1
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Salamh S, Sayyed-Ahmad A. Investigating the effects of cysteine-118 oxidation on G12D KRas structure and dynamics: insights from MD simulations. J Biomol Struct Dyn 2024; 42:6968-6981. [PMID: 37480262 DOI: 10.1080/07391102.2023.2238080] [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: 06/24/2023] [Accepted: 07/11/2023] [Indexed: 07/23/2023]
Abstract
Mutations of Ras proteins are believed to be among the most prominent causes of cancer. There is increasing evidence that the activity of Ras may be controlled by the redox state of cysteine residues located within the NKCD motif. This redox signaling is critical to both physiological and pathological processes and occurs when C118 is oxidized in a reversible manner. In this study, we used atomistic molecular dynamics simulations and Markov state models to investigate the structural and conformational effects of C118 oxidation on the oncogenic mutant KRas(G12D). While both mutants share common features and exhibit some distinct conformational states and fluctuations, we have found that the oxidized variant KRas(G12D/C118SOH) is more dynamic than the unoxidized counterpart, particularly in the switch II region. Additionally, C118 oxidation is found to alter the structure of the nucleotide-binding site and the switch regions as well as perturb the conformational equilibrium between Ras active and inactive states. These conformational preferences may alter the affinity to different effectors, resulting in selective downstream activation. Our results are anticipated to help future drug development efforts aimed at KRAS-related anticancer treatment.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Shimaa Salamh
- Department of Physics, Birzeit University, Birzeit, Palestine
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2
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Takahashi M, Sakamoto A, Morikawa H. Atmospheric nitrogen dioxide suppresses the activity of phytochrome interacting factor 4 to suppress hypocotyl elongation. PLANTA 2024; 260:42. [PMID: 38958765 PMCID: PMC11222245 DOI: 10.1007/s00425-024-04468-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 06/11/2024] [Indexed: 07/04/2024]
Abstract
MAIN CONCLUSION Ambient concentrations of atmospheric nitrogen dioxide (NO2) inhibit the binding of PIF4 to promoter regions of auxin pathway genes to suppress hypocotyl elongation in Arabidopsis. Ambient concentrations (10-50 ppb) of atmospheric nitrogen dioxide (NO2) positively regulate plant growth to the extent that organ size and shoot biomass can nearly double in various species, including Arabidopsis thaliana (Arabidopsis). However, the precise molecular mechanism underlying NO2-mediated processes in plants, and the involvement of specific molecules in these processes, remain unknown. We measured hypocotyl elongation and the transcript levels of PIF4, encoding a bHLH transcription factor, and its target genes in wild-type (WT) and various pif mutants grown in the presence or absence of 50 ppb NO2. Chromatin immunoprecipitation assays were performed to quantify binding of PIF4 to the promoter regions of its target genes. NO2 suppressed hypocotyl elongation in WT plants, but not in the pifq or pif4 mutants. NO2 suppressed the expression of target genes of PIF4, but did not affect the transcript level of the PIF4 gene itself or the level of PIF4 protein. NO2 inhibited the binding of PIF4 to the promoter regions of two of its target genes, SAUR46 and SAUR67. In conclusion, NO2 inhibits the binding of PIF4 to the promoter regions of genes involved in the auxin pathway to suppress hypocotyl elongation in Arabidopsis. Consequently, PIF4 emerges as a pivotal participant in this regulatory process. This study has further clarified the intricate regulatory mechanisms governing plant responses to environmental pollutants, thereby advancing our understanding of how plants adapt to changing atmospheric conditions.
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Affiliation(s)
- Misa Takahashi
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi, Hiroshima, 739-8526, Japan.
| | - Atsushi Sakamoto
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi, Hiroshima, 739-8526, Japan
| | - Hiromichi Morikawa
- School of Science, Hiroshima University, Higashi, Hiroshima, 739-8526, Japan
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3
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Simão S, Agostinho RR, Martínez-Ruiz A, Araújo IM. Regulation of Ras Signaling by S-Nitrosylation. Antioxidants (Basel) 2023; 12:1562. [PMID: 37627556 PMCID: PMC10451275 DOI: 10.3390/antiox12081562] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 07/28/2023] [Accepted: 08/02/2023] [Indexed: 08/27/2023] Open
Abstract
Ras are a family of small GTPases that function as signal transduction mediators and are involved in cell proliferation, migration, differentiation and survival. The significance of Ras is further evidenced by the fact that Ras genes are among the most mutated oncogenes in different types of cancers. After translation, Ras proteins can be targets of post-translational modifications (PTM), which can alter the intracellular dynamics of the protein. In this review, we will focus on how S-nitrosylation of Ras affects the way these proteins interact with membranes, its cellular localization, and its activity. S-Nitrosylation occurs when a nitrosyl moiety of nitric oxide (NO) is covalently attached to a thiol group of a cysteine residue in a target protein. In Ras, the conserved Cys118 is the most surface-exposed Cys and the preferable residue for NO action, leading to the initiation of transduction events. Ras transduces the mitogen-activated protein kinases (MAPK), the phosphoinositide-3 kinase (PI3K) and the RalGEF cellular pathways. S-Nitrosylation of elements of the RalGEF cascade remains to be identified. On the contrary, it is well established that several components of the MAPK and PI3K pathways, as well as different proteins associated with these cascades, can be modified by S-nitrosylation. Overall, this review presents a better understanding of Ras S-nitrosylation, increasing the knowledge on the dynamics of these proteins in the presence of NO and the underlying implications in cellular signaling.
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Affiliation(s)
- Sónia Simão
- Algarve Biomedical Center Research Institute (ABC-RI), University of Algarve, 8005-139 Faro, Portugal;
- Faculty of Medicine and Biomedical Sciences, University of Algarve, 8005-139 Faro, Portugal
| | - Rafaela Ribeiro Agostinho
- Algarve Biomedical Center Research Institute (ABC-RI), University of Algarve, 8005-139 Faro, Portugal;
- Faculty of Medicine and Biomedical Sciences, University of Algarve, 8005-139 Faro, Portugal
| | - Antonio Martínez-Ruiz
- Unidad de Investigación, Hospital Universitario Santa Cristina, Instituto de Investigación Sanitaria Princesa, 28009 Madrid, Spain;
- Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - Inês Maria Araújo
- Algarve Biomedical Center Research Institute (ABC-RI), University of Algarve, 8005-139 Faro, Portugal;
- Faculty of Medicine and Biomedical Sciences, University of Algarve, 8005-139 Faro, Portugal
- Champalimaud Research Program, 1400-038 Lisbon, Portugal
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4
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Liu S, Xu S, Liu S, Chen H. Importance of DJ-1 in autophagy regulation and disease. Arch Biochem Biophys 2023:109672. [PMID: 37336341 DOI: 10.1016/j.abb.2023.109672] [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: 04/17/2023] [Revised: 05/28/2023] [Accepted: 06/16/2023] [Indexed: 06/21/2023]
Abstract
Autophagy is a highly conserved biological process that has evolved across evolution. It can be activated by various external stimuli including oxidative stress, amino acid starvation, infection, and hypoxia. Autophagy is the primary mechanism for preserving cellular homeostasis and is implicated in the regulation of metabolism, cell differentiation, tolerance to starvation conditions, and resistance to aging. As a multifunctional protein, DJ-1 is commonly expressed in vivo and is associated with a variety of biological processes. Its most widely studied role is its function as an oxidative stress sensor that inhibits the production of excessive reactive oxygen species (ROS) in the mitochondria and subsequently the cellular damage caused by oxidative stress. In recent years, many studies have identified DJ-1 as another important factor regulating autophagy; it regulates autophagy in various ways, most commonly by regulating the oxidative stress response. In particular, DJ-1-regulated autophagy is involved in cancer progression and plays a key role in alleviating neurodegenerative diseases(NDS) and defective reperfusion diseases. It could serve as a potential target for the regulation of autophagy and participate in disease treatment as a meaningful modality. Therefore, exploring DJ-1-regulated autophagy could provide new avenues for future disease treatment.
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Affiliation(s)
- Shiyi Liu
- The Key Laboratory of Basic Pharmacology, School of Pharmaceutical Science, Nanchang University, Nanchang, 330006, PR China; Second Clinical Medical College, Nanchang University, Nanchang, 330006, PR China
| | - Sheng Xu
- Second Clinical Medical College, Nanchang University, Nanchang, 330006, PR China
| | - Song Liu
- The Key Laboratory of Basic Pharmacology, School of Pharmaceutical Science, Nanchang University, Nanchang, 330006, PR China
| | - Heping Chen
- The Key Laboratory of Basic Pharmacology, School of Pharmaceutical Science, Nanchang University, Nanchang, 330006, PR China.
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5
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Zuchegna C, Porcellini A, Messina S. Redox-sensitive small GTPase H-Ras in murine astrocytes, an in vitro study. Redox Rep 2022; 27:150-157. [PMID: 35822835 PMCID: PMC9291712 DOI: 10.1080/13510002.2022.2094109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Background Although the protooncogenes small GTPases Ras are redox-sensitive proteins, how they are regulated by redox signaling in the central nervous system (CNS) is still poorly understood. Alteration in redox-sensitive targets by redox signaling may have myriad effects on Ras stability, activity and localization. Redox-mediated changes in astrocytic RAS may contribute to the control of redox homeostasis in the CNS that is connected to the pathogenesis of many diseases. Results and Methods Here, we investigated the transient physiological induction, at both transcriptional and translational levels, of small GTPases Ras in response to redox stimulation. Cultured astrocytes were treated with hydrogen peroxide as in bolus addition and relative mRNA levels of murine hras and kras genes were detected by qRT-PCR. We found that de novo transcription of hras mRNA in reactive astrocytes is redox-sensitive and mimics the prototypical redox-sensitive gene iNOS. Protein abundance in combination with protein turnover measurements by cycloheximide-chase experiments revealed distinct translation efficiency, GTP-bound enrichment, and protein turnover rates between the two isoforms H-Ras and K-Ras. Conclusion Reports from recent years support a significant role of H-Ras in driving redox processes. Beyond its canonical functions, Ras may impact on the core astrocytic cellular machinery that operates during redox stimulation.
