etablissement Français du Sang (EFS) Bretagne, CHRU Brest , 29200 , Brest , France
| | - Van Trang Dinh
- Inserm UMR 1078, Université de Bretagne Occidentale (UBO), Etablissement Français du Sang (EFS) Bretagne, CHRU Brest , 29200 , Brest , France
| | - Maria C Tovar Fernandez
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
- ICCVS, University of Gdańsk , Science, ul. Wita Stwosza 63 , 80-308 Gdańsk , Poland
| | - Sébastien Apcher
- Institut Gustave Roussy, Université Paris Sud, Unité 1015 département d’immunologie , 114, rue Edouard Vaillant , 94805 Villejuif , France
| | - Sa Chen
- Department of Medical Biosciences, Building 6M, Umeå University , 901 85 Umeå , Sweden
| | - Marc Blondel
- Inserm UMR 1078, Université de Bretagne Occidentale (UBO), Etablissement Français du Sang (EFS) Bretagne, CHRU Brest , 29200 , Brest , France
| | - Robin Fahraeus
- Inserm UMRS 1131, Institut de Génétique Moléculaire, Université de Paris, Hôpital St. Louis , F-75010 Paris , France
- Department of Medical Biosciences, Building 6M, Umeå University , 901 85 Umeå , Sweden
- RECAMO, Masaryk Memorial Cancer Institute , Zluty kopec 7 , 65653 Brno , Czech Republic
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3
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Zheng AJL, Thermou A, Guixens Gallardo P, Malbert-Colas L, Daskalogianni C, Vaudiau N, Brohagen P, Granzhan A, Blondel M, Teulade-Fichou MP, Martins RP, Fahraeus R. The different activities of RNA G-quadruplex structures are controlled by flanking sequences. Life Sci Alliance 2021; 5:5/2/e202101232. [PMID: 34785537 PMCID: PMC8605322 DOI: 10.26508/lsa.202101232] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 11/08/2021] [Accepted: 11/08/2021] [Indexed: 12/17/2022] Open
Abstract
The role of G-quadruplex (G4) RNA structures is multifaceted and controversial. Here, we have used as a model the EBV-encoded EBNA1 and the Kaposi's sarcoma-associated herpesvirus (KSHV)-encoded LANA1 mRNAs. We have compared the G4s in these two messages in terms of nucleolin binding, nuclear mRNA retention, and mRNA translation inhibition and their effects on immune evasion. The G4s in the EBNA1 message are clustered in one repeat sequence and the G4 ligand PhenDH2 prevents all G4-associated activities. The RNA G4s in the LANA1 message take part in similar multiple mRNA functions but are spread throughout the message. The different G4 activities depend on flanking coding and non-coding sequences and, interestingly, can be separated individually. Together, the results illustrate the multifunctional, dynamic and context-dependent nature of G4 RNAs and highlight the possibility to develop ligands targeting specific RNA G4 functions. The data also suggest a common multifunctional repertoire of viral G4 RNA activities for immune evasion.
