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Koutsougianni F, Alexopoulou D, Uvez A, Lamprianidou A, Sereti E, Tsimplouli C, Ilkay Armutak E, Dimas K. P90 ribosomal S6 kinases: A bona fide target for novel targeted anticancer therapies? Biochem Pharmacol 2023; 210:115488. [PMID: 36889445 DOI: 10.1016/j.bcp.2023.115488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Revised: 02/28/2023] [Accepted: 03/01/2023] [Indexed: 03/08/2023]
Abstract
The 90 kDa ribosomal S6 kinase (RSK) family of proteins is a group of highly conserved Ser/Thr kinases. They are downstream effectors of the Ras/ERK/MAPK signaling cascade. ERK1/2 activation directly results in the phosphorylation of RSKs, which further, through interaction with a variety of different downstream substrates, activate various signaling events. In this context, they have been shown to mediate diverse cellular processes like cell survival, growth, proliferation, EMT, invasion, and metastasis. Interestingly, increased expression of RSKs has also been demonstrated in various cancers, such as breast, prostate, and lung cancer. This review aims to present the most recent advances in the field of RSK signaling that have occurred, such as biological insights, function, and mechanisms associated with carcinogenesis. We additionally present and discuss the recent advances but also the limitations in the development of pharmacological inhibitors of RSKs, in the context of the use of these kinases as putative, more efficient targets for novel anticancer therapeutic approaches.
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Affiliation(s)
- Fani Koutsougianni
- Department of Pharmacology, Faculty of Medicine, Health Sciences School, University of Thessaly, Larissa, Greece
| | - Dimitra Alexopoulou
- Department of Pharmacology, Faculty of Medicine, Health Sciences School, University of Thessaly, Larissa, Greece
| | - Ayca Uvez
- Department of Histology and Embryology, Faculty of Veterinary Medicine, Istanbul University-Cerrahpasa, 34500 Istanbul, Turkey
| | - Andromachi Lamprianidou
- Department of Pharmacology, Faculty of Medicine, Health Sciences School, University of Thessaly, Larissa, Greece
| | - Evangelia Sereti
- Dept of Translational Medicine, Medical Faculty, Lund University and Center for Molecular Pathology, Skäne University Hospital, Jan Waldenströms gata 59, SE 205 02 Malmö, Sweden
| | - Chrisiida Tsimplouli
- Department of Pharmacology, Faculty of Medicine, Health Sciences School, University of Thessaly, Larissa, Greece
| | - Elif Ilkay Armutak
- Department of Histology and Embryology, Faculty of Veterinary Medicine, Istanbul University-Cerrahpasa, 34500 Istanbul, Turkey
| | - Konstantinos Dimas
- Department of Pharmacology, Faculty of Medicine, Health Sciences School, University of Thessaly, Larissa, Greece.
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Sun Y, Tang L, Wu C, Wang J, Wang C. RSK inhibitors as potential anticancer agents: Discovery, optimization, and challenges. Eur J Med Chem 2023; 251:115229. [PMID: 36898330 DOI: 10.1016/j.ejmech.2023.115229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/19/2023] [Accepted: 02/20/2023] [Indexed: 02/27/2023]
Abstract
Ribosomal S6 kinase (RSK) family is a group of serine/threonine kinases, including four isoforms (RSK1/2/3/4). As a downstream effector of the Ras-mitogen-activated protein kinase (Ras-MAPK) pathway, RSK participates in many physiological activities such as cell growth, proliferation, and migration, and is intimately involved in tumor occurrence and development. As a result, it is recognized as a potential target for anti-cancer and anti-resistance therapies. There have been several RSK inhibitors discovered or designed in recent decades, but only two have entered clinical trials. Low specificity, low selectivity, and poor pharmacokinetic properties in vivo limit their clinical translation. Published studies performed structure optimization by increasing interaction with RSK, avoiding hydrolysis of pharmacophores, eliminating chirality, adapting to binding site shape, and becoming prodrugs. Besides enhancing efficacy, the focus of further design will move towards selectivity since there are functional differences among RSK isoforms. This review summarized the types of cancers associated with RSK, along with the structural characteristics and optimization process of the reported RSK inhibitors. Furthermore, we addressed the importance of RSK inhibitors' selectivity and discussed future drug development directions. This review is expected to shed light on the emergence of RSK inhibitors with high potency, specificity, and selectivity.
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Affiliation(s)
- Ying Sun
- Department of Respiratory and Critical Care Medicine, Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; State Key Laboratory of Biotherapy and Cancer Center, Department of Respiratory and Critical Care Medicine, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; Precision Medicine Key Laboratory of Sichuan Province & Precision Medicine Research Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Lichao Tang
- Department of Biomedical Engineering, McCormick School of Engineering, Northwestern University, Evanston, 60208, IL, United States
| | - Chengyong Wu
- Department of Respiratory and Critical Care Medicine, Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; Precision Medicine Key Laboratory of Sichuan Province & Precision Medicine Research Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jiaxing Wang
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Tennessee Health Science Center, Memphis, 38163, Tennessee, United States
| | - Chengdi Wang
- Department of Respiratory and Critical Care Medicine, Targeted Tracer Research and Development Laboratory, Institute of Respiratory Health, Frontiers Science Center for Disease-related Molecular Network, National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
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Alexa A, Sok P, Gross F, Albert K, Kobori E, Póti ÁL, Gógl G, Bento I, Kuang E, Taylor SS, Zhu F, Ciliberto A, Reményi A. A non-catalytic herpesviral protein reconfigures ERK-RSK signaling by targeting kinase docking systems in the host. Nat Commun 2022; 13:472. [PMID: 35078976 PMCID: PMC8789800 DOI: 10.1038/s41467-022-28109-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 01/07/2022] [Indexed: 12/16/2022] Open
Abstract
The Kaposi's sarcoma associated herpesvirus protein ORF45 binds the extracellular signal-regulated kinase (ERK) and the p90 Ribosomal S6 kinase (RSK). ORF45 was shown to be a kinase activator in cells but a kinase inhibitor in vitro, and its effects on the ERK-RSK complex are unknown. Here, we demonstrate that ORF45 binds ERK and RSK using optimized linear binding motifs. The crystal structure of the ORF45-ERK2 complex shows how kinase docking motifs recognize the activated form of ERK. The crystal structure of the ORF45-RSK2 complex reveals an AGC kinase docking system, for which we provide evidence that it is functional in the host. We find that ORF45 manipulates ERK-RSK signaling by favoring the formation of a complex, in which activated kinases are better protected from phosphatases and docking motif-independent RSK substrate phosphorylation is selectively up-regulated. As such, our data suggest that ORF45 interferes with the natural design of kinase docking systems in the host.