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Affiliation(s)
- Candida Zuchegna
- Dipartimento di Biologia, Complesso Universitario di Monte Sant'Angelo, Università degli Studi di Napoli "Federico II", Napoli, Italia
| | - Antonio Porcellini
- Dipartimento di Biologia, Complesso Universitario di Monte Sant'Angelo, Università degli Studi di Napoli "Federico II", Napoli, Italia
| | - Samantha Messina
- Dipartimento di Scienze, Università degli Studi Roma Tre, Roma, Italia
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6
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Huynh MV, Parsonage D, Forshaw TE, Chirasani VR, Hobbs GA, Wu H, Lee J, Furdui CM, Poole LB, Campbell SL. Oncogenic KRAS G12C: Kinetic and redox characterization of covalent inhibition. J Biol Chem 2022; 298:102186. [PMID: 35753348 PMCID: PMC9352912 DOI: 10.1016/j.jbc.2022.102186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2022] [Revised: 06/14/2022] [Accepted: 06/16/2022] [Indexed: 12/02/2022] Open
Abstract
The recent development of mutant-selective inhibitors for the oncogenic KRASG12C allele has generated considerable excitement. These inhibitors covalently engage the mutant C12 thiol located within the phosphoryl binding loop of RAS, locking the KRASG12C protein in an inactive state. While clinical trials of these inhibitors have been promising, mechanistic questions regarding the reactivity of this thiol remain. Here, we show by NMR and an independent biochemical assay that the pKa of the C12 thiol is depressed (pKa ∼7.6), consistent with susceptibility to chemical ligation. Using a validated fluorescent KRASY137W variant amenable to stopped-flow spectroscopy, we characterized the kinetics of KRASG12C fluorescence changes upon addition of ARS-853 or AMG 510, noting that at low temperatures, ARS-853 addition elicited both a rapid first phase of fluorescence change (attributed to binding, Kd = 36.0 ± 0.7 μM) and a second, slower pH-dependent phase, taken to represent covalent ligation. Consistent with the lower pKa of the C12 thiol, we found that reversible and irreversible oxidation of KRASG12C occurred readily both in vitro and in the cellular environment, preventing the covalent binding of ARS-853. Moreover, we found that oxidation of the KRASG12C Cys12 to a sulfinate altered RAS conformation and dynamics to be more similar to KRASG12D in comparison to the unmodified protein, as assessed by molecular dynamics simulations. Taken together, these findings provide insight for future KRASG12C drug discovery efforts, and identify the occurrence of G12C oxidation with currently unknown biological ramifications.
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Affiliation(s)
- Minh V Huynh
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Derek Parsonage
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Tom E Forshaw
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Venkat R Chirasani
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - G Aaron Hobbs
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Hanzhi Wu
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Jingyun Lee
- Wake Forest Baptist Comprehensive Cancer Center, Winston-Salem, North Carolina, USA
| | - Cristina M Furdui
- Department of Internal Medicine, Section on Molecular Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA; Wake Forest Baptist Comprehensive Cancer Center, Winston-Salem, North Carolina, USA; Center for Redox Biology and Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
| | - Leslie B Poole
- Department of Biochemistry, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA; Wake Forest Baptist Comprehensive Cancer Center, Winston-Salem, North Carolina, USA; Center for Redox Biology and Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA.
| | - Sharon L Campbell
- Department of Biochemistry & Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA; Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA.
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7
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Campbell SL, Philips MR. Post-translational modification of RAS proteins. Curr Opin Struct Biol 2021; 71:180-192. [PMID: 34365229 DOI: 10.1016/j.sbi.2021.06.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 06/25/2021] [Indexed: 11/26/2022]
Abstract
Mutations of RAS genes drive cancer more frequently than any other oncogene. RAS proteins integrate signals from a wide array of receptors and initiate downstream signaling through pathways that control cellular growth. RAS proteins are fundamentally binary molecular switches in which the off/on state is determined by the binding of GDP or GTP, respectively. As such, the intrinsic and regulated nucleotide-binding and hydrolytic properties of the RAS GTPase were historically believed to account for the entirety of the regulation of RAS signaling. However, it is increasingly clear that RAS proteins are also regulated by a vast array of post-translational modifications (PTMs). The current challenge is to understand what are the functional consequences of these modifications and which are physiologically relevant. Because PTMs are catalyzed by enzymes that may offer targets for drug discovery, the study of RAS PTMs has been a high priority for RAS biologists.
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Affiliation(s)
| | - Mark R Philips
- Perlmutter Cancer Center, NYU Grossman School of Medicine, USA
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8
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Osaka N, Hirota Y, Ito D, Ikeda Y, Kamata R, Fujii Y, Chirasani VR, Campbell SL, Takeuchi K, Senda T, Sasaki AT. Divergent Mechanisms Activating RAS and Small GTPases Through Post-translational Modification. Front Mol Biosci 2021; 8:707439. [PMID: 34307463 PMCID: PMC8295990 DOI: 10.3389/fmolb.2021.707439] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 06/22/2021] [Indexed: 12/12/2022] Open
Abstract
RAS is a founding member of the RAS superfamily of GTPases. These small 21 kDa proteins function as molecular switches to initialize signaling cascades involved in various cellular processes, including gene expression, cell growth, and differentiation. RAS is activated by GTP loading and deactivated upon GTP hydrolysis to GDP. Guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs) accelerate GTP loading and hydrolysis, respectively. These accessory proteins play a fundamental role in regulating activities of RAS superfamily small GTPase via a conserved guanine binding (G)-domain, which consists of five G motifs. The Switch regions lie within or proximal to the G2 and G3 motifs, and undergo dynamic conformational changes between the GDP-bound "OFF" state and GTP-bound "ON" state. They play an important role in the recognition of regulatory factors (GEFs and GAPs) and effectors. The G4 and G5 motifs are the focus of the present work and lie outside Switch regions. These motifs are responsible for the recognition of the guanine moiety in GTP and GDP, and contain residues that undergo post-translational modifications that underlie new mechanisms of RAS regulation. Post-translational modification within the G4 and G5 motifs activates RAS by populating the GTP-bound "ON" state, either through enhancement of intrinsic guanine nucleotide exchange or impairing GAP-mediated down-regulation. Here, we provide a comprehensive review of post-translational modifications in the RAS G4 and G5 motifs, and describe the role of these modifications in RAS activation as well as potential applications for cancer therapy.
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Affiliation(s)
- Natsuki Osaka
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Japan
| | - Yoshihisa Hirota
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
- Department of Bioscience and Engineering, College of Systems Engineering and Science, Shibaura Institute of Technology, Saitama, Japan
| | - Doshun Ito
- Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Japan
- Faculty of Environment and Information Studies, Keio University, Fujisawa, Japan
| | - Yoshiki Ikeda
- Department of Molecular Genetics, Institute of Biomedical Science, Kansai Medical University, Osaka, Japan
| | - Ryo Kamata
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Japan
| | - Yuki Fujii
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
- Graduate School of Science, Osaka City University, Osaka, Japan
| | - Venkat R. Chirasani
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Sharon L. Campbell
- Department of Biochemistry and Biophysics and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Koh Takeuchi
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Science and Technology, Tokyo, Japan
| | - Toshiya Senda
- Structural Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Japan
- Department of Accelerator Science, School of High Energy Accelerator Science, SOKENDAI (The Graduate University for Advanced Studies), Tsukuba, Japan
- Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Japan
| | - Atsuo T. Sasaki
- Institute for Advanced Biosciences, Keio University, Tsuruoka, Japan
- Division of Hematology and Oncology, Department of Internal Medicine, University of Cincinnati College of Medicine, Cincinnati, OH, United States
- Department of Cancer Biology, University of Cincinnati College of Medicine, Columbus, OH, United States
- Department of Neurosurgery, Brain Tumor Center at UC Gardner Neuroscience Institute, Cincinnati, OH, United States
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9
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Kramer-Drauberg M, Ambrogio C. Discoveries in the redox regulation of KRAS. Int J Biochem Cell Biol 2020; 131:105901. [PMID: 33309959 DOI: 10.1016/j.biocel.2020.105901] [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: 10/05/2020] [Revised: 11/27/2020] [Accepted: 12/05/2020] [Indexed: 10/22/2022]
Abstract
Oncogenic KRAS is one of the most common drivers of human cancer. Despite intense research, no effective therapy to directly inhibit oncogenic KRAS has yet been approved and KRAS mutant tumors remain associated with a poor prognosis. This short review discusses the current knowledge of the redox regulation of RAS and examines the newest findings on cysteine 118 (C118) as a potential novel target for KRAS inhibition.
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Affiliation(s)
- Maximilian Kramer-Drauberg
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Torino, Italy
| | - Chiara Ambrogio
- Department of Molecular Biotechnology and Health Sciences, Molecular Biotechnology Center, University of Torino, Torino, Italy; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02215, USA.
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10
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Abstract
RAS was identified as a human oncogene in the early 1980s and subsequently found to be mutated in nearly 30% of all human cancers. More importantly, RAS plays a central role in driving tumor development and maintenance. Despite decades of effort, there remain no FDA approved drugs that directly inhibit RAS. The prevalence of RAS mutations in cancer and the lack of effective anti-RAS therapies stem from RAS' core role in growth factor signaling, unique structural features, and biochemistry. However, recent advances have brought promising new drugs to clinical trials and shone a ray of hope in the field. Here, we will exposit the details of RAS biology that illustrate its key role in cell signaling and shed light on the difficulties in therapeutically targeting RAS. Furthermore, past and current efforts to develop RAS inhibitors will be discussed in depth.
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Affiliation(s)
- J Matthew Rhett
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States
| | - Imran Khan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States
| | - John P O'Bryan
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, United States; Ralph H. Johnson VA Medical Center, Charleston, SC, United States.
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11
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Kramer-Drauberg M, Liu JL, Desjardins D, Wang Y, Branicky R, Hekimi S. ROS regulation of RAS and vulva development in Caenorhabditis elegans. PLoS Genet 2020; 16:e1008838. [PMID: 32544191 PMCID: PMC7319342 DOI: 10.1371/journal.pgen.1008838] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 06/26/2020] [Accepted: 05/07/2020] [Indexed: 12/28/2022] Open
Abstract
Reactive oxygen species (ROS) are signalling molecules whose study in intact organisms has been hampered by their potential toxicity. This has prevented a full understanding of their role in organismal processes such as development, aging and disease. In Caenorhabditis elegans, the development of the vulva is regulated by a signalling cascade that includes LET-60ras (homologue of mammalian Ras), MPK-1 (ERK1/2) and LIN-1 (an ETS transcription factor). We show that both mitochondrial and cytoplasmic ROS act on a gain-of-function (gf) mutant of the LET-60ras protein through a redox-sensitive cysteine (C118) previously identified in mammals. We show that the prooxidant paraquat as well as isp-1, nuo-6 and sod-2 mutants, which increase mitochondrial ROS, inhibit the activity of LET-60rasgf on vulval development. In contrast, the antioxidant NAC and loss of sod-1, both of which decrease cytoplasmic H202, enhance the activity of LET-60rasgf. CRISPR replacement of C118 with a non-oxidizable serine (C118S) stimulates LET-60rasgf activity, whereas replacement of C118 with aspartate (C118D), which mimics a strongly oxidised cysteine, inhibits LET-60rasgf. These data strongly suggest that C118 is oxidized by cytoplasmic H202 generated from dismutation of mitochondrial and/or cytoplasmic superoxide, and that this oxidation inhibits LET-60ras. This contrasts with results in cultured mammalian cells where it is mostly nitric oxide, which is not found in worms, that oxidizes C118 and activates Ras. Interestingly, PQ, NAC and the C118S mutation do not act on the phosphorylation of MPK-1, suggesting that oxidation of LET-60ras acts on an as yet uncharacterized MPK-1-independent pathway. We also show that elevated cytoplasmic superoxide promotes vulva formation independently of C118 of LET-60ras and downstream of LIN-1. Finally, we uncover a role for the NADPH oxidases (BLI-3 and DUOX-2) and their redox-sensitive activator CED-10rac in stimulating vulva development. Thus, there are at least three genetically separable pathways by which ROS regulates vulval development.
