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Ashour K, Sali S, Aldoukhi AH, Hall D, Mubaid S, Busque S, Lian XJ, Gagné JP, Khattak S, Di Marco S, Poirier GG, Gallouzi IE. pADP-ribosylation regulates the cytoplasmic localization, cleavage, and pro-apoptotic function of HuR. Life Sci Alliance 2024; 7:e202302316. [PMID: 38538092 PMCID: PMC10972696 DOI: 10.26508/lsa.202302316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2023] [Revised: 03/19/2024] [Accepted: 03/20/2024] [Indexed: 04/05/2024] Open
Abstract
HuR (ElavL1) is one of the main post-transcriptional regulators that determines cell fate. Although the role of HuR in apoptosis is well established, the post-translational modifications that govern this function remain elusive. In this study, we show that PARP1/2-mediated poly(ADP)-ribosylation (PARylation) is instrumental in the pro-apoptotic function of HuR. During apoptosis, a substantial reduction in HuR PARylation is observed. This results in the cytoplasmic accumulation and the cleavage of HuR, both of which are essential events for apoptosis. These effects are mediated by a pADP-ribose-binding motif within the HuR-HNS region (HuR PAR-binding site). Under normal conditions, the association of the HuR PAR-binding site with pADP-ribose is responsible for the nuclear retention of HuR. Mutations within this motif prevent the binding of HuR to its import factor TRN2, leading to its cytoplasmic accumulation and cleavage. Collectively, our findings underscore the role of PARylation in controlling the pro-apoptotic function of HuR, offering insight into the mechanism by which PARP1/2 enzymes regulate cell fate and adaptation to various assaults.
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Affiliation(s)
- Kholoud Ashour
- Department of Biochemistry, McGill University, Montreal, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, Canada
- Faculty of Applied Medical Sciences, Medical Laboratory Technology, Taibah University, Medina, Saudi Arabia
| | - Sujitha Sali
- https://ror.org/01q3tbs38 KAUST Smart-Health Initiative (KSHI) and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
| | - Ali H Aldoukhi
- https://ror.org/01q3tbs38 KAUST Smart-Health Initiative (KSHI) and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
| | - Derek Hall
- Department of Biochemistry, McGill University, Montreal, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, Canada
| | - Souad Mubaid
- Department of Biochemistry, McGill University, Montreal, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, Canada
| | - Sandrine Busque
- Department of Biochemistry, McGill University, Montreal, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, Canada
| | - Xian Jin Lian
- Department of Biochemistry, McGill University, Montreal, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, Canada
| | - Jean-Philippe Gagné
- Centre de recherche du CHU de Québec-Pavillon CHUL, Faculté de Médecine, Université Laval, Québec, Canada
| | - Shahryar Khattak
- https://ror.org/01q3tbs38 KAUST Smart-Health Initiative (KSHI) and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
| | - Sergio Di Marco
- https://ror.org/01q3tbs38 KAUST Smart-Health Initiative (KSHI) and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
- Department of Biochemistry, McGill University, Montreal, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, Canada
| | - Guy G Poirier
- Centre de recherche du CHU de Québec-Pavillon CHUL, Faculté de Médecine, Université Laval, Québec, Canada
| | - Imed-Eddine Gallouzi
- https://ror.org/01q3tbs38 KAUST Smart-Health Initiative (KSHI) and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
- Department of Biochemistry, McGill University, Montreal, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, Montreal, Canada
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Mubaid S, Sanchez BJ, Algehani RA, Skopenkova V, Adjibade P, Hall DT, Busque S, Lian XJ, Ashour K, Tremblay AMK, Carlile G, Gagné JP, Diaz-Gaxiola A, Khattak S, Di Marco S, Thomas DY, Poirier GG, Gallouzi IE. Tankyrase-1 regulates RBP-mediated mRNA turnover to promote muscle fiber formation. Nucleic Acids Res 2024; 52:4002-4020. [PMID: 38321934 DOI: 10.1093/nar/gkae059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 01/19/2024] [Indexed: 02/08/2024] Open