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Affiliation(s)
- Anita Alexa
- Biomolecular Interactions Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, H-1117, Budapest, Hungary
| | - Péter Sok
- Biomolecular Interactions Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, H-1117, Budapest, Hungary
| | - Fridolin Gross
- IFOM, Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | - Krisztián Albert
- Biomolecular Interactions Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, H-1117, Budapest, Hungary
| | - Evan Kobori
- Department of Chemistry and Biochemistry, University of California San Diego, San Diego, 9500 Gilman Drive, La Jolla, CA, 92093-0654, USA
| | - Ádám L Póti
- Biomolecular Interactions Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, H-1117, Budapest, Hungary
| | - Gergő Gógl
- Biomolecular Interactions Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, H-1117, Budapest, Hungary
| | - Isabel Bento
- European Molecular Biology Laboratory, Hamburg, Germany
| | - Ersheng Kuang
- Department of Biological Science, Florida State University, Tallahassee, FL, 32306-4370, USA
| | - Susan S Taylor
- Department of Pharmacology, University of California San Diego, 9500 Gilman Drive, La Jolla, San Diego, CA, 92093-0654, USA
| | - Fanxiu Zhu
- Department of Biological Science, Florida State University, Tallahassee, FL, 32306-4370, USA
| | - Andrea Ciliberto
- IFOM, Istituto FIRC di Oncologia Molecolare, 20139, Milan, Italy
| | - Attila Reményi
- Biomolecular Interactions Research Group, Institute of Organic Chemistry, Research Center for Natural Sciences, H-1117, Budapest, Hungary.
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RSK Isoforms in Acute Myeloid Leukemia. Biomedicines 2021; 9:biomedicines9070726. [PMID: 34202904 PMCID: PMC8301392 DOI: 10.3390/biomedicines9070726] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/20/2021] [Accepted: 06/22/2021] [Indexed: 12/21/2022] Open
Abstract
Ribosomal S6 Kinases (RSKs) are a group of serine/threonine kinases that function downstream of the Ras/Raf/MEK/ERK signaling pathway. Four RSK isoforms are directly activated by ERK1/2 in response to extracellular stimuli including growth factors, hormones, and chemokines. RSKs phosphorylate many cytosolic and nuclear targets resulting in the regulation of diverse cellular processes such as cell proliferation, survival, and motility. In hematological malignancies such as acute myeloid leukemia (AML), RSK isoforms are highly expressed and aberrantly activated resulting in poor outcomes and resistance to chemotherapy. Therefore, understanding RSK function in leukemia could lead to promising therapeutic strategies. This review summarizes the current information on human RSK isoforms and discusses their potential roles in the pathogenesis of AML and mechanism of pharmacological inhibitors.
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Rasmussen MK, Nielsen J, Kjellerup RB, Andersen SM, Rittig AH, Johansen C, Iversen L, Gesser B. Protein phosphatase 2Cδ/Wip1 regulates phospho-p90RSK2 activity in lesional psoriatic skin. J Inflamm Res 2017; 10:169-180. [PMID: 29290690 PMCID: PMC5735993 DOI: 10.2147/jir.s152869] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Objectives P90 ribosomal S6 kinase (RSK) 1 and 2 are serine/threonine protein kinases believed to mediate proliferation and apoptosis via the extracellular signal-regulated kinases (ERK1/2) signaling pathway. Macrophage migration inhibitory factor (MIF) and epidermal growth factor (EGF) are activators of this pathway and are elevated in the serum of patients with psoriasis compared with healthy controls. Studies on COS-7 cell cultures have shown that protein phosphatase 2Cδ (PP2Cδ) decreases the activity of RSK2 following EGF stimulation. We therefore hypothesize that PP2Cδ regulates RSK2 activity in psoriasis. Methods In paired biopsies from nonlesional (NL) and lesional (L) skins, we analyzed the level of RSK1, 2 phosphorylation and the expression of PP2Cδ isoforms, integrin-linked kinase-associated serine/threonine phosphatase (ILKAP) and wild-type p53-induced phosphatase 1 (Wip1) by Western blotting, immunofluorescence and coimmunoprecipitation with monoclonal antibody for RSK2. The induction of Wip1 by MIF or EGF was studied in cultured normal human keratinocytes. Results The protein level of RSK1, 2 phosphorylated at T573/T577 was significantly increased in L compared with NL psoriatic skin, while phosphorylation at S380/S386 was reduced in L compared with NL psoriatic skin when assayed by Western blotting and immunofluorescence microscopy. ILKAP expression was significantly higher in L than in NL skin, whereas Wip1 was expressed in similar amounts but showed increased coimmunoprecipitation with RSK2 in L compared with NL psoriatic skin. In cultured normal human keratinocytes stimulated with MIF, Wip1 phosphorylation and Wip1 expression were increased after 24 hours, but not when costimulated with dimethyl fumarate (DMF). The increased coimmunoprecipitation of Wip1 with RSK2 was significantly induced by EGF or MIF activation at 24 hours and could be significantly inhibited by DMF or the ERK1/2 inhibitor PD98059. Conclusion The complex formation of Wip1 with RSK2 indicates a direct interaction reducing P-RSK2 (S386) activation in L skin and indicates that Wip1 has a role in the pathogenesis of psoriasis.