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Affiliation(s)
| | - Ju-Ling Liu
- Department of Biology, McGill University, Montreal, Quebec, Canada
| | - David Desjardins
- Department of Biology, McGill University, Montreal, Quebec, Canada
| | - Ying Wang
- Department of Biology, McGill University, Montreal, Quebec, Canada
| | - Robyn Branicky
- Department of Biology, McGill University, Montreal, Quebec, Canada
| | - Siegfried Hekimi
- Department of Biology, McGill University, Montreal, Quebec, Canada
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12
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Mining for protein S-sulfenylation in Arabidopsis uncovers redox-sensitive sites. Proc Natl Acad Sci U S A 2019; 116:21256-21261. [PMID: 31578252 DOI: 10.1073/pnas.1906768116] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Hydrogen peroxide (H2O2) is an important messenger molecule for diverse cellular processes. H2O2 oxidizes proteinaceous cysteinyl thiols to sulfenic acid, also known as S-sulfenylation, thereby affecting the protein conformation and functionality. Although many proteins have been identified as S-sulfenylation targets in plants, site-specific mapping and quantification remain largely unexplored. By means of a peptide-centric chemoproteomics approach, we mapped 1,537 S-sulfenylated sites on more than 1,000 proteins in Arabidopsis thaliana cells. Proteins involved in RNA homeostasis and metabolism were identified as hotspots for S-sulfenylation. Moreover, S-sulfenylation frequently occurred on cysteines located at catalytic sites of enzymes or on cysteines involved in metal binding, hinting at a direct mode of action for redox regulation. Comparison of human and Arabidopsis S-sulfenylation datasets provided 155 conserved S-sulfenylated cysteines, including Cys181 of the Arabidopsis MITOGEN-ACTIVATED PROTEIN KINASE4 (AtMAPK4) that corresponds to Cys161 in the human MAPK1, which has been identified previously as being S-sulfenylated. We show that, by replacing Cys181 of recombinant AtMAPK4 by a redox-insensitive serine residue, the kinase activity decreased, indicating the importance of this noncatalytic cysteine for the kinase mechanism. Altogether, we quantitatively mapped the S-sulfenylated cysteines in Arabidopsis cells under H2O2 stress and thereby generated a comprehensive view on the S-sulfenylation landscape that will facilitate downstream plant redox studies.
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13
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Messina S, De Simone G, Ascenzi P. Cysteine-based regulation of redox-sensitive Ras small GTPases. Redox Biol 2019; 26:101282. [PMID: 31386964 PMCID: PMC6695279 DOI: 10.1016/j.redox.2019.101282] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 07/21/2019] [Accepted: 07/24/2019] [Indexed: 12/22/2022] Open
Abstract
Reactive oxygen and nitrogen species (ROS and RNS, respectively) activate the redox-sensitive Ras small GTPases. The three canonical genes (HRAS, NRAS, and KRAS) are archetypes of the superfamily of small GTPases and are the most common oncogenes in human cancer. Oncogenic Ras is intimately linked to redox biology, mainly in the context of tumorigenesis. The Ras protein structure is highly conserved, especially in effector-binding regions. Ras small GTPases are redox-sensitive proteins thanks to the presence of the NKCD motif (Asn116-Lys 117-Cys118-Asp119). Notably, the ROS- and RNS-based oxidation of Cys118 affects protein stability, activity, and localization, and protein-protein interactions. Cys residues at positions 80, 181, 184, and 186 may also help modulate these actions. Moreover, oncogenic mutations of Gly12Cys and Gly13Cys may introduce additional oxidative centres and represent actionable drug targets. Here, the pathophysiological involvement of Cys-redox regulation of Ras proteins is reviewed in the context of cancer and heart and brain diseases.
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Affiliation(s)
- Samantha Messina
- Department of Science, Roma Tre University, Viale Guglielmo Marconi 446, I-00146, Roma, Italy.
| | - Giovanna De Simone
- Department of Science, Roma Tre University, Viale Guglielmo Marconi 446, I-00146, Roma, Italy
| | - Paolo Ascenzi
- Department of Science, Roma Tre University, Viale Guglielmo Marconi 446, I-00146, Roma, Italy
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14
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Foo CHJ, Pervaiz S. gRASping the redox lever to modulate cancer cell fate signaling. Redox Biol 2019; 25:101094. [PMID: 30638892 PMCID: PMC6859584 DOI: 10.1016/j.redox.2018.101094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/22/2018] [Accepted: 12/26/2018] [Indexed: 01/17/2023] Open
Abstract
RAS proteins are critical regulators of signaling networks controlling diverse cellular functions such as cell proliferation and survival and its mutation are among the most powerful oncogenic drivers in human cancers. Despite intense efforts, direct RAS-targeting strategies remain elusive due to its "undruggable" nature. To that end, bulk of the research efforts has been directed towards targeting upstream and/or downstream of RAS signaling. However, the therapeutic efficacies of these treatments are limited in the long run due to the acquired drug resistance in RAS-driven cancers. Interestingly, recent studies have uncovered a potential role of RAS in redox-regulation as well as the interplay between ROS and RAS-associated signaling networks during process of cancer initiation and progression. More specifically, these studies provide ample evidence to implicate RAS as a redox-rheostat, manipulating ROS levels to provide a redox-milieu conducive for carcinogenesis. Importantly, the understanding of RAS-ROS interplay could provide us with novel targetable vulnerabilities for designing therapeutic strategies. In this review, we provide a brief summary of the advances in the field to illustrate the dual role of RAS in redox-regulation and its implications in RAS signaling outcomes and also emerging redox-based strategies to target RAS-driven cancers.
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Affiliation(s)
- Chuan Han Jonathan Foo
- Department of Physiology, YLL School of Medicine, National University of Singapore (NUS), Singapore; NUS Graduate School of Integrative Sciences and Engineering, NUS, Singapore
| | - Shazib Pervaiz
- Department of Physiology, YLL School of Medicine, National University of Singapore (NUS), Singapore; Medical Science Cluster Cancer Program, YLL School of Medicine, National University of Singapore (NUS), Singapore; NUS Graduate School of Integrative Sciences and Engineering, NUS, Singapore; National University Cancer Institute, NUHS, Singapore.
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15
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Ahearn I, Zhou M, Philips MR. Posttranslational Modifications of RAS Proteins. Cold Spring Harb Perspect Med 2018; 8:cshperspect.a031484. [PMID: 29311131 DOI: 10.1101/cshperspect.a031484] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The three human RAS genes encode four proteins that play central roles in oncogenesis by acting as binary molecular switches that regulate signaling pathways for growth and differentiation. Each is subject to a set of posttranslational modifications (PTMs) that modify their activity or are required for membrane targeting. The enzymes that catalyze the various PTMs are potential targets for anti-RAS drug discovery. The PTMs of RAS proteins are the focus of this review.
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Affiliation(s)
- Ian Ahearn
- Department of Medicine, Perlmutter Cancer Center, New York University School of Medicine, New York, New York 10016
| | - Mo Zhou
- Department of Medicine, Perlmutter Cancer Center, New York University School of Medicine, New York, New York 10016
| | - Mark R Philips
- Department of Medicine, Perlmutter Cancer Center, New York University School of Medicine, New York, New York 10016
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16
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Rizza S, Filomeni G. Role, Targets and Regulation of (de)nitrosylation in Malignancy. Front Oncol 2018; 8:334. [PMID: 30234010 PMCID: PMC6131587 DOI: 10.3389/fonc.2018.00334] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/02/2018] [Indexed: 12/27/2022] Open
Affiliation(s)
- Salvatore Rizza
- Redox Signaling and Oxidative Stress Research Group, Cell Stress and Survival Unit, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center, Copenhagen, Denmark
| | - Giuseppe Filomeni
- Redox Signaling and Oxidative Stress Research Group, Cell Stress and Survival Unit, Center for Autophagy, Recycling and Disease, Danish Cancer Society Research Center, Copenhagen, Denmark.,Department of Biology, University of Rome Tor Vergata, Rome, Italy
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Nakhaei-Rad S, Haghighi F, Nouri P, Rezaei Adariani S, Lissy J, Kazemein Jasemi NS, Dvorsky R, Ahmadian MR. Structural fingerprints, interactions, and signaling networks of RAS family proteins beyond RAS isoforms. Crit Rev Biochem Mol Biol 2018; 53:130-156. [PMID: 29457927 DOI: 10.1080/10409238.2018.1431605] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Saeideh Nakhaei-Rad
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Fereshteh Haghighi
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Parivash Nouri
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Soheila Rezaei Adariani
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Jana Lissy
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Neda S Kazemein Jasemi
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Radovan Dvorsky
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
| | - Mohammad Reza Ahmadian
- a Institute of Biochemistry and Molecular Biology II, Medical Faculty , Heinrich-Heine University , Düsseldorf , Germany
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18
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Kim J, Choi S, Saxena N, Singh AK, Singh I, Won JS. Regulation of STAT3 and NF-κB activations by S-nitrosylation in multiple myeloma. Free Radic Biol Med 2017; 106:245-253. [PMID: 28232202 PMCID: PMC5826580 DOI: 10.1016/j.freeradbiomed.2017.02.039] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 02/09/2017] [Accepted: 02/20/2017] [Indexed: 10/20/2022]
Abstract
Numerous reports suggest that aberrant activations of STAT3 and NF-κB promote survival and proliferation of multiple myeloma (MM) cells. In the present report, we demonstrate that a synthetic S-nitrosothiol compound, S-nitroso-N-acetylcysteine (SNAC), inhibits proliferation and survival of multiple MM cells via S-nitrosylation-dependent inhibition of STAT3 and NF-κB. In human MM cells (e.g. U266, H929, and IM-9 cells), SNAC treatment increased S-nitrosylation of STAT3 and NF-κB and inhibited their activities. Consequently, SNAC treatment resulted in MM cell cycle arrest at G1/S check point and inhibited their proliferation. SNAC also decreased the expression of cell survival factors and increased the activities of caspases, thus increased sensitivity of MM cells to melphalan, a chemotherapeutic agent for MM. In U266 xenografted mice, SNAC treatment decreased the activity of STAT3 and reduced the growth of human CD138 positive cells (U266 cells) in the bone marrow and also reduced their production of human IgE into the serum. Taken together, these data document the S-nitrosylation mediated inhibition of MM cell proliferation and cell survival via inhibition of STAT3 and NF-κB pathways and its efficacy in animal model of MM.
