1
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Koussis K, Haase S, Withers-Martinez C, Flynn HR, Kunzelmann S, Christodoulou E, Ibrahim F, Skehel M, Baker DA, Blackman MJ. Activation loop phosphorylation and cGMP saturation of PKG regulate egress of malaria parasites. PLoS Pathog 2024; 20:e1012360. [PMID: 38935780 PMCID: PMC11236177 DOI: 10.1371/journal.ppat.1012360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 07/10/2024] [Accepted: 06/20/2024] [Indexed: 06/29/2024] Open
Abstract
The cGMP-dependent protein kinase (PKG) is the sole cGMP sensor in malaria parasites, acting as an essential signalling hub to govern key developmental processes throughout the parasite life cycle. Despite the importance of PKG in the clinically relevant asexual blood stages, many aspects of malarial PKG regulation, including the importance of phosphorylation, remain poorly understood. Here we use genetic and biochemical approaches to show that reduced cGMP binding to cyclic nucleotide binding domain B does not affect in vitro kinase activity but prevents parasite egress. Similarly, we show that phosphorylation of a key threonine residue (T695) in the activation loop is dispensable for kinase activity in vitro but is essential for in vivo PKG function, with loss of T695 phosphorylation leading to aberrant phosphorylation events across the parasite proteome and changes to the substrate specificity of PKG. Our findings indicate that Plasmodium PKG is uniquely regulated to transduce signals crucial for malaria parasite development.
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Affiliation(s)
- Konstantinos Koussis
- Malaria Biochemistry Laboratory, Francis Crick Institute, London, United Kingdom
| | - Silvia Haase
- Host-Pathogen Interactions in Cryptosporidiosis Laboratory, The Francis Crick Institute, London, United Kingdom
| | | | - Helen R. Flynn
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Simone Kunzelmann
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Evangelos Christodoulou
- Structural Biology Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Fairouz Ibrahim
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - Mark Skehel
- Proteomics Science Technology Platform, The Francis Crick Institute, London, United Kingdom
| | - David A. Baker
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
| | - Michael J. Blackman
- Malaria Biochemistry Laboratory, Francis Crick Institute, London, United Kingdom
- Faculty of Infectious and Tropical Diseases, London School of Hygiene & Tropical Medicine, London, United Kingdom
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2
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Madan LK, Welsh CL, Kornev AP, Taylor SS. The "violin model": Looking at community networks for dynamic allostery. J Chem Phys 2023; 158:081001. [PMID: 36859094 PMCID: PMC9957607 DOI: 10.1063/5.0138175] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/03/2023] [Indexed: 02/09/2023] Open
Abstract
Allosteric regulation of proteins continues to be an engaging research topic for the scientific community. Models describing allosteric communication have evolved from focusing on conformation-based descriptors of protein structural changes to appreciating the role of internal protein dynamics as a mediator of allostery. Here, we explain a "violin model" for allostery as a contemporary method for approaching the Cooper-Dryden model based on redistribution of protein thermal fluctuations. Based on graph theory, the violin model makes use of community network analysis to functionally cluster correlated protein motions obtained from molecular dynamics simulations. This Review provides the theory and workflow of the methodology and explains the application of violin model to unravel the workings of protein kinase A.
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Affiliation(s)
- Lalima K. Madan
- Author to whom correspondence should be addressed: and . Telephone: 843.792.4525. Fax: 843.792.0481
| | - Colin L. Welsh
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, 173 Ashley Ave., Charleston, South Carolina 29425, USA
| | - Alexandr P. Kornev
- Department of Pharmacology, University of California San Diego, 9500 Gilman Drive, San Diego, California, 92093, USA
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3
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Yayen J, Chan C, Sun CM, Chiang SF, Chiou TJ. Conservation of land plant-specific receptor-like cytoplasmic kinase subfamily XI possessing a unique kinase insert domain. FRONTIERS IN PLANT SCIENCE 2023; 14:1117059. [PMID: 36909417 PMCID: PMC9992409 DOI: 10.3389/fpls.2023.1117059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 01/30/2023] [Indexed: 06/18/2023]
Abstract
The number of genes encoding receptor-like kinases (RLKs) has expanded in the plant lineage. Their expansion has resulted in the emergence of diverse domain architectures that function in signaling cascades related to growth, development, and stress response. In this study, we focused on receptor-like cytoplasmic kinase subfamily XI (RLCK XI) in plants. We discovered an exceptionally long kinase insert domain (KID), averaging 280 amino acids, between subdomains VII and VIII of the conserved protein kinase domain. Using sequence homology search, we identified members of RLCK XI with the unique KID architecture in terrestrial plants, up to a single copy in several hornwort and liverwort species. The KID shows a high propensity for being disordered, resembling the activation segment in the model kinase domain. Several conserved sequence motifs were annotated along the length of the KID. Of note, the KID harbors repetitive nuclear localization signals capable of mediating RLCK XI translocation from the plasma membrane to the nucleus. The possible physiological implication of dual localization of RLCK XI members is discussed. The presence of a KID in RLCK XI represents a unique domain architecture among RLKs specific to land plants.