Abstract
Poly(ADP-ribosylation) (PARylation) is a post-translational modification mediated by a subset of ADP-ribosyl transferases (ARTs). Although PARylation-inhibition based therapies are considered as an avenue to combat debilitating diseases such as cancer and myopathies, the role of this modification in physiological processes such as cell differentiation remains unclear. Here, we show that Tankyrase1 (TNKS1), a PARylating ART, plays a major role in myogenesis, a vital process known to drive muscle fiber formation and regeneration. Although all bona fide PARPs are expressed in muscle cells, experiments using siRNA-mediated knockdown or pharmacological inhibition show that TNKS1 is the enzyme responsible of catalyzing PARylation during myogenesis. Via this activity, TNKS1 controls the turnover of mRNAs encoding myogenic regulatory factors such as nucleophosmin (NPM) and myogenin. TNKS1 mediates these effects by targeting RNA-binding proteins such as Human Antigen R (HuR). HuR harbors a conserved TNKS-binding motif (TBM), the mutation of which not only prevents the association of HuR with TNKS1 and its PARylation, but also precludes HuR from regulating the turnover of NPM and myogenin mRNAs as well as from promoting myogenesis. Therefore, our data uncover a new role for TNKS1 as a key modulator of RBP-mediated post-transcriptional events required for vital processes such as myogenesis.
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Affiliation(s)
- Souad Mubaid
- Dept. of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, 1160 Pine Avenue, Montreal, QC H3A 1A3, Canada
| | - Brenda Janice Sanchez
- KAUST Smart-Health Initiative (KSHI) and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
| | - Rinad A Algehani
- KAUST Smart-Health Initiative (KSHI) and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
| | - Viktoriia Skopenkova
- KAUST Smart-Health Initiative (KSHI) and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
| | - Pauline Adjibade
- Dept. of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, 1160 Pine Avenue, Montreal, QC H3A 1A3, Canada
| | - Derek T Hall
- Dept. of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, 1160 Pine Avenue, Montreal, QC H3A 1A3, Canada
| | - Sandrine Busque
- Dept. of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, 1160 Pine Avenue, Montreal, QC H3A 1A3, Canada
| | - Xian Jin Lian
- Dept. of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, 1160 Pine Avenue, Montreal, QC H3A 1A3, Canada
| | - Kholoud Ashour
- Dept. of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, 1160 Pine Avenue, Montreal, QC H3A 1A3, Canada
| | - Anne-Marie K Tremblay
- Dept. of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, 1160 Pine Avenue, Montreal, QC H3A 1A3, Canada
| | - Graeme Carlile
- Dept. of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada
| | - Jean-Philippe Gagné
- Centre de recherche du CHU de Québec-Pavillon CHUL, Faculté de Médecine, Université Laval, Québec G1V 4G2, Canada
| | - Andrea Diaz-Gaxiola
- KAUST Smart-Health Initiative (KSHI) and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
| | - Shahryar Khattak
- KAUST Smart-Health Initiative (KSHI) and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
| | - Sergio Di Marco
- KAUST Smart-Health Initiative (KSHI) and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
- Dept. of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, 1160 Pine Avenue, Montreal, QC H3A 1A3, Canada
| | - David Y Thomas
- Dept. of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada
| | - Guy G Poirier
- Centre de recherche du CHU de Québec-Pavillon CHUL, Faculté de Médecine, Université Laval, Québec G1V 4G2, Canada
| | - Imed-Eddine Gallouzi
- KAUST Smart-Health Initiative (KSHI) and Biological and Environmental Science and Engineering (BESE) Division, King Abdullah University of Science and Technology (KAUST), Jeddah, Saudi Arabia
- Dept. of Biochemistry, McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6, Canada
- Rosalind & Morris Goodman Cancer Institute, McGill University, 1160 Pine Avenue, Montreal, QC H3A 1A3, Canada