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Affiliation(s)
- Jinsu Kim
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Seungho Choi
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Nishant Saxena
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Avtar K Singh
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29425, United States; Pathology and Laboratory Medicine Service, Ralph H. Johnson Veterans Administration Medical Center, Charleston, SC 29401, United States
| | - Inderjit Singh
- Department of Pediatrics, Medical University of South Carolina, Charleston, SC 29425, United States.
| | - Je-Seong Won
- Department of Pathology and Laboratory Medicine, Medical University of South Carolina, Charleston, SC 29425, United States.
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19
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Montagna C, Rizza S, Maiani E, Piredda L, Filomeni G, Cecconi F. To eat, or NOt to eat: S-nitrosylation signaling in autophagy. FEBS J 2016; 283:3857-3869. [PMID: 27083138 DOI: 10.1111/febs.13736] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/14/2016] [Accepted: 04/08/2016] [Indexed: 12/15/2022]
Abstract
Autophagy is the main catabolic cellular process through which cells adapt their needs (e.g., growth and proliferation) to environmental availability of nutrients (e.g., amino acid and glucose) and growth factors. The rapid activation of the autophagy response essentially depends on protein post-translational modifications (PTMs), which act as molecular switches triggering signaling cascades. Deregulation of autophagy contributes to pathological conditions, such as cancer and neurodegeneration. Therefore, understanding how PTMs affect the occurrence of autophagy is of the highest importance for clinical applications. Besides phosphorylation and ubiquitylation, which represent the best known examples of PTMs, redox-based modifications are also emerging as contributing to the regulation of intracellular signaling. Of note, S-nitrosylation of cysteine residues is a redox PTM and is the principal mechanism of nitric oxide-based signaling. Results emerging in recent years suggest that NO has a role in modulating autophagy. However, the function of S-nitrosylation in autophagy regulation remains still unveiled. By this review, we describe the upstream events regulating autophagy activation focusing on recently published evidence implying a S-nitrosylation-dependent regulation.
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Affiliation(s)
| | | | | | - Lucia Piredda
- Department of Biology, University of Rome Tor Vergata, Italy
| | - Giuseppe Filomeni
- Danish Cancer Society Research Center, Copenhagen, Denmark.,Department of Biology, University of Rome Tor Vergata, Italy
| | - Francesco Cecconi
- Danish Cancer Society Research Center, Copenhagen, Denmark.,Department of Biology, University of Rome Tor Vergata, Italy.,IRCCS Fondazione Santa Lucia, Rome, Italy
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20
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ERK1/2-induced phosphorylation of R-Ras GTPases stimulates their oncogenic potential. Oncogene 2016; 35:5692-5698. [PMID: 27086924 DOI: 10.1038/onc.2016.122] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 03/02/2016] [Accepted: 03/07/2016] [Indexed: 12/14/2022]
Abstract
The Ras-related (R-Ras) isoforms TC21, R-Ras and M-Ras are members of the Ras superfamily of small GTPases. R-Ras family proteins are frequently overexpressed in human cancers, and expression of activated mutants of these GTPases is sufficient to induce cell transformation. Unlike Ras, few activating mutations of R-Ras proteins have been reported in human cancer, and very little is known about the regulation of their activity. In this study, we report that TC21 and R-Ras are phosphorylated on a conserved serine, Ser186 and Ser201, respectively, in intact cells. This residue is located in the C-terminal hypervariable region of the proteins and is not conserved in M-Ras. We show that the MAP kinases ERK1/2 phosphorylate TC21 and R-Ras on this C-terminal serine residue both in vitro and in vivo. Phosphorylation of R-Ras proteins does not affect their subcellular localization or stability but rather stimulates their activation. Phosphorylation-defective mutants of R-Ras and TC21 are compromised in their ability to promote cancer cell adhesion and migration/invasion, respectively. Importantly, we show that phosphorylation of TC21 and R-Ras potentiates their tumorigenic activity in immunodeficient mice. Our results identify a novel regulatory mechanism of the small GTPases TC21 and R-Ras that controls their oncogenic potential.
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21
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Wang YJ, Dong YX, Wang J, Cui XM. Alleviating effects of exogenous NO on tomato seedlings under combined Cu and Cd stress. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2016; 23:4826-36. [PMID: 26545885 DOI: 10.1007/s11356-015-5525-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 10/01/2015] [Indexed: 05/10/2023]
Abstract
To investigate the effect of NO on the different origin and regulation of oxidative stress of Cu and/or Cd, tomato seedlings were treated with Cu, Cd, or Cu + Cd in a nutrient solution culture system. The main effect of Cu(2+) was a significant reduction in root activity and nitrate reductase (NR) activity, which was similar to that under 50 μM Cd treatment, but promoted Cu accumulation. The supply of Cu under Cd treatment decreased Cd concentration, while not altered Cu concentration by contrast with Cu treatment, which is suggestive of a replacement of Cu(2+) with Cd(2+) and effective decrease in the boiotoxicity of 50 μM Cd(2+) to tomato seedlings. However, NO alleviated the restriction to NR activity significantly and made the biomass of tomato seedlings recover under Cd treatment, and also increased root activity under Cu and Cu + Cd treatment. Exogenous NO markedly reduced the absorption and transportation of Cu but did not obviously change the translocation of Cd to the aboveground parts under Cu + Cd treatment. Both metals induced lipid peroxidation via the decreasing activation of antioxidant enzymes. The antioxidant enzyme system worked differently under Cu, Cd, or Cu + Cd stress. The activities of peroxidase (POD) and catalase (CAT) were higher under single Cd stress than under the control. Meanwhile, Cu + Cd treatment decreased the activities of POD, superoxide dismutase (SOD), and ascorbic acid peroxidase (APX). Exogenous NO increased POD and SOD activities in the leaves and roots, and CAT activity in the roots under combined Cu and Cd stress. These results suggest that a different response and regulation mechanism that involves exogenous NO is present in tomato seedlings under Cu and Cd stress.
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Affiliation(s)
- Yi-Jun Wang
- National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Tai'an, China
| | - Yu-Xiu Dong
- College of Life Sciences, Shandong Agricultural University, Tai'an, China
| | - Juan Wang
- Department of Landscape Engineering, Heze University, Heze, China
| | - Xiu-Min Cui
- National Engineering Laboratory for Efficient Utilization of Soil and Fertilizer Resources, College of Resources and Environment, Shandong Agricultural University, Tai'an, China.
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22
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Nicolas F, Wu C, Bukhari S, de Toledo SM, Li H, Shibata M, Azzam EI. S-Nitrosylation in Organs of Mice Exposed to Low or High Doses of γ-Rays: The Modulating Effect of Iodine Contrast Agent at a Low Radiation Dose. Proteomes 2015; 3:56-73. [PMID: 26317069 PMCID: PMC4548934 DOI: 10.3390/proteomes3020056] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The covalent addition of nitric oxide (NO•) onto cysteine thiols, or S-nitrosylation, modulates the activity of key signaling proteins. The dysregulation of normal S-nitrosylation contributes to degenerative conditions and to cancer. To gain insight into the biochemical changes induced by low-dose ionizing radiation, we determined global S-nitrosylation by the “biotin switch” assay coupled with mass spectrometry analyses in organs of C57BL/6J mice exposed to acute 0.1 Gy of 137Cs γ-rays. The dose of radiation was delivered to the whole body in the presence or absence of iopamidol, an iodinated contrast agent used during radiological examinations. To investigate whether similar or distinct nitrosylation patterns are induced following high-dose irradiation, mice were exposed in parallel to acute 4 Gy of 137Cs γ rays. Analysis of modulated S-nitrosothiols (SNO-proteins) in freshly-harvested organs of animals sacrificed 13 days after irradiation revealed radiation dose- and contrast agent-dependent changes. The major results were as follows: (i) iopamidol alone had significant effects on S-nitrosylation in brain, lung and liver; (ii) relative to the control, exposure to 0.1 Gy without iopamidol resulted in statistically-significant SNO changes in proteins that differ in molecular weight in liver, lung, brain and blood plasma; (iii) iopamidol enhanced the decrease in S-nitrosylation induced by 0.1 Gy in brain; (iv) whereas a decrease in S-nitrosylation occurred at 0.1 Gy for proteins of ~50 kDa in brain and for proteins of ~37 kDa in liver, an increase was detected at 4 Gy in both organs; (v) mass spectrometry analyses of nitrosylated proteins in brain revealed differential modulation of SNO proteins (e.g., sodium/potassium-transporting ATPase subunit beta-1; beta tubulins; ADP-ribosylation factor 5) by low- and high-dose irradiation; and (vi) ingenuity pathway analysis identified major signaling networks to be modulated, in particular the neuronal nitric oxide synthase signaling pathway was differentially modulated by low- and high-dose γ-irradiation.
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Affiliation(s)
- Fadia Nicolas
- Department of Health Informatics, Rutgers School of Health Related Professions, Newark, NJ 07107, USA; E-Mail:
| | - Changgong Wu
- Department of Biochemistry and Molecular Biology, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; E-Mail:
| | - Salwa Bukhari
- Department of Radiology, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; E-Mail:
| | - Sonia M. de Toledo
- Department of Radiology, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; E-Mail:
| | - Hong Li
- Department of Biochemistry and Molecular Biology, Rutgers New Jersey Medical School, Newark, NJ 07103, USA; E-Mail:
| | - Masayuki Shibata
- Department of Health Informatics, Rutgers School of Health Related Professions, Newark, NJ 07107, USA
- Authors to whom correspondence should be addressed; E-Mails: (M.S.); (E.I.A.); Tel.: +1-973-972-5323 (E.I.A.); Fax: +1-973-972-1865 (E.I.A.)
| | - Edouard I. Azzam
- Department of Radiology, RUTGERS New Jersey Medical School, Newark, NJ 07103, USA
- Authors to whom correspondence should be addressed; E-Mails: (M.S.); (E.I.A.); Tel.: +1-973-972-5323 (E.I.A.); Fax: +1-973-972-1865 (E.I.A.)
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Reduced HRAS G12V-Driven Tumorigenesis of Cell Lines Expressing KRAS C118S. PLoS One 2015; 10:e0123918. [PMID: 25902334 PMCID: PMC4406447 DOI: 10.1371/journal.pone.0123918] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 03/09/2015] [Indexed: 11/19/2022] Open
Abstract
In many different human cancers, one of the HRAS, NRAS, or KRAS genes in the RAS family of small GTPases acquires an oncogenic mutation that renders the encoded protein constitutively GTP-bound and thereby active, which is well established to promote tumorigenesis. In addition to oncogenic mutations, accumulating evidence suggests that the wild-type isoforms may also be activated and contribute to oncogenic RAS-driven tumorigenesis. In this regard, redox-dependent reactions with cysteine 118 (C118) have been found to promote activation of wild-type HRAS and NRAS. We sought to determine if this residue is also important for the activation of wild-type KRAS and promotion of tumorigenesis. Thus, we mutated C118 to serine (C118S) in wild-type KRAS to block redox-dependent reactions at this site. We now report that this mutation reduced the level of GTP-bound KRAS and impaired RAS signaling stimulated by the growth factor EGF. With regards to tumorigenesis, we also report that oncogenic HRAS-transformed human cells in which endogenous KRAS was knocked down and replaced with KRASC118S exhibited reduced xenograft tumor growth, as did oncogenic HRAS-transformed KrasC118S/C118S murine cells in which the C118S mutation was knocked into the endogenous Kras gene. Taken together, these data suggest a role for redox-dependent activation of wild-type KRAS through C118 in oncogenic HRAS-driven tumorigenesis.