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Affiliation(s)
- Mads K Rasmussen
- Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark
| | - Jakob Nielsen
- Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark
| | | | - Stine M Andersen
- Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark
| | - Anne H Rittig
- Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark
| | - Claus Johansen
- Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark
| | - Lars Iversen
- Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark
| | - Borbala Gesser
- Department of Dermatology, Aarhus University Hospital, Aarhus, Denmark
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Houles T, Roux PP. Defining the role of the RSK isoforms in cancer. Semin Cancer Biol 2017; 48:53-61. [PMID: 28476656 DOI: 10.1016/j.semcancer.2017.04.016] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 04/10/2017] [Accepted: 04/28/2017] [Indexed: 02/03/2023]
Abstract
The 90kDa ribosomal S6 kinase (RSK) family is a group of Ser/Thr protein kinases (RSK1-4) that function downstream of the Ras/mitogen-activated protein kinase (MAPK) signalling pathway. RSK regulates many substrates involved in cell survival, growth, and proliferation, and as such, deregulated RSK activity has been associated with multiple cancer types. RSK expression and activity are dysregulated in several malignancies, including breast, prostate, and lung cancer, and available evidence suggests that RSK may be a promising cancer therapeutic target. Current limitations include the lack of RSK inhibitors with suitable pharmacokinetics and selectivity toward particular isoforms. This review briefly describes the current knowledge on RSK activation and function, with a particular emphasis on RSK-dependent mechanisms associated with tumorigenesis and pharmacological inhibition.
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Affiliation(s)
- Thibault Houles
- Institute for Research in Immunology and Cancer (IRIC), Canada
| | - Philippe P Roux
- Institute for Research in Immunology and Cancer (IRIC), Canada; Department of Pathology and Cell Biology, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada.
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Casalvieri KA, Matheson CJ, Backos DS, Reigan P. Selective Targeting of RSK Isoforms in Cancer. Trends Cancer 2017; 3:302-312. [PMID: 28718440 DOI: 10.1016/j.trecan.2017.03.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 03/08/2017] [Accepted: 03/08/2017] [Indexed: 12/21/2022]
Abstract
The p90 ribosomal S6 kinase family (RSK1-4) is a group of highly conserved Ser/Thr kinases that act as downstream effectors of the Ras/Raf/MEK/ERK signaling pathway. The RSKs phosphorylate a range of substrates involved in transcription, translation, cell cycle regulation, and cell survival. Although the RSKs have a high degree of sequence homology, their functional differences in cancer are of great interest. Current RSK inhibitors target more than one RSK isoform, and this may limit their efficacy as anticancer agents. Here, we review the structure and function of the RSK kinases, their role in cancer growth and survival, and their potential as modulators of chemoresistance. In addition, we summarize the development of current RSK inhibitors and their limitations.
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Affiliation(s)
- Kimberly A Casalvieri
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, 12850 East Montview Boulevard, V20-2102, Aurora, CO 80045, USA
| | - Christopher J Matheson
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, 12850 East Montview Boulevard, V20-2102, Aurora, CO 80045, USA
| | - Donald S Backos
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, 12850 East Montview Boulevard, V20-2102, Aurora, CO 80045, USA
| | - Philip Reigan
- Department of Pharmaceutical Sciences, Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, 12850 East Montview Boulevard, V20-2102, Aurora, CO 80045, USA.
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The integrin-linked kinase-associated phosphatase (ILKAP) is a regulatory hub of ovarian cancer cell susceptibility to platinum drugs. Eur J Cancer 2016; 60:59-68. [DOI: 10.1016/j.ejca.2016.02.022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 12/04/2015] [Accepted: 02/25/2016] [Indexed: 01/13/2023]
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Bourgoin SG, Hui W. Role of mitogen- and stress-activated kinases in inflammatory arthritis. World J Pharmacol 2015; 4:265-273. [DOI: 10.5497/wjp.v4.i4.265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 09/10/2015] [Accepted: 10/19/2015] [Indexed: 02/06/2023] Open
Abstract
Lysophosphatidic acid (LPA) is a pleiotropic lipid mediator that promotes motility, survival, and the synthesis of chemokines/cytokines in human fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis. LPA activates several proteins within the mitogen activated protein (MAP) kinase signaling network, including extracellular signal-regulated kinases (ERK) 1/2 and p38 MAP kinase (MAPK). Upon docking to mitogen- and stress-activated kinases (MSKs), ERK1/2 and p38 MAPK phosphorylate serine and threonine residues within its C-terminal domain and cause autophosphorylation of MSKs. Activated MSKs can then directly phosphorylate cAMP response element-binding protein (CREB) at Ser133 in FLS. Phosphorylation of CREB by MSKs is essential for the production of pro-inflammatory and anti-inflammatory cytokines. However, other downstream effectors of MSK1/2 such as nuclear factor-kappa B, histone H3, and high mobility group nucleosome binding domain 1 may also regulate gene expression in immune cells involved in disease pathogenesis. MSKs are master regulators of cell function that integrate signals induced by growth factors, pro-inflammatory cytokines, and cellular stresses, as well as those induced by LPA.