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Affiliation(s)
- Alice J-L Zheng
- Inserm UMRS1131, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St. Louis, Paris, France
| | - Aikaterini Thermou
- Inserm UMRS1131, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St. Louis, Paris, France.,ICCVS, University of Gdańsk, Science, Gdańsk, Poland
| | - Pedro Guixens Gallardo
- CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, Orsay, France.,CNRS UMR9187, INSERM U1196, Université Paris Sud, Université Paris-Saclay, Orsay, France
| | - Laurence Malbert-Colas
- Inserm UMRS1131, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St. Louis, Paris, France
| | - Chrysoula Daskalogianni
- Inserm UMRS1131, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St. Louis, Paris, France.,ICCVS, University of Gdańsk, Science, Gdańsk, Poland
| | - Nathan Vaudiau
- Inserm UMRS1131, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St. Louis, Paris, France
| | - Petter Brohagen
- Inserm UMRS1131, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St. Louis, Paris, France
| | - Anton Granzhan
- CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, Orsay, France.,CNRS UMR9187, INSERM U1196, Université Paris Sud, Université Paris-Saclay, Orsay, France
| | - Marc Blondel
- Inserm UMR1078, Université de Bretagne Occidentale (UBO), Etablissement Français du Sang (EFS) Bretagne, CHRU Brest, Brest, France
| | - Marie-Paule Teulade-Fichou
- CNRS UMR9187, INSERM U1196, Institut Curie, PSL Research University, Orsay, France.,CNRS UMR9187, INSERM U1196, Université Paris Sud, Université Paris-Saclay, Orsay, France
| | | | - Robin Fahraeus
- Inserm UMRS1131, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St. Louis, Paris, France .,RECAMO, Masaryk Memorial Cancer Institute, Brno, Czech Republic.,Department of Medical Biosciences, Umeå University, Umeå, Sweden.,ICCVS, University of Gdańsk, Science, Gdańsk, Poland
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4
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Gnanasundram SV, Malbert-Colas L, Chen S, Fusée L, Daskalogianni C, Muller P, Salomao N, Fåhraeus R. MDM2's dual mRNA binding domains co-ordinate its oncogenic and tumour suppressor activities. Nucleic Acids Res 2020; 48:6775-6787. [PMID: 32453417 PMCID: PMC7337897 DOI: 10.1093/nar/gkaa431] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 05/05/2020] [Accepted: 05/11/2020] [Indexed: 12/16/2022] Open
Abstract
Cell growth requires a high level of protein synthesis and oncogenic pathways stimulate cell proliferation and ribosome biogenesis. Less is known about how cells respond to dysfunctional mRNA translation and how this feeds back into growth regulatory pathways. The Epstein-Barr virus (EBV)-encoded EBNA1 causes mRNA translation stress in cis that activates PI3Kδ. This leads to the stabilization of MDM2, induces MDM2's binding to the E2F1 mRNA and promotes E2F1 translation. The MDM2 serine 166 regulates the interaction with the E2F1 mRNA and deletion of MDM2 C-terminal RING domain results in a constitutive E2F1 mRNA binding. Phosphorylation on serine 395 following DNA damage instead regulates p53 mRNA binding to its RING domain and prevents the E2F1 mRNA interaction. The p14Arf tumour suppressor binds MDM2 and in addition to preventing degradation of the p53 protein it also prevents the E2F1 mRNA interaction. The data illustrate how two MDM2 domains selectively bind specific mRNAs in response to cellular conditions to promote, or suppress, cell growth and how p14Arf coordinates MDM2's activity towards p53 and E2F1. The data also show how EBV via EBNA1-induced mRNA translation stress targets the E2F1 and the MDM2 - p53 pathway.
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Affiliation(s)
| | - Laurence Malbert-Colas
- Inserm UMRS1131, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St. Louis, F-75010 Paris, France
| | - Sa Chen
- Department of Medical Biosciences, Building 6M, Umeå University, 901 85 Umeå, Sweden
| | - Leila Fusée
- Inserm UMRS1131, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St. Louis, F-75010 Paris, France
| | - Chrysoula Daskalogianni
- Inserm UMRS1131, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St. Louis, F-75010 Paris, France
| | - Petr Muller
- RECAMO, Masaryk Memorial Cancer Institute, Zlutykopec 7, 65653 Brno, Czech Republic
| | - Norman Salomao
- Inserm UMRS1131, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St. Louis, F-75010 Paris, France
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5
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Martins RP, Malbert-Colas L, Lista MJ, Daskalogianni C, Apcher S, Pla M, Findakly S, Blondel M, Fåhraeus R. Nuclear processing of nascent transcripts determines synthesis of full-length proteins and antigenic peptides. Nucleic Acids Res 2019; 47:3086-3100. [PMID: 30624716 PMCID: PMC6451098 DOI: 10.1093/nar/gky1296] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 11/23/2018] [Accepted: 12/18/2018] [Indexed: 01/19/2023] Open
Abstract
Peptides presented on major histocompatibility (MHC) class I molecules form an essential part of the immune system's capacity to detect virus-infected or transformed cells. Earlier works have shown that pioneer translation peptides (PTPs) for the MHC class I pathway are as efficiently produced from introns as from exons, or from mRNAs targeted for the nonsense-mediated decay pathway. The production of PTPs is a target for viral immune evasion but the underlying molecular mechanisms that govern this non-canonical translation are unknown. Here, we have used different approaches to show how events taking place on the nascent transcript control the synthesis of PTPs and full-length proteins. By controlling the subcellular interaction between the G-quadruplex structure (G4) of a gly-ala encoding mRNA and nucleolin (NCL) and by interfering with mRNA maturation using multiple approaches, we demonstrate that antigenic peptides derive from a nuclear non-canonical translation event that is independently regulated from the synthesis of full-length proteins. Moreover, we show that G4 are exploited to control mRNA localization and translation by distinguishable mechanisms that are targets for viral immune evasion.