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24
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Abstract
The coordination chemistry of metal nitrosyls has expanded rapidly in the past decades due to major advances of nitric oxide and its metal compounds in biology. This review article highlights advances made in the area of multinuclear metal nitrosyl complexes, including Roussin's salts and their ester derivatives from 2003 to present. The review article focuses on isolated multinuclear metal nitrosyl complexes and is organized into different sections by the number of metal centers and bridging ligands.
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25
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Huang L, Carney J, Cardona DM, Counter CM. Decreased tumorigenesis in mice with a Kras point mutation at C118. Nat Commun 2014; 5:5410. [PMID: 25394415 PMCID: PMC4234187 DOI: 10.1038/ncomms6410] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 09/29/2014] [Indexed: 02/04/2023] Open
Abstract
KRAS, NRAS, or HRAS genes are mutated to encode an active oncogenic protein in a quarter of human cancers. Redox-dependent reactions can also lead to Ras activation in a manner dependent upon the thiol residue of cysteine 118 (C118). Here, to investigate the effect of mutating this residue on tumorigenesis, we introduce a C118S mutation into the endogenous murine Kras allele and expose the resultant mice to the carcinogen urethane, which induces Kras mutation-positive lung tumors. We report that Kras+/C118S and KrasC118S/C118S mice develop fewer lung tumors. Although the KrasC118S allele does not appear to affect tumorigenesis when the remaining Kras allele is conditionally oncogenic, there is a moderate imbalance of oncogenic mutations favoring the native Kras allele in tumors from Kras+/C118S mice treated with urethane. We conclude that the KrasC118S allele impedes urethane-induced lung tumorigenesis.
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Affiliation(s)
- Lu Huang
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - John Carney
- Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Diana M Cardona
- Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, USA
| | - Christopher M Counter
- 1] Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA [2] Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina 27710, USA
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26
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Iyer AKV, Rojanasakul Y, Azad N. Nitrosothiol signaling and protein nitrosation in cell death. Nitric Oxide 2014; 42:9-18. [PMID: 25064181 DOI: 10.1016/j.niox.2014.07.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2013] [Revised: 06/01/2014] [Accepted: 07/10/2014] [Indexed: 10/25/2022]
Abstract
Nitric oxide, a reactive free radical, is an important signaling molecule that can lead to a plethora of cellular effects affecting homeostasis. A well-established mechanism by which NO manifests its effect on cellular functions is the post-translational chemical modification of cysteine thiols in substrate proteins by a process known as S-nitrosation. Studies that investigate regulation of cellular functions through NO have increasingly established S-nitrosation as the primary modulatory mechanism in their respective systems. There has been a substantial increase in the number of reports citing various candidate proteins undergoing S-nitrosation, which affects cell-death and -survival pathways in a number of tissues including heart, lung, brain and blood. With an exponentially growing list of proteins being identified as substrates for S-nitrosation, it is important to assimilate this information in different cell/tissue systems in order to gain an overall view of protein regulation of both individual proteins and a class of protein substrates. This will allow for broad mapping of proteins as a function of S-nitrosation, and help delineate their global effects on pathophysiological responses including cell death and survival. This information will not only provide a much better understanding of overall functional relevance of NO in the context of various disease states, it will also facilitate the generation of novel therapeutics to combat specific diseases that are driven by NO-mediated S-nitrosation.
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Affiliation(s)
| | - Yon Rojanasakul
- Department of Pharmaceutical Sciences, West Virginia University, Morgantown, WV 26505, USA
| | - Neelam Azad
- Department of Pharmaceutical Sciences, Hampton University, Hampton, VA 23668, USA
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27
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Wolff G, Balke JE, Andras IE, Park M, Toborek M. Exercise modulates redox-sensitive small GTPase activity in the brain microvasculature in a model of brain metastasis formation. PLoS One 2014; 9:e97033. [PMID: 24804765 PMCID: PMC4013134 DOI: 10.1371/journal.pone.0097033] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Accepted: 04/14/2014] [Indexed: 12/26/2022] Open
Abstract
Tumor cell extravasation into the brain requires passage through the blood-brain barrier (BBB). There is evidence that exercise can alter the oxidation status of the brain microvasculature and protect against tumor cell invasion into the brain, although the mechanisms are not well understood. In the current study, we focused on the role of microenvironment generated by exercise and metastasizing tumor cells at the levels of brain microvessels, influencing oxidative stress-mediated responses and activation of redox-sensitive small GTPases. Mature male mice were exercised for four weeks using a running wheel with the average voluntary running distance 9.0 ± 0.3 km/day. Mice were then infused with 1.0 × 10(6) D122 (murine Lewis lung carcinoma) cells into the brain microvasculature, and euthanized either 48 hours (in short-term studies) or 2-3 weeks (in long-term studies) post tumor cell administration. A significant increase in the level of reactive oxygen species was observed following 48 hours or 3 weeks of tumor cells growth, which was accompanied by a reduction in MnSOD expression in the exercised mice. Activation of the small GTPase Rho was negatively correlated with running distance in the tumor cell infused mice. Together, these data suggest that exercise may play a significant role during aggressive metastatic invasion, especially at higher intensities in pre-trained individuals.
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Affiliation(s)
- Gretchen Wolff
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida, United States of America
| | - Jordan E. Balke
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida, United States of America
| | - Ibolya E. Andras
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida, United States of America
| | - Minseon Park
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida, United States of America
| | - Michal Toborek
- Department of Biochemistry and Molecular Biology, University of Miami School of Medicine, Miami, Florida, United States of America
- Jerzy Kukuczka Academy of Physical Education, Katowice, Poland
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Wey M, Phan V, Yepez G, Heo J. Superoxide inhibits guanine nucleotide exchange factor (GEF) action on Ras, but not on Rho, through desensitization of Ras to GEF. Biochemistry 2014; 53:518-32. [PMID: 24422478 PMCID: PMC4327825 DOI: 10.1021/bi401528n] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Ras and Rho GTPases are molecular switches for various vital cellular signaling pathways. Overactivation of these GTPases often causes development of cancer. Guanine nucleotide exchange factors (GEFs) and oxidants function to upregulate these GTPases through facilitation of guanine nucleotide exchange (GNE) of these GTPases. However, the effect of oxidants on GEF functions, or vice versa, has not been known. We show that, via targeting Ras Cys(51), an oxidant inhibits the catalytic action of Cdc25-the catalytic domain of RasGEFs-on Ras. However, the enhancement of Ras GNE by an oxidant continues regardless of the presence of Cdc25. Limiting RasGEF action by an oxidant may function to prevent the pathophysiological overactivation of Ras in the presence of both RasGEFs and oxidants. The continuous exposure of Ras to nitric oxide and its derivatives can form S-nitrosated Ras (Ras-SNO). This study also shows that an oxidant not only inhibits the catalytic action of Cdc25 on Ras-SNO but also fails to enhance Ras-SNO GNE. This lack of enhancement then populates the biologically inactive Ras-SNO in cells, which may function to prevent the continued redox signaling of the Ras pathophysiological response. Finally, this study also demonstrates that, unlike the case with RasGEFs, an oxidant does not inhibit the catalytic action of RhoGEF-Vav or Dbs-on Rho GTPases such as Rac1, RhoA, RhoC, and Cdc42. This result explains the results of the previous study in which, despite the presence of an oxidant, the catalytic action of Dbs in cells continued to enhance RhoC GNE.
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Affiliation(s)
- Michael Wey
- Department of Chemistry and Biochemistry, The University of Texas at Arlington , Arlington, Texas 76019, United States
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Abstract
Redox agents have been historically considered pathological agents which can react with and damage many biological macromolecules including DNA, proteins, and lipids. However, a growing number of reports have suggested that mammalian cells can rapidly respond to ligand stimulation with a change in intracellular ROS thus indicating that the production of intracellular redox agents is tightly regulated and that they serve as intracellular signaling molecules being involved in a variety of cell signaling pathways. Numerous observations have suggested that some members of the Ras GTPase superfamily appear to regulate the production of redox agents and that oxidants can function as effector molecules for the small GTPases, thus contributing to their overall biological function. In addition, many of the Ras superfamily small GTPases have been shown to be redox sensitive, thanks to the presence of redox-sensitive sequences in their primary structure. The action of redox agents on these redox-sensitive GTPases is similar to that of guanine nucleotide exchange factors in that they perturb GTPase nucleotide-binding interactions that result in the enhancement of the guanine nucleotide exchange of small GTPases. Thus, Ras GTPases may act both as upstream regulators and downstream effectors of redox agents. Here we overview current understanding concerning the interplay between Ras GTPases and redox agents, also taking into account pathological implications of misregulation of this cross talk and highlighting the potentiality of these cellular pathways as new therapeutical targets for different pathologies.
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Hobbs GA, Gunawardena HP, Campbell SL. Biophysical and proteomic characterization strategies for cysteine modifications in Ras GTPases. Methods Mol Biol 2014; 1120:75-96. [PMID: 24470020 DOI: 10.1007/978-1-62703-791-4_6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cysteine is one of the most reactive amino acids and is modified by a number of oxidants. The reactivity of cysteines is dependent on the thiol pK a; however, measuring cysteine pK a values is nontrivial. Ras family GTPases have been shown to contain a free cysteine that is sensitive to oxidation, and free radical-mediated oxidation of this cysteine has been shown to be activating. Here, we present a new technique that allows for measuring cysteine pK a values using a fluorescent detection system with the molecule 4-fluoro-7-aminosulfonylbenzofurazan (ABD-F). In addition, we also describe how to generate several oxidants. Lastly, we describe several mass spectrometry-based experiments and the necessary adjustments to the experiments to detect cysteine oxidation.