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Affiliation(s)
- Joseph Yayen
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica and National Chung Hsing University, Taipei, Taiwan
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, Taiwan
| | - Ching Chan
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Ching-Mei Sun
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Su-Fen Chiang
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
| | - Tzyy-Jen Chiou
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica and National Chung Hsing University, Taipei, Taiwan
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
- Biotechnology Center, National Chung Hsing University, Taichung, Taiwan
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4
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Palhano Zanela TM, Woudenberg A, Romero Bello KG, Underbakke ES. Activation loop phosphorylation tunes conformational dynamics underlying Pyk2 tyrosine kinase activation. Structure 2023; 31:447-454.e5. [PMID: 36870334 DOI: 10.1016/j.str.2023.02.003] [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: 12/04/2022] [Revised: 01/11/2023] [Accepted: 02/07/2023] [Indexed: 03/06/2023]
Abstract
Pyk2 is a multidomain non-receptor tyrosine kinase that undergoes a multistage activation mechanism. Activation is instigated by conformational rearrangements relieving autoinhibitory FERM domain interactions. The kinase autophosphorylates a central linker residue to recruit Src kinase. Pyk2 and Src mutually phosphorylate activation loops to confer full activation. While the mechanisms of autoinhibition are established, the conformational dynamics associated with autophosphorylation and Src recruitment remain unclear. We employ hydrogen/deuterium exchange mass spectrometry and kinase activity profiling to map the conformational dynamics associated with substrate binding and Src-mediated activation loop phosphorylation. Nucleotide engagement stabilizes the autoinhibitory interface, while phosphorylation deprotects both FERM and kinase regulatory surfaces. Phosphorylation organizes active site motifs linking catalytic loop with activation segment. Dynamics of the activation segment anchor propagate to EF/G helices to prevent reversion of the autoinhibitory FERM interaction. We employ targeted mutagenesis to dissect how phosphorylation-induced conformational rearrangements elevate kinase activity above the basal autophosphorylation rate.
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Affiliation(s)
- Tania M Palhano Zanela
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Alexzandrea Woudenberg
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Karen G Romero Bello
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Eric S Underbakke
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
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5
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Wang Y, Zou W, Niu Y, Wang S, Chen B, Xiong R, Zhang P, Luo Z, Wu Y, Fan C, Zhong Z, Xu P, Peng Y. Phosphorylation of enteroviral 2A pro at Ser/Thr125 benefits its proteolytic activity and viral pathogenesis. J Med Virol 2023; 95:e28400. [PMID: 36511115 PMCID: PMC10107306 DOI: 10.1002/jmv.28400] [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: 09/18/2022] [Revised: 11/19/2022] [Accepted: 12/09/2022] [Indexed: 12/15/2022]
Abstract
Enteroviral 2A proteinase (2Apro ), a well-established and important viral functional protein, plays a key role in shutting down cellular cap-dependent translation, mainly via its proteolytic activity, and creating optimal conditions for Enterovirus survival. Accumulated data show that viruses take advantage of various signaling cascades for their life cycle; studies performed by us and others have demonstrated that the extracellular signal-regulated kinase (ERK) pathway is essential for enterovirus A71 (EV-A71) and other viruses replication. We recently showed that ERK1/2 is required for the proteolytic activity of viral 2Apro ; however, the mechanism underlying the regulation of 2Apro remains unknown. Here, we demonstrated that the 125th residue Ser125 of EV-A71 2Apro or Thr125 of coxsackievirus B3 2Apro , which is highly conserved in the Enterovirus, was phosphorylated by ERK1/2. Importantly, 2Apro with phosphor-Ser/Thr125 had much stronger proteolytic activity toward eukaryotic initiation factor 4GI and rendered the virus more efficient for multiplication and pathogenesis in hSCARB2 knock-in mice than that in nonphospho-Ser/Thr125A (S/T125A) mutants. Notably, phosphorylation-mimic mutations caused deleterious changes in 2Apro catalytic function (S/T125D/E) and in viral propagation (S125D). Crystal structure simulation analysis showed that Ser125 phosphorylation in EV-A71 2Apro enabled catalytic Cys to adopt an optimal conformation in the catalytic triad His-Asp-Cys, which enhances 2Apro proteolysis. Therefore, we are the first to report Ser/Thr125 phosphorylation of 2Apro increases enteroviral adaptation to the host to ensure enteroviral multiplication, causing pathogenicity. Additionally, weakened viruses containing a S/T125A mutation could be a general strategy to develop attenuated Enterovirus vaccines.