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Affiliation(s)
| | | | - María José Lista
- Université de Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France
| | - Chrysoula Daskalogianni
- Université Paris 7, Inserm, UMR 1162, Paris, France.,ICCVS, University of Gdańsk, Science, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Sebastien Apcher
- Institut Gustave Roussy, Université Paris Sud, UMR 1015, Villejuif, France
| | - Marika Pla
- Université Paris 7, IUH, Inserm, UMR-S-1131, Paris, France
| | | | - Marc Blondel
- Université de Brest, Inserm, EFS, UMR 1078, GGB, F-29200 Brest, France
| | - Robin Fåhraeus
- Université Paris 7, Inserm, UMR 1162, Paris, France.,ICCVS, University of Gdańsk, Science, ul. Wita Stwosza 63, 80-308 Gdańsk, Poland.,Department of Medical Biosciences, Umeå University, Umeå, Sweden.,RECAMO, Masaryk Memorial Cancer Institute, Zluty kopec 7, 656 53 Brno, Czech Republic
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6
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Tournillon AS, López I, Malbert-Colas L, Findakly S, Naski N, Olivares-Illana V, Karakostis K, Vojtesek B, Nylander K, Fåhraeus R. p53 binds the mdmx mRNA and controls its translation. Oncogene 2016; 36:723-730. [PMID: 27375027 DOI: 10.1038/onc.2016.236] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 04/22/2016] [Accepted: 06/03/2016] [Indexed: 12/22/2022]
Abstract
MDMX and MDM2 are two nonredundant essential regulators of p53 tumor suppressor activity. MDM2 controls p53 expression levels, whereas MDMX is predominantly a negative regulator of p53 trans-activity. The feedback loops between MDM2 and p53 are well studied and involve both negative and positive regulation on transcriptional, translational and post-translational levels but little is known on the regulatory pathways between p53 and MDMX. Here we show that overexpression of p53 suppresses mdmx mRNA translation in vitro and in cell-based assays. The core domain of p53 binds the 5' untranslated region (UTR) of the mdmx mRNA in a zinc-dependent manner that together with a trans-suppression domain located in p53 N-terminus controls MDMX synthesis. This interaction can be visualized in the nuclear and cytoplasmic compartment. Fusion of the mdmx 5'UTR to the ovalbumin open reading frame leads to suppression of ovalbumin synthesis. Interestingly, the transcription inactive p53 mutant R273H has a different RNA-binding profile compared with the wild-type p53 and differentiates the synthesis of MDMX isoforms. This study describes p53 as a trans-suppressor of the mdmx mRNA and adds a further level to the intricate feedback system that exist between p53 and its key regulatory factors and emphasizes the important role of mRNA translation control in regulating protein expression in the p53 pathway.