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Affiliation(s)
- G Aaron Hobbs
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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Ko ML, Shi L, Huang CCY, Grushin K, Park SY, Ko GYP. Circadian phase-dependent effect of nitric oxide on L-type voltage-gated calcium channels in avian cone photoreceptors. J Neurochem 2013; 127:314-28. [PMID: 23895452 DOI: 10.1111/jnc.12384] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Revised: 07/19/2013] [Accepted: 07/25/2013] [Indexed: 12/20/2022]
Abstract
Nitric oxide (NO) plays an important role in phase-shifting of circadian neuronal activities in the suprachiasmatic nucleus and circadian behavior activity rhythms. In the retina, NO production is increased in a light-dependent manner. While endogenous circadian oscillators in retinal photoreceptors regulate their physiological states, it is not clear whether NO also participates in the circadian regulation of photoreceptors. In this study, we demonstrate that NO is involved in the circadian phase-dependent regulation of L-type voltage-gated calcium channels (L-VGCCs). In chick cone photoreceptors, the L-VGCCα1 subunit expression and the maximal L-VGCC currents are higher at night, and both Ras-mitogen-activated protein kinase (MAPK)-extracellular signal-regulated kinase (Erk) and Ras-phosphatidylinositol 3 kinase (PI3K)-protein kinase B (Akt) are part of the circadian output pathways regulating L-VGCCs. The NO-cGMP-protein kinase G (PKG) pathway decreases L-VGCCα1 subunit expression and L-VGCC currents at night, but not during the day, and exogenous NO donor or cGMP decreases the phosphorylation of Erk and Akt at night. The protein expression of neural NO synthase (nNOS) is also under circadian control, with both nNOS and NO production being higher during the day. Taken together, NO/cGMP/PKG signaling is involved as part of the circadian output pathway to regulate L-VGCCs in cone photoreceptors. In cone photoreceptors, the protein expression of neural nitric oxide synthase (nNOS) and NO production are under circadian control. NO-cGMP-protein kinase G (PKG) signaling serves in the circadian output pathway to regulate the circadian rhythms of L-type voltage-gated calcium channels (L-VGCCs) in part through regulating the phosphorylation states of extracellular-signal-regulated kinase (Erk) and protein kinase B (Akt).
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Affiliation(s)
- Michael L Ko
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
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Holloway LR, Li L. The Preparation, Structural Characteristics, and Physical Chemical Properties of Metal-Nitrosyl Complexes. STRUCTURE AND BONDING 2013; 154:53-98. [PMID: 29398732 PMCID: PMC5792085 DOI: 10.1007/430_2013_101] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The preparation and characterization of a representative group of novel non-heme metal nitrosyl complexes that have been synthesized over the last decade are discussed here. Their structures are examined and classified based on metal type, the number of metal centers present, and the type of ligand that is coordinated with the metal. The ligands can be phosphorus, nitrogen, or sulfur based (with a few exceptions) and can vary depending on the presence of chelation, intermolecular forces, or the presence of other ligands. Structural and bonding characteristics are summarized and examples of reactivity regarding nitrosyl ligands are given. Some of the relevant physical chemical properties of these complexes, including IR, EPR, NMR, UV-vis, cyclic voltammetry, and X-ray crystallography are examined.
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Affiliation(s)
- Lauren R Holloway
- Department of Chemistry and Biochemistry, California State University, 1250 Bellflower Boulevard, Long Beach, CA 90840, USA
| | - Lijuan Li
- Department of Chemistry and Biochemistry, California State University, 1250 Bellflower Boulevard, Long Beach, CA 90840, USA
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Hobbs GA, Bonini MG, Gunawardena HP, Chen X, Campbell SL. Glutathiolated Ras: characterization and implications for Ras activation. Free Radic Biol Med 2013; 57:221-9. [PMID: 23123410 PMCID: PMC3985386 DOI: 10.1016/j.freeradbiomed.2012.10.531] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/05/2012] [Accepted: 10/08/2012] [Indexed: 01/02/2023]
Abstract
Ras GTPases cycle between active GTP-bound and inactive GDP-bound forms to regulate a multitude of cellular processes, including cell growth, differentiation, and apoptosis. The activation state of Ras is regulated by protein modulatory agents that accelerate the slow intrinsic rates of GDP dissociation and GTP hydrolysis. Similar to the action of guanine-nucleotide exchange factors, the rate of GDP dissociation can be greatly enhanced by the reaction of Ras with small-molecule redox agents, such as nitrogen dioxide, which can promote Ras activation. Nitrogen dioxide is an autoxidation product of nitric oxide and can react with an accessible cysteine of Ras to cause oxidation of the bound guanine nucleotide to facilitate Ras guanine nucleotide dissociation. Glutathione has also been reported to modify Ras and alter its activity. To elucidate the mechanism by which glutathione alters Ras guanine nucleotide binding properties, we performed NMR, top-down and bottom-up mass spectrometry, and biochemical analyses of glutathiolated Ras. We determined that treatment of H-Ras, lacking the nonconserved hypervariable region, with oxidized glutathione results in glutathiolation specifically at cysteine 118. However, glutathiolation does not alter Ras structure or biochemical properties. Rather, changes in guanine nucleotide binding properties and Ras activity occur upon exposure of Ras to free radicals, presumably through the generation of a cysteine 118 thiyl radical. Interestingly, Ras glutathiolation protects Ras from further free radical-mediated activation events. Therefore, glutathiolation does not affect Ras activity unless Ras is modified by glutathione through a radical-mediated mechanism.
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Affiliation(s)
- G Aaron Hobbs
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599, USA
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Wong BS, Lam KK, Lee CL, Wong VH, Lam MP, Chu IK, Yeung WS, Chiu PC. Adrenomedullin Enhances Invasion of Human Extravillous Cytotrophoblast-Derived Cell Lines by Regulation of Urokinase Plasminogen Activator Expression and S-Nitrosylation1. Biol Reprod 2013; 88:34. [DOI: 10.1095/biolreprod.112.103903] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
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Mitchell L, Hobbs GA, Aghajanian A, Campbell SL. Redox regulation of Ras and Rho GTPases: mechanism and function. Antioxid Redox Signal 2013; 18:250-8. [PMID: 22657737 PMCID: PMC3518547 DOI: 10.1089/ars.2012.4687] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
SIGNIFICANCE Oxidation and reduction events are critical to physiological and pathological processes and are highly regulated. Herein, we present evidence for the role of Ras and Rho GTPases in controlling these events and the unique underlying mechanisms. Evidence for redox regulation of Ras GTPases that contain a redox-sensitive cysteine (X) in the conserved NKXD motif is presented, and a growing consensus supports regulation by a thiyl radical-mediated oxidation mechanism. We also discuss the debate within the literature regarding whether 2e(-) oxidation mechanisms also regulate Ras GTPase activity. RECENT ADVANCES We examine the increasing in vitro and cell-based data supporting oxidant-mediated activation of Rho GTPases that contain a redox-sensitive cysteine at the end of the conserved phosphoryl-binding loop (p-loop) motif (GXXXXG[S/T]C). While this motif is distinct from Ras, these data suggest a similar 1e(-) oxidation-mediated activation mechanism. CRITICAL ISSUES We also review the data showing that the unique p-loop placement of the redox-sensitive cysteine in Rho GTPases supports activation by 2e(-) cysteine oxidation. Finally, we examine the role that Ras and Rho GTPases play in controlling key oxidant-regulating enzymes in the cell, and we speculate on a feedback mechanism. FUTURE DIRECTIONS Given that these GTPases and redox-regulating enzymes are involved in multiple physiological and pathological processes, we discuss future experiments that may clarify the interplay between them.
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Affiliation(s)
- Lauren Mitchell
- Department of Biochemistry and Biophysics, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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36
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Davis MF, Zhou L, Ehrenshaft M, Ranguelova K, Gunawardena HP, Chen X, Bonini M, Mason RP, Campbell SL. Detection of Ras GTPase protein radicals through immuno-spin trapping. Free Radic Biol Med 2012; 53:1339-45. [PMID: 22819983 PMCID: PMC3549333 DOI: 10.1016/j.freeradbiomed.2012.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 06/27/2012] [Accepted: 07/10/2012] [Indexed: 01/05/2023]
Abstract
Over the past decade immuno-spin trapping (IST) has been used to detect and identify protein radical sites in numerous heme and metalloproteins. To date, however, the technique has had little application toward nonmetalloproteins. In this study, we demonstrate the successful application of IST in a system free of transition metals and present the first conclusive evidence of (•)NO-mediated protein radical formation in the HRas GTPase. HRas is a nonmetalloprotein that plays a critical role in regulating cell-growth control. Protein radical formation in Ras GTPases has long been suspected of initiating premature release of bound guanine nucleotide. This action results in altered Ras activity both in vitro and in vivo. As described herein, successful application of IST may provide a means for detecting and identifying radical-mediated Ras activation in many different cancers and disease states in which Ras GTPases play an important role.
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Affiliation(s)
- Michael F. Davis
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599
| | - Li Zhou
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599
| | - Marilyn Ehrenshaft
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, P.O. Box 12233, MD F0-01, 111 T. W. Alexander Drive, Research Triangle Park, North Carolina 27709
| | - Kalina Ranguelova
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, P.O. Box 12233, MD F0-01, 111 T. W. Alexander Drive, Research Triangle Park, North Carolina 27709
| | - Harsha P. Gunawardena
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599
| | - Xian Chen
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599
| | - Marcelo Bonini
- UIC Section of Cardiology, University of Illinois at Chicago, Chicago IL 60612
| | - Ronald P. Mason
- Laboratory of Toxicology and Pharmacology, National Institute of Environmental Health Sciences, P.O. Box 12233, MD F0-01, 111 T. W. Alexander Drive, Research Triangle Park, North Carolina 27709
| | - Sharon L. Campbell
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599
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37
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Bátor J, Varga J, Berta G, Barbakadze T, Mikeladze D, Ramsden J, Szeberényi J. Sodium nitroprusside, a nitric oxide donor, fails to bypass the block of neuronal differentiation in PC12 cells imposed by a dominant negative Ras protein. Cell Mol Biol Lett 2012; 17:323-32. [PMID: 22491983 PMCID: PMC6275566 DOI: 10.2478/s11658-012-0013-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Accepted: 03/27/2012] [Indexed: 12/02/2022] Open
Abstract
Nitric oxide (NO) is a mediator of a diverse array of inter- and intracellular signal transduction processes. The aim of the present study was to analyze its possible role as a second messenger in the process of neuronal differentiation of PC12 pheochromocytoma cells. Upon NGF treatment wildtype PC12 cells stop dividing and develop neurites. In contrast, a PC12 subclone (designated M-M17-26) expressing a dominant-negative mutant Ras protein keeps proliferating and fails to grow neurites after NGF treatment. Sodium nitroprusside (SNP), an NO donor, was found to induce the p53 protein and to inhibit proliferation of both PC12 and M-M17-26 cells, but failed to induce neuronal differentiation in these cell lines. Key signaling pathways (the ERK and Akt pathways) were also not affected by SNP treatment, and the phosphorylation of CREB transcription factor was only slightly stimulated. It is thus concluded from the results presented in this paper that NO is unable to activate signaling proteins acting downstream or independent of Ras that are required for neuronal differentiation.