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Omer A, Patel D, Moran JL, Lian XJ, Di Marco S, Gallouzi IE. Autophagy and heat-shock response impair stress granule assembly during cellular senescence. Mech Ageing Dev 2020; 192:111382. [PMID: 33049246 DOI: 10.1016/j.mad.2020.111382] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/21/2020] [Accepted: 10/05/2020] [Indexed: 01/08/2023]
Abstract
Stress granules (SGs) are membraneless organelles formed in response to insult. These granules are related to pathological granules found in age-related neurogenerative diseases such as Parkinson's and Alzheimer's. Previously, we demonstrated that senescent cells, which accumulate with age, exposed to chronic oxidative stress, are unable to form SGs. Here, we show that the senescent cells' inability to form SGs correlates with an upregulation in both the heat-shock response and autophagy pathways, both of which are well-established promoters of SG disassembly. Our data also reveals that the knockdown of HSP70 and ATG5, important components of the heat-shock response and autophagy pathways, respectively, restores the number of SGs formed in senescent cells exposed to chronic oxidative stress. Surprisingly, under these conditions, the depletion of HSP70 or ATG5 did not affect the clearance of these SGs during their recovery from chronic stress. These data reveal that senescent cells possess a unique heat-shock and autophagy-dependent ability to impair the formation of SGs in response to chronic stress, thereby expanding the existing understanding of SG dynamics in senescent cells and their potential contribution to age-related neurodegenerative diseases.
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Affiliation(s)
- Amr Omer
- McGill University, Department of Biochemistry, Rosalind and Morris Goodman Cancer Centre, Montreal, Quebec, Canada.
| | - Devang Patel
- McGill University, Department of Biochemistry, Rosalind and Morris Goodman Cancer Centre, Montreal, Quebec, Canada
| | - Julian Lucas Moran
- McGill University, Department of Biochemistry, Rosalind and Morris Goodman Cancer Centre, Montreal, Quebec, Canada
| | - Xian Jin Lian
- McGill University, Department of Biochemistry, Rosalind and Morris Goodman Cancer Centre, Montreal, Quebec, Canada
| | - Sergio Di Marco
- McGill University, Department of Biochemistry, Rosalind and Morris Goodman Cancer Centre, Montreal, Quebec, Canada
| | - Imed-Eddine Gallouzi
- McGill University, Department of Biochemistry, Rosalind and Morris Goodman Cancer Centre, Montreal, Quebec, Canada.
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Omer A, Patel D, Lian XJ, Sadek J, Di Marco S, Pause A, Gorospe M, Gallouzi IE. Stress granules counteract senescence by sequestration of PAI-1. EMBO Rep 2018; 19:embr.201744722. [PMID: 29592859 PMCID: PMC5934773 DOI: 10.15252/embr.201744722] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Revised: 02/23/2018] [Accepted: 03/06/2018] [Indexed: 12/27/2022] Open
Abstract
Cellular senescence is a physiological response by which an organism halts the proliferation of potentially harmful and damaged cells. However, the accumulation of senescent cells over time can become deleterious leading to diseases and physiological decline. Our data reveal a novel interplay between senescence and the stress response that affects both the progression of senescence and the behavior of senescent cells. We show that constitutive exposure to stress induces the formation of stress granules (SGs) in proliferative and presenescent cells, but not in fully senescent cells. Stress granule assembly alone is sufficient to decrease the number of senescent cells without affecting the expression of bona fide senescence markers. SG‐mediated inhibition of senescence is associated with the recruitment of the plasminogen activator inhibitor‐1 (PAI‐1), a known promoter of senescence, to these entities. PAI‐1 localization to SGs increases the translocation of cyclin D1 to the nucleus, promotes RB phosphorylation, and maintains a proliferative, non‐senescent state. Together, our data indicate that SGs may be targets of intervention to modulate senescence in order to impair or prevent its deleterious effects.