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Affiliation(s)
- A-S Tournillon
- Equipe Labellisée la Ligue Contre le Cancer, Institut National de la Santé et de la Recherche Médicale UMR1162, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St Louis, Paris, France
| | - I López
- Equipe Labellisée la Ligue Contre le Cancer, Institut National de la Santé et de la Recherche Médicale UMR1162, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St Louis, Paris, France
| | - L Malbert-Colas
- Equipe Labellisée la Ligue Contre le Cancer, Institut National de la Santé et de la Recherche Médicale UMR1162, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St Louis, Paris, France
| | - S Findakly
- Equipe Labellisée la Ligue Contre le Cancer, Institut National de la Santé et de la Recherche Médicale UMR1162, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St Louis, Paris, France
| | - N Naski
- Equipe Labellisée la Ligue Contre le Cancer, Institut National de la Santé et de la Recherche Médicale UMR1162, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St Louis, Paris, France
| | - V Olivares-Illana
- Instituto de Física, Universidad Autónoma de San Luis Potosí, San Luis Potosí, México
| | - K Karakostis
- Equipe Labellisée la Ligue Contre le Cancer, Institut National de la Santé et de la Recherche Médicale UMR1162, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St Louis, Paris, France
| | - B Vojtesek
- RECAMO, Masaryk Memorial Cancer Institute, Brno, Czech Republic
| | - K Nylander
- Department of Medical Biosciences, Umeå University, Umeå, Sweden
| | - R Fåhraeus
- Equipe Labellisée la Ligue Contre le Cancer, Institut National de la Santé et de la Recherche Médicale UMR1162, Institut de Génétique Moléculaire, Université Paris 7, Hôpital St Louis, Paris, France.,RECAMO, Masaryk Memorial Cancer Institute, Brno, Czech Republic.,Department of Medical Biosciences, Umeå University, Umeå, Sweden
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7
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Tournillon AS, López I, Malbert-Colas L, Naski N, Olivares-Illana V, Fåhraeus R. The alternative translated MDMX(p60) isoform regulates MDM2 activity. Cell Cycle 2015; 14:449-58. [PMID: 25659040 PMCID: PMC4615104 DOI: 10.4161/15384101.2014.977081] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Isoforms derived from alternative splicing, mRNA translation initiation or promoter usage extend the functional repertoire of the p53, p63 and p73 genes family and of their regulators MDM2 and MDMX. Here we show cap-independent translation of an N-terminal truncated isoform of hMDMX, hMDMXp60, which is initiated at the 7th AUG codon downstream of the initiation site for full length hMDMXFL at position +384. hMDMXp60 lacks the p53 binding motif but retains the RING domain and interacts with hMDM2 and hMDMXFL. hMDMXp60 shows higher affinity for hMDM2, as compared to hMDMXFL. In vitro data reveal a positive cooperative interaction between hMDMXp60 and hMDM2 and in cellulo data show that low levels of hMDMXp60 promote degradation of hMDM2 whereas higher levels stabilize hMDM2 and prevent hMDM2-mediated degradation of hMDMXFL. These results describe a novel alternatively translated hMDMX isoform that exhibits unique regulatory activity toward hMDM2 autoubiquitination. The data illustrate how the N-terminus of hMDMX regulates its C-terminal RING domain and the hMDM2 activity.
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Affiliation(s)
- Anne-Sophie Tournillon
- a Cibles Thérapeutiques, Equipe Labellisée la Ligue Contre le Cancer, Institut National de la Santé et de la Recherche Médicale UMR1162; Institut de Génétique Moléculaire , Université Paris 7 ; Hôpital St. Louis; Paris , France
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8
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9
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Malbert-Colas L, Ponnuswamy A, Olivares-Illana V, Tournillon AS, Naski N, Fåhraeus R. HDMX Folds the Nascent p53 mRNA following Activation by the ATM Kinase. Mol Cell 2014; 54:500-11. [DOI: 10.1016/j.molcel.2014.02.035] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 10/21/2013] [Accepted: 02/26/2014] [Indexed: 10/25/2022]
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10
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Gajjar M, Candeias MM, Malbert-Colas L, Mazars A, Fujita J, Olivares-Illana V, Fåhraeus R. The p53 mRNA-Mdm2 interaction controls Mdm2 nuclear trafficking and is required for p53 activation following DNA damage. Cancer Cell 2012; 21:25-35. [PMID: 22264786 DOI: 10.1016/j.ccr.2011.11.016] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2011] [Revised: 09/15/2011] [Accepted: 11/23/2011] [Indexed: 10/14/2022]
Abstract
The ATM kinase and p53 are key tumor suppressor factors that control the genotoxic stress response pathway. The ATM substrate Mdm2 controls p53 activity by either targeting p53 for degradation or promoting its synthesis by binding the p53 mRNA. The physiological role and regulation of Mdm2's dual function toward p53 is not known. Here we show that ATM-dependent phosphorylation of Mdm2 at Ser395 is required for the p53 mRNA-Mdm2 interaction. This event also promotes SUMO-conjugation of Mdm2 and its nucleoli accumulation. Interfering with the p53 mRNA-Mdm2 interaction prevents p53 stabilization and activation following DNA damage. These results demonstrate how ATM activity switches Mdm2 from a negative to a positive regulator of p53 via the p53 mRNA.