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Martinez EC, Passariello CL, Li J, Matheson CJ, Dodge-Kafka K, Reigan P, Kapiloff MS. RSK3: A regulator of pathological cardiac remodeling. IUBMB Life 2015; 67:331-7. [PMID: 25988524 PMCID: PMC4449288 DOI: 10.1002/iub.1383] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 04/08/2015] [Indexed: 12/18/2022]
Abstract
The family of p90 ribosomal S6 kinases (RSKs) are pleiotropic effectors for extracellular signal-regulated kinase signaling pathways. Recently, RSK3 was shown to be important for pathological remodeling of the heart. Although cardiac myocyte hypertrophy can be compensatory for increased wall stress, in chronic heart diseases, this nonmitotic cell growth is usually associated with interstitial fibrosis, increased cell death, and decreased cardiac function. Although RSK3 is less abundant in the cardiac myocyte than other RSK family members, RSK3 appears to serve a unique role in cardiac myocyte stress responses. A potential mechanism conferring the unique function of RSK3 in the heart is anchoring by the scaffold protein muscle A-kinase anchoring protein β (mAKAPβ). Recent findings suggest that RSK3 should be considered as a therapeutic target for the prevention of heart failure, a clinical syndrome of major public health significance.
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Affiliation(s)
- Eliana C. Martinez
- Department of Pediatrics, Division of Cardiology, Cardiac Signal Transduction and Cellular Biology Laboratory, Interdisciplinary Stem Cell Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Catherine L. Passariello
- Department of Pediatrics, Division of Cardiology, Cardiac Signal Transduction and Cellular Biology Laboratory, Interdisciplinary Stem Cell Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Jinliang Li
- Department of Pediatrics, Division of Cardiology, Cardiac Signal Transduction and Cellular Biology Laboratory, Interdisciplinary Stem Cell Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Christopher J. Matheson
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO, USA
| | - Kimberly Dodge-Kafka
- Calhoun Center for Cardiology, University of Connecticut Health Center, Farmington, CT, USA
| | - Philip Reigan
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of Colorado, Aurora, CO, USA
| | - Michael S. Kapiloff
- Department of Pediatrics, Division of Cardiology, Cardiac Signal Transduction and Cellular Biology Laboratory, Interdisciplinary Stem Cell Institute, Miller School of Medicine, University of Miami, Miami, FL, USA
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Kheirallah S, Fruchon S, Ysebaert L, Blanc A, Capilla F, Marrot A, Alsaati T, Frenois FX, Benhadji KA, Fournié JJ, Laurent G, Bezombes C. The serine-threonine kinase p90RSK is a new target of enzastaurin in follicular lymphoma cells. Br J Pharmacol 2014; 170:1374-83. [PMID: 23992368 DOI: 10.1111/bph.12351] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 05/23/2013] [Accepted: 06/07/2013] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND AND PURPOSE Follicular lymphoma is the second most common non-Hodgkin's lymphoma and, despite the introduction of rituximab for its treatment, this disease is still considered incurable. Besides genetic alterations involving Bcl-2, Bcl-6 or c-Myc, follicular lymphoma cells often display altered B-cell receptor signalling pathways including overactive PKC and PI3K/Akt systems. EXPERIMENTAL APPROACH The effect of enzastaurin, an inhibitor of PKC, was evaluated both in vitro on follicular lymphoma cell lines and in vivo on a xenograft murine model. Using pharmacological inhibitors and siRNA transfection, we determined the different signalling pathways after enzastaurin treatment. KEY RESULTS Enzastaurin inhibited the serine-threonine kinase p90RSK which has downstream effects on GSK3β. Bad and p70S6K. These signalling proteins control follicular lymphoma cell survival and apoptosis; which accounted for the inhibition by enzastaurin of cell survival and its induction of apoptosis of follicular lymphoma cell lines in vitro. Importantly, these results were replicated in vivo where enzastaurin inhibited the growth of follicular lymphoma xenografts in mice. CONCLUSIONS AND IMPLICATIONS The targeting of p90RSK by enzastaurin represents a new therapeutic option for the treatment of follicular lymphoma.
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Affiliation(s)
- S Kheirallah
- INSERM UMR1037-Centre de Recherche en Cancérologie de Toulouse, Toulouse, France; Université Toulouse III Paul-Sabatier, Toulouse, France; ERL 5294 CNRS, BP3028, Hôpital Purpan, Toulouse, France; Institut Carnot Lymphome-CALYM, Toulouse, France; Laboratoire d'Excellence Toulouse Cancer-TOUCAN, Toulouse, France
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Wang Y, Liu Z, Cheng H, Gao T, Pan Z, Yang Q, Guo A, Xue Y. EKPD: a hierarchical database of eukaryotic protein kinases and protein phosphatases. Nucleic Acids Res 2013; 42:D496-502. [PMID: 24214991 PMCID: PMC3965077 DOI: 10.1093/nar/gkt1121] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We present here EKPD (http://ekpd.biocuckoo.org), a hierarchical database of eukaryotic protein kinases (PKs) and protein phosphatases (PPs), the key molecules responsible for the reversible phosphorylation of proteins that are involved in almost all aspects of biological processes. As extensive experimental and computational efforts have been carried out to identify PKs and PPs, an integrative resource with detailed classification and annotation information would be of great value for both experimentalists and computational biologists. In this work, we first collected 1855 PKs and 347 PPs from the scientific literature and various public databases. Based on previously established rationales, we classified all of the known PKs and PPs into a hierarchical structure with three levels, i.e. group, family and individual PK/PP. There are 10 groups with 149 families for the PKs and 10 groups with 33 families for the PPs. We constructed 139 and 27 Hidden Markov Model profiles for PK and PP families, respectively. Then we systematically characterized ∼50,000 PKs and >10,000 PPs in eukaryotes. In addition, >500 PKs and >400 PPs were computationally identified by ortholog search. Finally, the online service of the EKPD database was implemented in PHP + MySQL + JavaScript.