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Affiliation(s)
- Judit Bátor
- Department of Medical Biology, Medical School, University of Pécs, 7624 Pécs, Szigeti u. 12, Hungary
| | - Judit Varga
- Department of Medical Biology, Medical School, University of Pécs, 7624 Pécs, Szigeti u. 12, Hungary
| | - Gergely Berta
- Department of Medical Biology, Medical School, University of Pécs, 7624 Pécs, Szigeti u. 12, Hungary
| | | | | | - Jeremy Ramsden
- Collegium Basilea, Institute of Advanced Study, Basel, Switzerland
| | - József Szeberényi
- Department of Medical Biology, Medical School, University of Pécs, 7624 Pécs, Szigeti u. 12, Hungary
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Ahearn IM, Haigis K, Bar-Sagi D, Philips MR. Regulating the regulator: post-translational modification of RAS. Nat Rev Mol Cell Biol 2011; 13:39-51. [PMID: 22189424 PMCID: PMC3879958 DOI: 10.1038/nrm3255] [Citation(s) in RCA: 402] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
RAS proteins are monomeric GTPases that act as binary molecular switches to regulate a wide range of cellular processes. The exchange of GTP for GDP on RAS is regulated by guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs), which regulate the activation state of RAS without covalently modifying it. By contrast, post-translational modifications (PTMs) of RAS proteins direct them to various cellular membranes and, in some cases, modulate GTP-GDP exchange. Important RAS PTMs include the constitutive and irreversible remodelling of its carboxy-terminal CAAX motif by farnesylation, proteolysis and methylation, reversible palmitoylation, and conditional modifications, including phosphorylation, peptidyl-prolyl isomerisation, monoubiquitylation, diubiquitylation, nitrosylation, ADP ribosylation and glucosylation.
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Affiliation(s)
- Ian M Ahearn
- NYU School of Medicine, 550 First Avenue, New York, NY 10016, USA
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The Interplay between ROS and Ras GTPases: Physiological and Pathological Implications. JOURNAL OF SIGNAL TRANSDUCTION 2011; 2012:365769. [PMID: 22175014 PMCID: PMC3235814 DOI: 10.1155/2012/365769] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 10/18/2011] [Indexed: 01/23/2023]
Abstract
The members of the RasGTPase superfamily are involved in various signaling networks responsible for fundamental cellular processes. Their activity is determined by their guanine nucleotide-bound state. Recent evidence indicates that some of these proteins may be regulated by redox agents. Reactive oxygen species (ROSs) and reactive nitrogen species (RNSs) have been historically considered pathological agents which can react with and damage many biological macromolecules including DNA, proteins, and lipids. However, a growing number of reports have suggested that the intracellular production of ROS is tightly regulated and that these redox agents serve as signaling molecules being involved in a variety of cell signaling pathways. Numerous observations have suggested that some Ras GTPases appear to regulate ROS production and that oxidants function as effector molecules for the small GTPases, thus contributing to their overall biological function. Thus, redox agents may act both as upstream regulators and as downstream effectors of Ras GTPases. Here we discuss current understanding concerning mechanisms and physiopathological implications of the interplay between GTPases and redox agents.
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Identification of protein nitrosothiols using phosphine-mediated selective reduction. Nitric Oxide 2011; 26:20-6. [PMID: 22100619 DOI: 10.1016/j.niox.2011.11.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2011] [Revised: 11/01/2011] [Accepted: 11/02/2011] [Indexed: 11/21/2022]
Abstract
Regulation of protein function by S-nitrosation of critical cysteines is known to be an important mechanism for nitric oxide signaling. Evidence for this comes from several different experimental approaches including the ascorbate-based biotin switch method. However technical problems with specificity and sensitivity of ascorbate reduction of S-nitrosothiols limit its usefulness and reliability. In the current study we report the use of triphenylphosphine ester derivatives to selectively reduce SNO bonds in proteins. After triphenylphosphine ester reduction, thiols were tagged with biotin or fluorescently labeled maleimide reagents. Importantly we demonstrate that these compounds are specific reductants of SNO in complex biological samples and do not reduce protein disulfides or protein thiols modified by hydrogen peroxide. Reduction proceeds efficiently in cell extracts and in whole fixed cells. Application of this approach allowed us to demonstrate S-nitrosation of specific cellular proteins, label S-nitrosoproteins in whole fixed cells (especially the nuclear compartment) and demonstrate S-nitrosoprotein formation in cells expressing inducible nitric oxide synthase.
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41
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Davis MF, Vigil D, Campbell SL. Regulation of Ras proteins by reactive nitrogen species. Free Radic Biol Med 2011; 51:565-75. [PMID: 21616138 PMCID: PMC3549334 DOI: 10.1016/j.freeradbiomed.2011.05.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 04/11/2011] [Accepted: 05/03/2011] [Indexed: 11/28/2022]
Abstract
Ras GTPases have been a subject of intense investigation since the early 1980s, when single point mutations in Ras were shown to cause deregulated cell growth control. Subsequently, Ras was identified as the most prevalent oncogene found in human cancer. Ras proteins regulate a host of pathways involved in cell growth, differentiation, and apoptosis by cycling between inactive GDP-bound and active GTP-bound states. Regulation of Ras activity is controlled by cellular factors that alter guanine nucleotide cycling. Oncogenic mutations prevent protein regulatory factors from down-regulating Ras activity, thereby maintaining Ras in a chronically activated state. The central dogma in the field is that protein modulatory factors are the primary regulators of Ras activity. Since the mid-1990s, however, evidence has accumulated that small molecule reactive nitrogen species (RNS) can also influence Ras guanine nucleotide cycling. Herein, we review the basic chemistry behind RNS formation and discuss the mechanism through which various RNS enhance nucleotide exchange in Ras proteins. In addition, we present studies that demonstrate the physiological relevance of RNS-mediated Ras activation within the context of immune system function, brain function, and cancer development. We also highlight future directions and experimental methods that may enhance our ability to detect RNS-mediated activation in cell cultures and in vivo. The development of such methods may ultimately pave new directions for detecting and elucidating how Ras proteins are regulated by redox species, as well as for targeting redox-activated Ras in cancer and other disease states.
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Affiliation(s)
- Michael F. Davis
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599
| | - Dom Vigil
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599
| | - Sharon L. Campbell
- Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599
- Department of Biochemistry and Biophysics, University of North Carolina, Chapel Hill, NC 27599
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Heo J, Wey M, Hong I. Insight into the 6-thiopurine-mediated termination of the invasive motility of tumor cells derived from inflammatory breast cancer. Biochemistry 2011; 50:5731-42. [PMID: 21568348 DOI: 10.1021/bi200347y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Our study showed that a combination of 6-thiopurine (6-TP) drugs and a redox agent effectively inhibits the motility of SUM cells derived from human inflammatory breast cancer (IBC) cells and RhoC-overexpressed mammary epithelium cells. This 6-TP-mediated inhibition of cell motility occurs because the treated 6-TPs target and inactivate RhoC. A molecular mechanism for inactivation by the 6-TP-mediated RhoC is proposed by which treated TPs are converted in cells into 6-thioguanosine phosphate (6-TGNP). This 6-TGNP in turn reacts with the Cys(20) side chain of the redox-sensitive GXXXCGK(S/T)C motif of RhoC to produce a 6-TGNP-RhoC disulfide adduct. A redox agent synergistically enhances the formation process of this disulfide. The adduct that is formed impedes RhoC guanine nucleotide exchange, which populates an inactive RhoC. Our results suggest that 6-TGNP can also react with the redox-sensitive GXXXCGK(S/T)C and GXXXXGK(S/T)C motif of RhoA and Rac, respectively, to produce a 6-TGNP-RhoA and 6-TGNP-Rac disulfide adduct. However, given that RhoC has been shown to be overexpressed in ∼90% of IBC lesions, the populated RhoC but not other Rho proteins is likely to be a primary target for 6-TPs and a redox agent to terminate the metastasis of IBC.
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Affiliation(s)
- Jongyun Heo
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019, USA.
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Heo J. Redox control of GTPases: from molecular mechanisms to functional significance in health and disease. Antioxid Redox Signal 2011; 14:689-724. [PMID: 20649471 DOI: 10.1089/ars.2009.2984] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Small GTPases, including the proto-oncoprotein Ras and Rho GTPases, are involved in various cellular signaling events. Some of these small GTPases are redox sensitive, including Ras, Rho, Ran, Dexras1, and Rhes GTPases. Thus, the redox-mediated regulation of these GTPases often determines the course of their cellular signaling cascades. This article takes into consideration the application of Marcus theory to potential redox-based molecular mechanisms in the regulation of these redox-sensitive GTPases and the relevance of such mechanisms to a specific redox-sensitive motif. The discussion also takes into account various diseases, including cancers, heart, and neuronal disorders, that are often linked with the dysregulation of the redox signaling cascades associated with these redox-sensitive GTPases.
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Affiliation(s)
- Jongyun Heo
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019, USA.
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Rosales-Corral S, Reiter RJ, Tan DX, Ortiz GG, Lopez-Armas G. Functional aspects of redox control during neuroinflammation. Antioxid Redox Signal 2010; 13:193-247. [PMID: 19951033 DOI: 10.1089/ars.2009.2629] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Neuroinflammation is a CNS reaction to injury in which some severe pathologies, regardless of their origin, converge. The phenomenon emphasizes crosstalk between neurons and glia and reveals a complex interaction with oxidizing agents through redox sensors localized in enzymes, receptors, and transcription factors. When oxidizing pressures cause reversible molecular changes, such as minimal or transitory proinflammatory cytokine overproduction, redox couples provide a means of translating the presence of reactive oxygen or nitrogen species into useful signals in the cell. Additionally, thiol-based redox sensors convey information about localized changes in redox potential induced by physiologic or pathologic situations. They are susceptible to oxidative changes and become key events during neuroinflammation, altering the course of a signaling response or the behavior of specific transcription factors. When oxidative stress augments the pressure on the intracellular environment, the effective reduction potential of redox pairs diminishes, and cell signaling shifts toward proinflammatory and proapoptotic signals, creating a vicious cycle between oxidative stress and neuroinflammation. In addition, electrophilic compounds derived from the oxidative cascade react with key protein thiols and interfere with redox signaling. This article reviews the relevant functional aspects of redox control during the neuroinflammatory process.
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Affiliation(s)
- Sergio Rosales-Corral
- Lab. Desarrollo-Envejecimiento, Enfermedades Neurodegenerativas, División de Neurociencias, Centro de Investigación Biomédica de Occidente (CIBO) del Instituto Mexicano del Seguro Social (IMSS) , Guadalajara, Jalisco. Mexico.