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Affiliation(s)
- Madhavsai Gajjar
- Cibles Therapeutiques, INSERM Unité, Institut de Génétique Moléculaire, Université Paris, IUH Hôpital St. Louis, Paris, France
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11
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Candeias MM, Malbert-Colas L, Powell DJ, Daskalogianni C, Maslon MM, Naski N, Bourougaa K, Calvo F, Fåhraeus R. P53 mRNA controls p53 activity by managing Mdm2 functions. Nat Cell Biol 2009; 10:1098-105. [PMID: 19160491 DOI: 10.1038/ncb1770] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The E3 ubiquitin ligase Mdm2 is a focal regulator of p53 tumour suppressor activity. It binds p53, promoting its polyubiquitination and degradation, and also controls p53 synthesis. However, it is not known how this dual function of Mdm2 on p53 synthesis and degradation is achieved. Here we show that the p53 mRNA region encoding the Mdm2-binding site interacts directly with the RING domain of Mdm2. This impairs the E3 ligase activity of Mdm2 and promotes p53 mRNA translation. We also show that introduction of cancer-derived single silent point-mutations in the p53 mRNA weakens its binding to Mdm2 and results in reduced p53 activity. These data are consistent with a mechanism by which changes in silent nucleotides can affect the function of the encoded protein, and indicate that Mdm2-mediated control of p53 synthesis and degradation has evolved in the p53 mRNA sequence and its encoded amino acids.
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Affiliation(s)
- Marco M Candeias
- Inserm U716, Pharmacologie Expérimentale, Institut Génétique Moléculaire, Hôpital St Louis and Université Paris 7, 27 rue Juliette Dodu, 75010 Paris, France
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Bouvry D, Planès C, Malbert-Colas L, Escabasse V, Clerici C. Hypoxia-Induced Cytoskeleton Disruption in Alveolar Epithelial Cells. Am J Respir Cell Mol Biol 2006; 35:519-27. [PMID: 16741163 DOI: 10.1165/rcmb.2005-0478oc] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Alveolar hypoxia, a common feature of many respiratory disorders, has been previously reported to induce functional changes, particularly a decrease of transepithelial Na and fluid transport. In polarized epithelia, cytoskeleton plays a regulatory role in transcellular and paracellular transport of ions and fluid. We hypothesized that exposure to hypoxia could damage cytoskeleton organization, which in turn, may adversely affect ion and fluid transport. Primary rat alveolar epithelial cells (AEC) were exposed to either mild (3% O(2)) or severe (0.5% O(2)) hypoxia for 18 h or to normoxia (21% O(2)). First, mild and severe hypoxia induced a disorganization of actin, a major protein of the cytoskeleton, reflected by disruption of F-actin filaments. Second, alpha-spectrin, an apical cytoskeleton protein, which binds to actin cytoskeleton and Na transport proteins, was cleaved by hypoxia. Pretreatment of AEC by a caspase inhibitor (z-VAD-fmk; 90 microM) blunted hypoxia-induced spectrin cleavage as well as hypoxia-induced decrease in surface membrane alpha-ENaC and concomitantly induced a partial recovery of hypoxia-induced decrease of amiloride-sensitive Na transport at 3% O(2). Finally, tight junctions (TJs) proteins, which are linked to actin and are a determinant of paracellular permeability, were altered by mild and severe hypoxia: hypoxia induced a mislocalization of occludin from the TJ to cytoplasm and a decrease in zonula occludens-1 protein level. These modifications were associated with modest changes in paracellular permeability at 0.5% O(2,) as assessed by small 4-kD dextran flux and transepithelial resistance measurements. Together, these findings indicate that hypoxia disrupted cytoskeleton and TJ organization in AEC and may participate, at least in part, to hypoxia-induced decrease in Na transport.