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Affiliation(s)
- Yuya Wang
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Wenjia Zou
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Yan Niu
- Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, China
| | - Sanyuan Wang
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Bangtao Chen
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Rui Xiong
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Peng Zhang
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Zhijun Luo
- Jiangxi Provincial Key Laboratory of Tumor Pathogens and Molecular Pathology, Queen Mary School, Nanchang University Jiangxi Medical College, Nanchang, China
| | - Yong Wu
- Division of Animal Model Research, Institute for Laboratory Animal Resources, National Institutes for Food and Drug Control, Beijing, China
| | - Changfa Fan
- Division of Animal Model Research, Institute for Laboratory Animal Resources, National Institutes for Food and Drug Control, Beijing, China
| | - Zhaohua Zhong
- Department of Microbiology, Harbin Medical University, Harbin, China
| | - Ping Xu
- Department of Medicinal Chemistry, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing, China
| | - Yihong Peng
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
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6
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Interaction of TOR and PKA Signaling in S. cerevisiae. Biomolecules 2022; 12:biom12020210. [PMID: 35204711 PMCID: PMC8961621 DOI: 10.3390/biom12020210] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/22/2022] [Accepted: 01/25/2022] [Indexed: 01/13/2023] Open
Abstract
TOR and PKA signaling are the major growth-regulatory nutrient-sensing pathways in S. cerevisiae. A number of experimental findings demonstrated a close relationship between these pathways: Both are responsive to glucose availability. Both regulate ribosome production on the transcriptional level and repress autophagy and the cellular stress response. Sch9, a major downstream effector of TORC1 presumably shares its kinase consensus motif with PKA, and genetic rescue and synthetic defects between PKA and Sch9 have been known for a long time. Further, studies in the first decade of this century have suggested direct regulation of PKA by TORC1. Nonetheless, the contribution of a potential direct cross-talk vs. potential sharing of targets between the pathways has still not been completely resolved. What is more, other findings have in contrast highlighted an antagonistic relationship between the two pathways. In this review, I explore the association between TOR and PKA signaling, mainly by focusing on proteins that are commonly referred to as shared TOR and PKA targets. Most of these proteins are transcription factors which to a large part explain the major transcriptional responses elicited by TOR and PKA upon nutrient shifts. I examine the evidence that these proteins are indeed direct targets of both pathways and which aspects of their regulation are targeted by TOR and PKA. I further explore if they are phosphorylated on shared sites by PKA and Sch9 or when experimental findings point towards regulation via the PP2ASit4/PP2A branch downstream of TORC1. Finally, I critically review data suggesting direct cross-talk between the pathways and its potential mechanism.
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7
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Chen H, Shen Y, Liang Y, Qiu Y, Xu M, Li C. Selexipag improves Lipopolysaccharide-induced ARDS on C57BL/6 mice by modulating the cAMP/PKA and cAMP/Epac1 signaling pathways. Biol Pharm Bull 2022; 45:1043-1052. [DOI: 10.1248/bpb.b21-01057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Hongliu Chen
- Department of Emergency, the First Affiliated Hospital of Guangxi Medical University
| | - Ying Shen
- General Practice School, Guangxi Medical University
| | - Yi Liang
- Department of Respiratory Medicine, the First Affiliated Hospital of Guangxi Medical University
| | - Ying Qiu
- Department of Emergency, the First Affiliated Hospital of Guangxi Medical University
| | - Meili Xu
- Department of Emergency, the First Affiliated Hospital of Guangxi Medical University
| | - Chaoqian Li
- Department of Emergency, the First Affiliated Hospital of Guangxi Medical University
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8
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Hitz E, Wiedemar N, Passecker A, Graça BAS, Scheurer C, Wittlin S, Brancucci NMB, Vakonakis I, Mäser P, Voss TS. The 3-phosphoinositide-dependent protein kinase 1 is an essential upstream activator of protein kinase A in malaria parasites. PLoS Biol 2021; 19:e3001483. [PMID: 34879056 PMCID: PMC8687544 DOI: 10.1371/journal.pbio.3001483] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 12/20/2021] [Accepted: 11/12/2021] [Indexed: 01/11/2023] Open
Abstract