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Affiliation(s)
- Amr Omer
- Department of Biochemistry, Rosalind and Morris Goodman Cancer Centre, McGill University, Montreal, QC, Canada
| | - Devang Patel
- Department of Biochemistry, Rosalind and Morris Goodman Cancer Centre, McGill University, Montreal, QC, Canada
| | - Xian Jin Lian
- Department of Biochemistry, Rosalind and Morris Goodman Cancer Centre, McGill University, Montreal, QC, Canada
| | - Jason Sadek
- Department of Biochemistry, Rosalind and Morris Goodman Cancer Centre, McGill University, Montreal, QC, Canada
| | - Sergio Di Marco
- Department of Biochemistry, Rosalind and Morris Goodman Cancer Centre, McGill University, Montreal, QC, Canada
| | - Arnim Pause
- Department of Biochemistry, Rosalind and Morris Goodman Cancer Centre, McGill University, Montreal, QC, Canada
| | - Myriam Gorospe
- Laboratory of Genetics and Genomics, National Institute on Aging-Intramural Research Program, NIH, Baltimore, MD, USA
| | - Imed Eddine Gallouzi
- Department of Biochemistry, Rosalind and Morris Goodman Cancer Centre, McGill University, Montreal, QC, Canada .,Life Sciences Division, Hamad Bin Khalifa University (HBKU), Education City, Doha, Qatar
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Cammas A, Sanchez BJ, Lian XJ, Dormoy-Raclet V, van der Giessen K, López de Silanes I, Ma J, Wilusz C, Richardson J, Gorospe M, Millevoi S, Giovarelli M, Gherzi R, Di Marco S, Gallouzi IE. Destabilization of nucleophosmin mRNA by the HuR/KSRP complex is required for muscle fibre formation. Nat Commun 2014; 5:4190. [PMID: 24969639 PMCID: PMC4074165 DOI: 10.1038/ncomms5190] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [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: 03/25/2014] [Accepted: 05/21/2014] [Indexed: 01/03/2023] Open
Abstract
HuR promotes myogenesis by stabilizing the MyoD, myogenin and p21 mRNAs during the fusion of muscle cells to form myotubes. Here we show that HuR, via a novel mRNA destabilizing activity, promotes the early steps of myogenesis by reducing the expression of the cell cycle promoter nucleophosmin (NPM). Depletion of HuR stabilizes the NPM mRNA, increases NPM protein levels and inhibits myogenesis, while its overexpression elicits the opposite effects. NPM mRNA destabilization involves the association of HuR with the decay factor KSRP as well as the ribonuclease PARN and the exosome. The C terminus of HuR mediates the formation of the HuR-KSRP complex and is sufficient for maintaining a low level of the NPM mRNA as well as promoting the commitment of muscle cells to myogenesis. We therefore propose a model whereby the downregulation of the NPM mRNA, mediated by HuR, KSRP and its associated ribonucleases, is required for proper myogenesis.