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Affiliation(s)
- Diane Bouvry
- INSERM U773 Centre de Recherche Biomédicale Bichat-Beaujon (CRB3), Université Paris 7 Denis Diderot, UFR de Médecine, Site Bichat, France
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Abstract
A fine regulation of the amiloride-sensitive Epithelial Sodium Channel (ENaC), made of alpha, beta and gamma subunits, is crucial for maintenance of Na+ balance and blood pressure. Both beta- and gamma-ENaC participate in negative regulation by interacting with Nedd4-2, an E3 ubiquitin-ligase. Disruption of this interaction results in increased ENaC activity (Liddle syndrome). By two-hybrid screenings, we identified new potential partners of alpha-ENaC: WWP1 (E3 ubiquitin-ligase protein), UBC9 and TSG101 (E2 ubiquitin/SUMO-conjugating enzymes) and confirmed these interactions in GST pull-down assays. All these partners are implicated in protein trafficking and could be involved in the regulation of ENaC activity.
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Affiliation(s)
- Laurence Malbert-Colas
- Inserm U409 and IFR02, Institut Claude-Bernard, physiologie et pathologie, faculté de médecine Xavier-Bichat, BP 416, 75780 Paris, France
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Fouladkou F, Alikhani-Koopaei R, Vogt B, Flores SY, Malbert-Colas L, Lecomte MC, Loffing J, Frey FJ, Frey BM, Staub O. A naturally occurring human Nedd4-2 variant displays impaired ENaC regulation in Xenopus laevis oocytes. Am J Physiol Renal Physiol 2004; 287:F550-61. [PMID: 15140763 DOI: 10.1152/ajprenal.00353.2003] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The epithelial Na(+) channel (ENaC) is regulated by the ubiquitin-protein ligase Nedd4-2 via interaction with ENaC PY-motifs. These PY-motifs are mutated/deleted in Liddle's syndrome, resulting in elevated Na(+) reabsorption and hypertension explained partly by impaired ENaC-Nedd4-2 interaction. We hypothesized that Nedd4-2 is a susceptibility gene for hypertension and screened 856 renal patients and healthy controls for mutations in a subset of exons of the human Nedd4-2 gene that are relevant for ENaC regulation by PCR/single-strand conformational polymorphism. Several variants were identified, and one nonsynonymous mutation (Nedd4-2-P355L) was further characterized. This mutation next to the 3' donor site of exon 15 does not affect in vitro splicing of Nedd4-2 mRNA. However, in the Xenopus oocyte expression system, Nedd4-2-P355L-dependent ENaC inhibition was weaker compared with the wild type (Nedd4-2-WT), and this difference depended on the presence of intact PY-motifs on ENaC. This could not be explained by the amount of wild type or mutant Nedd4-2 coimmunoprecipitating with ENaC. When the phosphorylation level of human Nedd4-2 Ser(448) (known to be phosphorylated by the Sgk1 kinase) was determined with a specific anti-pSer(448) antibody, we observed stronger basal phosphorylation of Nedd4-2-P355L. Both the phosphorylation level and the accompanying amiloride-sensitive Na(+) currents could be further enhanced to approximately the same levels by coexpressing Sgk1. In addition, the role of the two other putative Sgk1 phosphorylation sites (S342 and T367) appears also to be affected by the P355L mutation. The differential phosphorylation status between wild-type and mutant Nedd4-2 provides an explanation for the different potential to inhibit ENaC activity.