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Affiliation(s)
- Yongbo Wang
- Department of Biomedical Engineering, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
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Zhou W, Cao H, Yang X, Cong K, Wang W, Chen T, Yin H, Wu Z, Cai X, Liu T, Xiao J. Characterization of nuclear localization signal in the N terminus of integrin-linked kinase-associated phosphatase (ILKAP) and its essential role in the down-regulation of RSK2 protein signaling. J Biol Chem 2013; 288:6259-71. [PMID: 23329845 DOI: 10.1074/jbc.m112.432195] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Integrin-linked kinase-associated phosphatase (ILKAP) is a serine/threonine (S/T) phosphatase that belongs to the protein phosphatase 2C (PP2C) family. Many previous studies have demonstrated that ILKAP plays key roles in the regulation of cell survival and apoptosis. Researchers have thus far considered ILKAP a cytoplasmic protein that negatively regulates integrin signaling by interacting with and phosphorylating integrin-linked kinase 1 (ILK1). In this study, we found that both endogenous and tagged ILKAP mainly localize to the nucleus and that the nuclear transport of ILKAP is nuclear localization signal (NLS) importin-mediated. The ILKAP protein interacts directly with importin α1, α3, and α5. The NLS in ILKAP is located in the N-terminal region between amino acids 71 and 86, and the NLS-deleted ILKAP protein was distributed in the cytoplasm. In addition, we show that Lys-78 and Arg-79 are critical for the binding of ILKAP to importin α. We also found that nuclear ILKAP interacts with ribosomal protein S6 kinase-2 (RSK2) and induces apoptosis by inhibiting RSK2 activity and down-regulating the expression level of the RSK2 downstream substrate cyclin D1. These results indicate that ILKAP is a nuclear protein that regulates cell survival and apoptosis through the regulation of RSK2 signaling.
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Affiliation(s)
- Wang Zhou
- Changzheng Hospital, the Second Military Medical University, 415 Feng-yang Road, Shanghai 200433, China
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Abstract
The RSK (90 kDa ribosomal S6 kinase) family comprises a group of highly related serine/threonine kinases that regulate diverse cellular processes, including cell growth, proliferation, survival and motility. This family includes four vertebrate isoforms (RSK1, RSK2, RSK3 and RSK4), and single family member orthologues are also present in Drosophila and Caenorhabditis elegans. The RSK isoforms are downstream effectors of the Ras/ERK (extracellular-signal-regulated kinase) signalling pathway. Significant advances in the field of RSK signalling have occurred in the past few years, including several new functions ascribed to the RSK isoforms, the discovery of novel protein substrates and the implication of different RSK isoforms in cancer. Collectively, these new findings increase the diversity of biological functions regulated by RSK, and highlight potential new directions of research. In the present paper, we review the structure, expression and activation mechanisms of the RSK isoforms, and discuss their physiological roles on the basis of established substrates and recent discoveries.
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Højlys-Larsen KB, Sørensen KK, Jensen KJ, Gammeltoft S. Probing protein phosphatase substrate binding: affinity pull-down of ILKAP phosphatase 2C with phosphopeptides. MOLECULAR BIOSYSTEMS 2012; 8:1452-60. [DOI: 10.1039/c2mb05478g] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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16
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Activation and function of the MAPKs and their substrates, the MAPK-activated protein kinases. Microbiol Mol Biol Rev 2011; 75:50-83. [PMID: 21372320 DOI: 10.1128/mmbr.00031-10] [Citation(s) in RCA: 2090] [Impact Index Per Article: 160.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The mitogen-activated protein kinases (MAPKs) regulate diverse cellular programs by relaying extracellular signals to intracellular responses. In mammals, there are more than a dozen MAPK enzymes that coordinately regulate cell proliferation, differentiation, motility, and survival. The best known are the conventional MAPKs, which include the extracellular signal-regulated kinases 1 and 2 (ERK1/2), c-Jun amino-terminal kinases 1 to 3 (JNK1 to -3), p38 (α, β, γ, and δ), and ERK5 families. There are additional, atypical MAPK enzymes, including ERK3/4, ERK7/8, and Nemo-like kinase (NLK), which have distinct regulation and functions. Together, the MAPKs regulate a large number of substrates, including members of a family of protein Ser/Thr kinases termed MAPK-activated protein kinases (MAPKAPKs). The MAPKAPKs are related enzymes that respond to extracellular stimulation through direct MAPK-dependent activation loop phosphorylation and kinase activation. There are five MAPKAPK subfamilies: the p90 ribosomal S6 kinase (RSK), the mitogen- and stress-activated kinase (MSK), the MAPK-interacting kinase (MNK), the MAPK-activated protein kinase 2/3 (MK2/3), and MK5 (also known as p38-regulated/activated protein kinase [PRAK]). These enzymes have diverse biological functions, including regulation of nucleosome and gene expression, mRNA stability and translation, and cell proliferation and survival. Here we review the mechanisms of MAPKAPK activation by the different MAPKs and discuss their physiological roles based on established substrates and recent discoveries.
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17
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Sajid A, Arora G, Gupta M, Upadhyay S, Nandicoori VK, Singh Y. Phosphorylation of Mycobacterium tuberculosis Ser/Thr phosphatase by PknA and PknB. PLoS One 2011; 6:e17871. [PMID: 21423706 PMCID: PMC3052367 DOI: 10.1371/journal.pone.0017871] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2010] [Accepted: 02/11/2011] [Indexed: 11/30/2022] Open
Abstract
Background The integrated functions of 11 Ser/Thr protein kinases (STPKs) and one
phosphatase manipulate the phosphorylation levels of critical proteins in
Mycobacterium tuberculosis. In this study, we show that
the lone Ser/Thr phosphatase (PstP) is regulated through phosphorylation by
STPKs. Principal Findings PstP is phosphorylated by PknA and PknB and phosphorylation is influenced by
the presence of Zn2+-ions and inorganic phosphate (Pi). PstP
is differentially phosphorylated on the cytosolic domain with
Thr137, Thr141, Thr174 and
Thr290 being the target residues of PknB while
Thr137 and Thr174 are phosphorylated by PknA. The
Mn2+-ion binding residues Asp38 and
Asp229 are critical for the optimal activity of PstP and
substitution of these residues affects its phosphorylation status. Native
PstP and its phosphatase deficient mutant PstPcD38G
are phosphorylated by PknA and PknB in E. coli and addition
of Zn2+/Pi in the culture conditions affect the
phosphorylation level of PstP. Interestingly, the phosphorylated phosphatase
is more active than its unphosphorylated equivalent. Conclusions and Significance This study establishes the novel mechanisms for regulation of mycobacterial
Ser/Thr phosphatase. The results indicate that STPKs and PstP may regulate
the signaling through mutually dependent mechanisms. Consequently, PstP
phosphorylation may play a critical role in regulating its own activity.