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Affiliation(s)
- Anne Cammas
- 1] Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6 [2] INSERM, UMR 1037, Centre de Recherche en Cancérologie de Toulouse, 31432 Toulouse, France
| | - Brenda Janice Sanchez
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Xian Jin Lian
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Virginie Dormoy-Raclet
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Kate van der Giessen
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Isabel López de Silanes
- Spanish National Cancer Research Centre (CNIO) Telomeres and Telomerase Group, Molecular Oncology Program, C/ Melchor Fernández Almagro, 3, 28029 Madrid, Spain
| | - Jennifer Ma
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Carol Wilusz
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado 80523-1682, USA
| | - John Richardson
- Department of Neurology and Neurosurgery, McGill University, 3801 University Street, Montreal, Quebec, Canada H3A2B4
| | - Myriam Gorospe
- National Institute on Aging, National Institutes of Health, Biomedical Research Center, Room 06C226, 251 Bayview Boulevard, Suite 100, Baltimore, Maryland 21224-6825, USA
| | - Stefania Millevoi
- INSERM, UMR 1037, Centre de Recherche en Cancérologie de Toulouse, 31432 Toulouse, France
| | - Matteo Giovarelli
- Istituto Nazionale Ricerca sul Cancro (IST), Laboratory of Gene Expression Regulation, c/o CBA Building A3, Room 30, Largo R. Benzi, 10, 16132 Genova, Italy
| | - Roberto Gherzi
- Istituto Nazionale Ricerca sul Cancro (IST), Laboratory of Gene Expression Regulation, c/o CBA Building A3, Room 30, Largo R. Benzi, 10, 16132 Genova, Italy
| | - Sergio Di Marco
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
| | - Imed-Eddine Gallouzi
- Department of Biochemistry, Goodman Cancer Center, McGill University, McIntyre Building Room 915B, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada H3G 1Y6
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Di Marco S, Cammas A, Lian XJ, Kovacs EN, Ma JF, Hall DT, Mazroui R, Richardson J, Pelletier J, Gallouzi IE. The translation inhibitor pateamine A prevents cachexia-induced muscle wasting in mice. Nat Commun 2012; 3:896. [PMID: 22692539 PMCID: PMC3621420 DOI: 10.1038/ncomms1899] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [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: 11/04/2011] [Accepted: 05/09/2012] [Indexed: 12/16/2022] Open
Abstract
Cachexia, or muscle-wasting syndrome, is one of the major causes of death in patients affected by diseases such as cancer, AIDS and sepsis. However, no effective anti-cachectic treatment is currently available. Here we show that a low dose of pateamine A, an inhibitor of translation initiation, prevents muscle wasting caused by the cytokines interferon γ and tumour necrosis factor α or by C26-adenocarcinoma tumours. Surprisingly, although high doses of pateamine A abrogate general translation, low doses selectively inhibit the expression of pro-cachectic factors such as inducible nitric oxide synthase. This selectivity depends on the 5'UTR of inducible nitric oxide synthase messenger RNA (mRNA) that, unlike the 5'UTR of MyoD mRNA, promotes the recruitment of inducible nitric oxide synthase mRNA to stress granules, where its translation is repressed. Collectively, our data provide a proof of principle that nontoxic doses of compounds such as pateamine A could be used as novel drugs to combat cachexia-induced muscle wasting.
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Affiliation(s)
- Sergio Di Marco
- Department of Biochemistry, Rosalind and Morris Goodman Cancer Center, McGill University, 3655 Promenade Sir William Osler, Montreal, Quebec, Canada
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Lian XJ, Gallouzi IE. Oxidative Stress Increases the Number of Stress Granules in Senescent Cells and Triggers a Rapid Decrease in p21waf1/cip1 Translation. J Biol Chem 2009; 284:8877-87. [PMID: 19176530 DOI: 10.1074/jbc.m806372200] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Very little is known as to how the accumulation of senescent cells during aging may affect our ability to cope with various stresses. Here we show that the assembly of stress granules (SGs) is part of the early events used by senescent cells to respond to certain stresses. Although SGs can form in response to stress during senescence activation, their number significantly increases once the cells are fully senescent. This increase correlates with a rapid decrease in the expression levels of the cyclin kinase inhibitor p21, an important activator of senescence. Throughout stress, p21 mRNA is stabilized and localizes to SGs, but only during late senescence does this localization interferes with its translation. Additionally, we observed that when the stress is relieved, senescent cells produce lower levels of p21 protein, which correlates with a small delay in SG disassembly. Therefore, our data suggest that SG formation and the reduction in p21 protein levels represent two main events by which senescent cells respond to stress.
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Affiliation(s)
- Xian Jin Lian
- Biochemistry Department, McGill University, Montreal H3G 1Y6, Canada
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