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Affiliation(s)
- Fatemeh Fouladkou
- Division of Nephrology and Hypertension, Department of Clinical Research, University of Bern, CH-3010 Bern
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Malbert-Colas L, Fay M, Cluzeaud F, Blot-Chabaud M, Farman N, Dhermy D, Lecomte MC. Differential expression and localisation of WWP1, a Nedd4-like protein, in epithelia. Pflugers Arch 2003; 447:35-43. [PMID: 12908109 DOI: 10.1007/s00424-003-1152-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2003] [Accepted: 07/17/2003] [Indexed: 11/27/2022]
Abstract
Ubiquitination of proteins such as ion transporters appears to be an important process in the regulation of their membrane expression. Recently, using two-hybrid screening, we have selected a potential partner for the alpha-subunit of the amiloride-sensitive epithelial sodium channel (ENaC): the WWP1 protein, a ubiquitin ligase belonging to the Nedd4 family. To establish whether WWP1 is co-expressed with ENaC, we employed in situ hybridisation, immunohistochemistry and Western blotting to determine the expression of WWP1 in various tissues and cell lines, including those known to express ENaC. As expected, WWP1 was expressed, like ENaC, in the bronchiolar epithelium. However it was also present in the proximal colon and the proximal part of the nephron (where ENaC is not expressed) and absent in the distal parts of the nephron (where ENaC is expressed abundantly). These results suggest that other channels or transport proteins, containing specific domains, such as PY motifs, could be the targets for regulation by WWP1.
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Nicolas G, Fournier CM, Galand C, Malbert-Colas L, Bournier O, Kroviarski Y, Bourgeois M, Camonis JH, Dhermy D, Grandchamp B, Lecomte MC. Tyrosine phosphorylation regulates alpha II spectrin cleavage by calpain. Mol Cell Biol 2002; 22:3527-36. [PMID: 11971983 PMCID: PMC133798 DOI: 10.1128/mcb.22.10.3527-3536.2002] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spectrins, components of the membrane skeleton, are implicated in various cellular functions. Understanding the diversity of these functions requires better characterization of the interacting domains of spectrins, such as the SH3 domain. Yeast two-hybrid screening of a kidney cDNA library revealed that the SH3 domain of alpha II-spectrin binds specifically isoform A of low-molecular-weight phosphotyrosine phosphatase (LMW-PTP). The alpha II-spectrin SH3 domain does not interact with LMW-PTP B or C nor does LMW-PTP A interact with the alpha I-spectrin SH3 domain. The interaction of spectrin with LMW-PTP A led us to look for a tyrosine-phosphorylated residue in alpha II-spectrin. Western blotting showed that alpha II-spectrin is tyrosine phosphorylated in vivo. Using mutagenesis on recombinant peptides, we identified the residue Y1176 located in the calpain cleavage site of alpha II-spectrin, near the SH3 domain, as an in vitro substrate for Src kinase and LMW-PTP A. This Y1176 residue is also an in vivo target for kinases and phosphatases in COS cells. Phosphorylation of this residue decreases spectrin sensitivity to calpain in vitro. Similarly, the presence of phosphatase inhibitors in cell culture is associated with the absence of spectrin cleavage products. This suggests that the Y1176 phosphorylation state could modulate spectrin cleavage by calpain and may play an important role during membrane skeleton remodeling.
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Affiliation(s)
- Gaël Nicolas
- INSERM U409, Faculté de Médecine Xavier Bichat-Association Claude Bernard, Paris, France
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Lecomte MC, Nicolas G, Fournier C, Galand C, Malbert-Colas L, Bournier O, Dhermy D, Grandchamps B. Interaction of Spectrin with the Low Molecular Weight Phosphotyrosine Phosphatese (LMW-PTP). Cell Mol Biol Lett 2001; 6:216. [PMID: 11544668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
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