Since, the equilibrium between phosphorylated and non-phosphorylated states
of mycobacterial proteins is still unexplained, understanding the regulation
of PstP may help in deciphering the signal transduction pathways mediated by
STPKs and the reversibility of the phenomena.
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Affiliation(s)
- Andaleeb Sajid
- Institute of Genomics and Integrative Biology
(CSIR), Delhi, India
| | - Gunjan Arora
- Institute of Genomics and Integrative Biology
(CSIR), Delhi, India
| | - Meetu Gupta
- Institute of Genomics and Integrative Biology
(CSIR), Delhi, India
| | - Sandeep Upadhyay
- National Institute of Immunology, Aruna Asaf
Ali Marg, New Delhi, India
| | | | - Yogendra Singh
- Institute of Genomics and Integrative Biology
(CSIR), Delhi, India
- * E-mail:
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18
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Cargnello M, Roux PP. Activation and Function of the MAPKs and Their Substrates, the MAPK-Activated Protein Kinases. Microbiol Mol Biol Rev 2011. [DOI: 78495111110.1128/mmbr.00031-10' target='_blank'>'"<>78495111110.1128/mmbr.00031-10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [78495111110.1128/mmbr.00031-10','', '10.1042/bj20040948')">Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
78495111110.1128/mmbr.00031-10" />
Abstract
SUMMARYThe mitogen-activated protein kinases (MAPKs) regulate diverse cellular programs by relaying extracellular signals to intracellular responses. In mammals, there are more than a dozen MAPK enzymes that coordinately regulate cell proliferation, differentiation, motility, and survival. The best known are the conventional MAPKs, which include the extracellular signal-regulated kinases 1 and 2 (ERK1/2), c-Jun amino-terminal kinases 1 to 3 (JNK1 to -3), p38 (α, β, γ, and δ), and ERK5 families. There are additional, atypical MAPK enzymes, including ERK3/4, ERK7/8, and Nemo-like kinase (NLK), which have distinct regulation and functions. Together, the MAPKs regulate a large number of substrates, including members of a family of protein Ser/Thr kinases termed MAPK-activated protein kinases (MAPKAPKs). The MAPKAPKs are related enzymes that respond to extracellular stimulation through direct MAPK-dependent activation loop phosphorylation and kinase activation. There are five MAPKAPK subfamilies: the p90 ribosomal S6 kinase (RSK), the mitogen- and stress-activated kinase (MSK), the MAPK-interacting kinase (MNK), the MAPK-activated protein kinase 2/3 (MK2/3), and MK5 (also known as p38-regulated/activated protein kinase [PRAK]). These enzymes have diverse biological functions, including regulation of nucleosome and gene expression, mRNA stability and translation, and cell proliferation and survival. Here we review the mechanisms of MAPKAPK activation by the different MAPKs and discuss their physiological roles based on established substrates and recent discoveries.
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Affiliation(s)
- Marie Cargnello
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada
- Molecular Biology Program, Université de Montréal, Montreal, Quebec, Canada
| | - Philippe P. Roux
- Institute for Research in Immunology and Cancer, Université de Montréal, Montreal, Quebec, Canada
- Molecular Biology Program, Université de Montréal, Montreal, Quebec, Canada
- Department of Pathology and Cell Biology, Faculty of Medicine, Université de Montréal, Montreal, Quebec, Canada
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19
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Hentschke M, Berneking L, Belmar Campos C, Buck F, Ruckdeschel K, Aepfelbacher M. Yersinia virulence factor YopM induces sustained RSK activation by interfering with dephosphorylation. PLoS One 2010; 5. [PMID: 20957203 PMCID: PMC2950144 DOI: 10.1371/journal.pone.0013165] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Accepted: 09/14/2010] [Indexed: 12/18/2022] Open
Abstract
Background Pathogenic yersiniae inject several effector proteins (Yops) into host cells, which subverts immune functions and enables the bacteria to survive within the host organism. YopM, whose deletion in enteropathogenic yersiniae results in a dramatic loss of virulence, has previously been shown to form a complex with and activate the multifunctional kinases PKN2 and RSK1 in transfected cells. Methodology/Principal Findings In a near physiological approach with double-affinity-tagged YopM being translocated into the macrophage cell line J774A.1 via the natural type three secretion system of Yersinia we verified the interaction of YopM with PKN2 and RSK1 and detected association with additional PKN and RSK isoforms. In transfected and infected cells YopM induced sustained phosphorylation of RSK at its activation sites serine-380 and serine-221 even in the absence of signalling from its upstream kinase ERK1/2, suggesting inhibition of dephosphorylation. ATP-depletion and in vitro assays using purified components directly confirmed that YopM shields RSK isoforms from phosphatase activity towards serines 380 and 221. Conclusions/Significance Our study suggests that during Yersinia infection YopM induces sustained activation of RSK by blocking dephosphorylation of its activatory phosphorylation sites. This may represent a novel mode of action of a bacterial virulence factor.