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45
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Wang R, Xu W, Zhang J, Li L. A new hexanuclear iron-selenium nitrosyl cluster: primary exploration of the preparation methods, structure, and spectroscopic and electrochemical properties. Inorg Chem 2010; 49:4814-9. [PMID: 20459063 DOI: 10.1021/ic9014509] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A new hexanuclear iron-selenium nitrosyl cluster, [(n-Bu)(4)N](2)[Fe(6)Se(6)(NO)(6)] (1), and a hexanuclear iron-sulfur nitrosyl cluster, [(n-Bu)(4)N](2)[Fe(6)S(6)(NO)(6)] (2), were synthesized by the solvent-thermal reactions of [(n-Bu)(4)N][Fe(CO)(3)NO] with selenium or sulfur in methanol, while a tetranuclear iron-sulfur nitrosyl cluster, (Me(4)N)[Fe(4)S(3)(NO)(7)] (3), was also prepared by the solvent-thermal reaction of FeCl(2).4H(2)O with thiourea in the presence of (CH(3))(4)NCl, NaNO(2), and methanol. Complexes 1-3 were characterized by IR, UV-vis, (1)H NMR, electrochemistry, and single-crystal X-ray diffraction analysis. IR spectra of complexes 1 and 2 show the characteristic NO stretching frequencies at 1694 and 1698 cm(-1), respectively, while the absorptions of complex 3 appear at 1799, 1744, and 1710 cm(-1). The UV-vis spectra of complexes 1-3 show different bands in the range of 259-562 nm, which are assigned to the transitions between orbitals delocalized over the Fe-S cluster, the ligand-to-metal charge transfer, pi*(NO)-d(Fe), and the metal-to-ligand charge transfer, d(Fe)-pi*(NO). Single-crystal X-ray structural analysis reveals that complex 1 crystallizes in the monoclinic P2(1)/n space group with two molecules per unit cell. Two parallel "chair-shaped" structures, consisting of three iron and three selenium atoms, are connected by Fe-Se bonds with an average distance of 2.341 A; each iron center is bonded to three selenium atoms and a nitrogen atom from the nitrosyl ligand with a pseudotetrahedral center geometry. Cyclic voltammograms of complexes 1 and 2 display two cathodic and three anodic current peaks with an unusually strong cathodic peak. Further electrochemical investigations demonstrated that the intensity of the unusually strong peak is a result of at least three processes. One is the quasi-reversible reduction, and the other two are from an irreversible electrochemical process, in which the compound goes through a typical electron transfer and chemical reaction mechanism. Compound 3 shows three quasi-reversible reductions.
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Affiliation(s)
- Rongming Wang
- Department of Chemistry and Biochemistry, California State University, Long Beach, 1250 Bellflower Boulevard, Long Beach, California 90840, USA.
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46
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Heo J, Hong I. Ras-Targeting Action of Thiopurines in the Presence of Reactive Nitrogen Species. Biochemistry 2010; 49:3965-76. [DOI: 10.1021/bi902090q] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Affiliation(s)
- Jongyun Heo
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019
| | - Inpyo Hong
- Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019
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47
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Aghajanian A, Wittchen ES, Campbell SL, Burridge K. Direct activation of RhoA by reactive oxygen species requires a redox-sensitive motif. PLoS One 2009; 4:e8045. [PMID: 19956681 PMCID: PMC2778012 DOI: 10.1371/journal.pone.0008045] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2009] [Accepted: 11/03/2009] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Rho family GTPases are critical regulators of the cytoskeleton and affect cell migration, cell-cell adhesion, and cell-matrix adhesion. As with all GTPases, their activity is determined by their guanine nucleotide-bound state. Understanding how Rho proteins are activated and inactivated has largely focused on regulatory proteins such as guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs). However, recent in vitro studies have indicated that GTPases may also be directly regulated by redox agents. We hypothesized that this redox-based mechanism occurs in cells and affects cytoskeletal dynamics, and in this report we conclude this is indeed a novel mechanism of regulating the GTPase RhoA. METHODOLOGY/PRINCIPAL FINDINGS In this report, we show that RhoA can be directly activated by reactive oxygen species (ROS) in cells, and that this requires two critical cysteine residues located in a unique redox-sensitive motif within the phosphoryl binding loop. First, we show that ROS can reversibly activate RhoA and induce stress fiber formation, a well characterized readout of RhoA activity. To determine the role of cysteine residues in this mechanism of regulation, we generated cysteine to alanine RhoA mutants. Mutation of these cysteines abolishes ROS-mediated activation and stress fiber formation, indicating that these residues are critical for redox-regulation of RhoA. Importantly, these mutants maintain the ability to be activated by GEFs. CONCLUSIONS/SIGNIFICANCE Our findings identify a novel mechanism for the regulation of RhoA in cells by ROS, which is independent of classical regulatory proteins. This mechanism of regulation may be particularly relevant in pathological conditions where ROS are generated and the cellular redox-balance altered, such as in asthma and ischemia-reperfusion injury.
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Affiliation(s)
- Amir Aghajanian
- Department of Cell and Developmental Biology, University of North Carolina at Chapel Hill, Lineberger Comprehensive Cancer Center, Chapel Hill, North Carolina, United States of America.
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48
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Leonard SE, Reddie KG, Carroll KS. Mining the thiol proteome for sulfenic acid modifications reveals new targets for oxidation in cells. ACS Chem Biol 2009; 4:783-99. [PMID: 19645509 DOI: 10.1021/cb900105q] [Citation(s) in RCA: 234] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Oxidation of cysteine to sulfenic acid has emerged as a biologically relevant post-translational modification with particular importance in redox-mediated signal transduction; however, the identity of modified proteins remains largely unknown. We recently reported DAz-1, a cell-permeable chemical probe capable of detecting sulfenic acid modified proteins directly in living cells. Here we describe DAz-2, an analogue of DAz-1 that exhibits significantly improved potency in vitro and in cells. Application of this new probe for global analysis of the sulfenome in a tumor cell line identifies most known sulfenic acid modified proteins: 14 in total, plus more than 175 new candidates, with further testing confirming oxidation in several candidates. The newly identified proteins have roles in signal transduction, DNA repair, metabolism, protein synthesis, redox homeostasis, nuclear transport, vesicle trafficking, and ER quality control. Cross-comparison of these results with those from disulfide, S-glutathionylation, and S-nitrosylation proteomes reveals moderate overlap, suggesting fundamental differences in the chemical and biological basis for target specificity. The combination of selective chemical enrichment and live-cell compatibility makes DAz-2 a powerful new tool with the potential to reveal new regulatory mechanisms in signaling pathways and identify new therapeutic targets.
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Affiliation(s)
| | | | - Kate S. Carroll
- Chemical Biology Graduate Program
- Life Sciences Institute
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109-2216
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49
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Wang R, Xu W, Zhang J, Li L. Synthesis, characterization and crystal structure of a dinuclear iron nitrosyl complex with 2-mercapto-1-[2-(4-pyridyl)-ethyl]-benzimidazolyl. J Mol Struct 2009; 923:110-113. [PMID: 20640187 DOI: 10.1016/j.molstruc.2009.02.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A new dinuclear iron nitrosyl complex [Fe(2)(C(14)H(12)N(3)S)(2)(NO)(4)] (1) (C(14)H(12)N(3)S = 2-mercapto-1-[2-(4-pyridyl)-ethyl]-benzimidazolyl) has been obtained by the reaction of Fe(NO)(2)(CO)(2) with 2-mercapto-1-[2-(4-pyridyl)-ethyl]-benzimidazole in CH(3)OH under moderate condition. Complex 1 was characterized by IR, UV-vis, electrochemistry and single crystal X-ray diffraction. IR spectrum displays two strong characteristic NO stretching frequencies (nu(NO)) in solution and in solid state. Cyclic voltammetry shows one irreversible, two quasi-reversible and two reversible one-electron reductions and irreversible oxidizations. This result is consistent with the fact that complex 1 is very unstable and ready to lose NO in the air. As showing in the single crystal X-ray diffraction, complex 1 forms a "chair-shape" structure by the connections of two iron centers and S-C-N frames of benzimidazole. The dihedral angle of benzimidazole ring and 2Fe-2S plane is 73.6 degrees . The crystal data are the following: 1, monoclinic, space group P2(1)/c, a = 10.43940(10) A, b = 16.0900(2) A, c = 10.13240(10) A, alpha = 90 degrees , beta = 111.0940(10) degrees , gamma = 90 degrees , V = 1587.89(3) A(3), Z = 4.
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Affiliation(s)
- Rongming Wang
- Department of Chemistry and Biochemistry, California State University, Long Beach, 1250 Bellflower Blvd., Long Beach, CA, 90840, USA
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50
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Wang R, Camacho-Fernandez MA, Xu W, Zhang J, Li L. Neutral and reduced Roussin's red salt ester [Fe(2)(mu-RS)(2)(NO)(4)] (R = n-Pr, t-Bu, 6-methyl-2-pyridyl and 4,6-dimethyl-2-pyrimidyl): synthesis, X-ray crystal structures, spectroscopic, electrochemical and density functional theoretical investigations. Dalton Trans 2008:777-86. [PMID: 19156270 DOI: 10.1039/b810230a] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of Roussin's red salt esters [Fe(2)(micro-RS)(2)(NO)(4)] (R = n-Pr (), t-Bu (), 6-methyl-2-pyridyl () and 4,6-dimethyl-2-pyrimidyl ()) were synthesized by the reaction of Fe(NO)(2)(CO)(2) with thiols or thiolates. Complexes were characterized by IR, UV-vis, (1)H-NMR, electrochemistry, and single-crystal X-ray diffraction analysis. The IR spectra of complexes display one weak and two strong NO stretching frequencies (nu(NO)) in solution, but only two strong nu(NO) in the solid. Density functional theoretical (DFT) calculations using complex as model suggest that two spatial isomers of these complexes bear a 3 kcal energy difference in solution. Frequency calculations of the two isomers provide insight on the origin of the vibrational bands and explain the IR observation of complexes in the solid state and in solution. Cyclic voltammetry shows two quasi-reversible, one-electron reductions for complexes and one quasi-reversible, one-electron reduction for complexes . The paramagnetic complexes [Fe(2)(micro-RS)(2)(NO)(4)](-) ((-)-(-)), which are prepared by the chemical reduction of neutral complexes [Fe(2)(micro-RS)(2)(NO)(4)] (), have also been investigated by EPR spectroscopy. Interestingly, the EPR spectra of complexes [Fe(2)(micro-RS)(2)(NO)(4)](-) ((-)-(-)) exhibit an isotropic signal of g = 1.998-2.004 without hyperfine splitting in the temperature range 180-298 K. The observations are consistent with the results of the calculations, which reveal that the unpaired electron is dominantly delocalized over the two sulfur and two iron atoms. The difference of the g values between the reduced form of Roussin's red ester and the typical dinitrosyl iron complexes is explained, for the first time, by the difference in unpaired electron distributions between the two types of complexes, which provides the theoretical bases for the use of g values as a spectroscopic tool to differentiate these biologically active complexes.
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Affiliation(s)
- Rongming Wang
- Department of Chemistry and Biochemistry, California State University, Long Beach 1250 Bellflower Blvd., Long Beach, CA90840, USA
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