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Affiliation(s)
- Moritz Hentschke
- Institute of Medical Microbiology, Virology and Hygiene, University Medical Center Eppendorf, Hamburg, Germany.
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20
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Kostenko S, Shiryaev A, Dumitriu G, Gerits N, Moens U. Cross-talk between protein kinase A and the MAPK-activated protein kinases RSK1 and MK5. J Recept Signal Transduct Res 2010; 31:1-9. [PMID: 20849292 DOI: 10.3109/10799893.2010.515593] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Typical mammalian mitogen-activated protein kinase (MAPK) pathways consist of a cascade of three consecutive phosphorylation events exerted by a MAPK kinase kinase (MAPKKK), a MAPK kinase (MAPKK), and finally a MAPK. MAPKs not only target non-protein kinase substrates, they can also phosphorylate other protein kinases designated as MAPK-activated protein kinases (MAPKAPK). The MAPKAPK family includes the ribosomal-S6-kinases (RSK1-4), the MAPK-interacting kinases (MNK1 and 2), the mitogen-and stress-activated kinases (MSK1 and 2), and the MAPKAPK (MK2, 3, and 5) subfamilies. Although several reports indicate extensive cross-talk between the MAPK and protein kinase A (PKA) pathways, evidence of a direct interaction at the level of the MAPKAPK only appeared recently. The MAPKAPKs RSK1 and MK5 can bind to PKA, but the features of these interactions are distinct. This review discusses the different characteristics of regulating the activity and subcellular localization of MK5 and RSK1 by PKA and the functional implications of these interactions.
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Affiliation(s)
- Sergiy Kostenko
- Faculty of Health Sciences, Institute of Medical Biology, University of Tromsø, Tromsø, Norway
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21
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Chaturvedi D, Cohen MS, Taunton J, Patel TB. The PKARIalpha subunit of protein kinase A modulates the activation of p90RSK1 and its function. J Biol Chem 2009; 284:23670-81. [PMID: 19570980 DOI: 10.1074/jbc.m109.032813] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Previously, we showed that interactions between p90(RSK1) (RSK1) and the subunits of type I protein kinase A (PKA) regulate the activity of PKA and cellular distribution of active RSK1 (Chaturvedi, D., Poppleton, H. M., Stringfield, T., Barbier, A., and Patel, T. B. (2006) Mol. Cell Biol. 26, 4586-4600). Here we examined the role of the PKARIalpha subunit of PKA in regulating RSK1 activation and cell survival. In mouse lung fibroblasts, silencing of the PKARIalpha increased the phosphorylation and activation of RSK1, but not of RSK2 and RSK3, in the absence of any stimulation. Silencing of PKARIalpha also decreased the nuclear accumulation of active RSK1 and increased its cytoplasmic content. The increased activation of RSK1 in the absence of any agonist and changes in its subcellular redistribution resulted in increased phosphorylation of its cytoplasmic substrate BAD and increased cell survival. The activity of PKA and phosphorylation of BAD (Ser-155) were also enhanced when PKARIalpha was silenced, and this, in part, contributed to increased cell survival in unstimulated cells. Furthermore, we show that RSK1, PKA subunits, D-AKAP1, and protein phosphatase 2A catalytic subunit (PP2Ac) exist in a complex, and dissociation of RSK1 from D-AKAP1 by either silencing of PKARIalpha, depletion of D-AKAP1, or by using a peptide that competes with PKARIalpha for binding to AKAPs, decreased the amount of PP2Ac in the RSK1 complex. We also demonstrate that PP2Ac is one of the phosphatases that dephosphorylates RSK, but not ERK1/2. Thus, in unstimulated cells, the increased phosphorylation and activation of RSK1 after silencing of PKARIalpha or depletion of D-AKAP1 are due to decreased association of PP2Ac in the RSK1 complex.
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Affiliation(s)
- Deepti Chaturvedi
- Department of Pharmacology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois 60153, USA
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22
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Anjum R, Blenis J. The RSK family of kinases: emerging roles in cellular signalling. Nat Rev Mol Cell Biol 2008; 9:747-58. [PMID: 18813292 DOI: 10.1038/nrm2509] [Citation(s) in RCA: 570] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The 90 kDa ribosomal S6 kinase (RSK) family of proteins is a group of highly conserved Ser/Thr kinases that regulate diverse cellular processes, such as cell growth, cell motility, cell survival and cell proliferation. RSKs are downstream effectors of the Ras-extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) signalling cascade. Significant advances in the field of RSK and ERK/MAPK signalling have occurred in the past few years, including biological insights and the discovery of novel substrates and new RSK regulatory mechanisms. Collectively, these data expand the current models of RSK signalling and highlight potential directions of research in RSK-mediated survival, growth, proliferation and migration.
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Affiliation(s)
- Rana Anjum
- Department of Cell Biology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA
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23
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Lammers T, Lavi S. Role of type 2C protein phosphatases in growth regulation and in cellular stress signaling. Crit Rev Biochem Mol Biol 2008; 42:437-61. [PMID: 18066953 DOI: 10.1080/10409230701693342] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A number of interesting features, phenotypes, and potential clinical applications have recently been ascribed to the type 2C family of protein phosphatases. Thus far, 16 different PP2C genes have been identified in the human genome, encoding (by means of alternative splicing) for at least 22 different isozymes. Virtually ever since their discovery, type 2C phosphatases have been predominantly linked to cell growth and to cellular stress signaling. Here, we provide an overview of the involvement of type 2C phosphatases in these two processes, and we show that four of them (PP2Calpha, PP2Cbeta, ILKAP, and PHLPP) can be expected to function as tumor suppressor proteins, and one as an oncoprotein (PP2Cdelta /Wip1). In addition, we demonstrate that in virtually all cases in which they have been linked to the stress response, PP2Cs act as inhibitors of cellular stress signaling. Based on the vast amount of experimental evidence obtained thus far, it therefore seems justified to conclude that type 2C protein phosphatases are important physiological regulators of cell growth and of cellular stress signaling.
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Affiliation(s)
- Twan Lammers
- Department of Innovative Cancer Diagnosis and Therapy, German Cancer Research Center, Heidelberg, Germany.
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24
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Klumpp S, Thissen MC, Krieglstein J. Protein phosphatases types 2Cα and 2Cβ in apoptosis. Biochem Soc Trans 2006; 34:1370-5. [PMID: 17073821 DOI: 10.1042/bst0341370] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This mini-review highlights the involvement of PP2C (protein phosphatase type 2C) family members α and β in apoptosis. The activity of these isoenzymes can be stimulated by unsaturated fatty acids with special structural features, e.g. oleic acid. Those fatty acids capable of activating PP2Cα and PP2Cβ in vitro induce apoptosis in various cell types as shown here for neurons and endothelial cells. Using RNA interference to reduce the amount of PP2Cα and PP2Cβ results in cells significantly less susceptible to the apoptotic effect of oleic acid. Increased endothelial cell death is considered to be an initial step of atherogenesis. Thus activation of PP2C by physiological unbound (‘free’) unsaturated fatty acids (liberated from lipoproteins) could represent a crucial mechanism in the development of atherosclerosis.
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Affiliation(s)
- S Klumpp
- Institut für Pharmazeutische und Medizinische Chemie, Westfälische Wilhelms-Universität, Münster, Germany.
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25
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Vanden Berghe W, Dijsselbloem N, Vermeulen L, Ndlovu 'MN, Boone E, Haegeman G. Attenuation of mitogen- and stress-activated protein kinase-1-driven nuclear factor-kappaB gene expression by soy isoflavones does not require estrogenic activity. Cancer Res 2006; 66:4852-62. [PMID: 16651441 DOI: 10.1158/0008-5472.can-05-2957] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We have analyzed in molecular detail how soy isoflavones (genistein, daidzein, and biochanin A) suppress nuclear factor-kappaB (NF-kappaB)-driven interleukin-6 (IL6) expression. In addition to its physiologic immune function as an acute stress cytokine, sustained elevated expression levels of IL6 promote chronic inflammatory disorders, aging frailty, and tumorigenesis. Our results in estrogen-unresponsive fibroblasts, mitogen- and stress-activated protein kinase (MSK) knockout cells, and estrogen receptor (ER)-deficient breast tumor cells show that phytoestrogenic isoflavones can selectively block nuclear NF-kappaB transactivation of specific target genes (in particular IL6), independently of their estrogenic activity. This occurs via attenuation of mitogen-activated protein/extracellular signal-regulated kinase (ERK) kinase (MEK) and ERK activity, which further down-regulates MSK-dependent NF-kappaB p65 and histone H3 phosphorylation. As constitutive NF-kappaB and MSK activity are hallmarks of aggressive metastatic ER-deficient breast cancer, the MSK signaling pathway may become an attractive target for chemotherapy.
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Affiliation(s)
- Wim Vanden Berghe
- Laboratory for Eukaryotic Gene Expression and Signal Transduction, Department of Molecular Biology, Ghent University, Gent, Belgium.
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26
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Nelson KK, Subbaram S, Connor KM, Dasgupta J, Ha XF, Meng TC, Tonks NK, Melendez JA. Redox-dependent matrix metalloproteinase-1 expression is regulated by JNK through Ets and AP-1 promoter motifs. J Biol Chem 2006; 281:14100-10. [PMID: 16569638 DOI: 10.1074/jbc.m601820200] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Reactive oxygen species have been shown to play an important role in the regulation of distinct signaling cascades, many of which act upon the production of matrix metalloproteinases (MMP). Using a series of redox-engineered cell lines we have previously demonstrated that MMP-1 expression is sensitive to the alterations in the steady state production of H2O2 (Ranganathan, A. C., Nelson, K. K., Rodriguez, A. M., Kim, K. H., Tower, G. B., Rutter, J. L., Brinckerhoff, C. E., Epstein, C. J., Huang, T. T., Jeffrey, J. J., and Melendez, J. A. (2001) J. Biol. Chem. 276, 14264-14270). In the present study, we investigate the molecular mechanisms involved in the H2O2-mediated induction of MMP-1. Mutational analysis of an MMP-1 promoter indicates that both the single nucleotide polymorphism creating an Ets binding site at -1607 and a proximal AP-1 site at -1602 are required for maximal H2O2-dependent transcription. The redox-sensitive MMP-1 protein expression requires activation of both ERK1/2 and JNK pathways. Importantly, JNK signaling is largely responsible for the H2O2 sensitivity of the MMP-1 promoter, whereas ERK1/2 contributes to both its basal and H2O2 dependence. H2O2 control of Ets-1 expression was ERK1/2-dependent whereas that of c-Jun requires both ERK1/2 and JNK signaling. Chromatin immunoprecipitation assays indicate that binding of the histone acetyltransferase, p300, and the transcription factors Ets-1 and c-Jun to the MMP-1 promoter is redox sensitive. The redox sensitivity of MMP-1 expression is also associated with an increase in the abundance of oxidatively inactivated protein-tyrosine phosphatases. Targeted cytosolic or mitochondrial scavenging of H2O2 prevented all of the aforementioned signals. These studies provide substantial insight into the mechanisms underlying the redox-dependent control of MMP-1 and may lead to the development of novel targeted antioxidant-based inhibitory therapies for controlling MMP-1 expression during degenerative disease processes.
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Affiliation(s)
- Kristin K Nelson
- Center for Immunology and Microbial Disease, Albany Medical College, Albany, New York 12208, USA
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