Cyclic adenosine monophosphate (cAMP)-dependent protein kinase A (PKA) signalling is essential for the proliferation of Plasmodium falciparum malaria blood stage parasites. The mechanisms regulating the activity of the catalytic subunit PfPKAc, however, are only partially understood, and PfPKAc function has not been investigated in gametocytes, the sexual blood stage forms that are essential for malaria transmission. By studying a conditional PfPKAc knockdown (cKD) mutant, we confirm the essential role for PfPKAc in erythrocyte invasion by merozoites and show that PfPKAc is involved in regulating gametocyte deformability. We furthermore demonstrate that overexpression of PfPKAc is lethal and kills parasites at the early phase of schizogony. Strikingly, whole genome sequencing (WGS) of parasite mutants selected to tolerate increased PfPKAc expression levels identified missense mutations exclusively in the gene encoding the parasite orthologue of 3-phosphoinositide-dependent protein kinase-1 (PfPDK1). Using targeted mutagenesis, we demonstrate that PfPDK1 is required to activate PfPKAc and that T189 in the PfPKAc activation loop is the crucial target residue in this process. In summary, our results corroborate the importance of tight regulation of PfPKA signalling for parasite survival and imply that PfPDK1 acts as a crucial upstream regulator in this pathway and potential new drug target.
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Affiliation(s)
- Eva Hitz
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Natalie Wiedemar
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Armin Passecker
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Beatriz A. S. Graça
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Christian Scheurer
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Sergio Wittlin
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Nicolas M. B. Brancucci
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Ioannis Vakonakis
- Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Pascal Mäser
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | - Till S. Voss
- Department of Medical Parasitology and Infection Biology, Swiss Tropical and Public Health Institute, Basel, Switzerland
- University of Basel, Basel, Switzerland
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9
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Activation loop phosphorylaton of a non-RD receptor kinase initiates plant innate immune signaling. Proc Natl Acad Sci U S A 2021; 118:2108242118. [PMID: 34531323 PMCID: PMC8463890 DOI: 10.1073/pnas.2108242118] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/04/2021] [Indexed: 01/01/2023] Open
Abstract
Receptor kinases (RKs) are fundamental for extracellular sensing and regulate development and stress responses across kingdoms. In plants, leucine-rich repeat receptor kinases (LRR-RKs) are primarily peptide receptors that regulate responses to myriad internal and external stimuli. Phosphorylation of LRR-RK cytoplasmic domains is among the earliest responses following ligand perception, and reciprocal transphosphorylation between a receptor and its coreceptor is thought to activate the receptor complex. Originally proposed based on characterization of the brassinosteroid receptor, the prevalence of complex activation via reciprocal transphosphorylation across the plant RK family has not been tested. Using the LRR-RK ELONGATION FACTOR TU RECEPTOR (EFR) as a model, we set out to understand the steps critical for activating RK complexes. While the EFR cytoplasmic domain is an active protein kinase in vitro and is phosphorylated in a ligand-dependent manner in vivo, catalytically deficient EFR variants are functional in antibacterial immunity. These results reveal a noncatalytic role for EFR in triggering immune signaling and indicate that reciprocal transphoshorylation is not a ubiquitous requirement for LRR-RK complex activation. Rather, our analysis of EFR along with a detailed survey of the literature suggests a distinction between LRR-RKs with RD- versus non-RD protein kinase domains. Based on newly identified phosphorylation sites that regulate the activation state of the EFR complex in vivo, we propose that LRR-RK complexes containing a non-RD protein kinase may be regulated by phosphorylation-dependent conformational changes of the ligand-binding receptor, which could initiate signaling either allosterically or through driving the dissociation of negative regulators of the complex.
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10
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Bayazeid O, Rahman T. Correlation Analysis of Target Selectivity and Side Effects of FDA‐Approved Kinase Inhibitors**. ChemistrySelect 2021. [DOI: 10.1002/slct.202101367] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Omer Bayazeid
- Department of Pharmacognosy Faculty of Pharmacy Hacettepe University, Sihhiye 06100 Ankara Turkey
| | - Taufiq Rahman
- Department of Pharmacology University of Cambridge Tennis Court Road Cambridge CB2 1PD UK
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11
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Baro Graf C, Ritagliati C, Stival C, Luque GM, Gentile I, Buffone MG, Krapf D. Everything you ever wanted to know about PKA regulation and its involvement in mammalian sperm capacitation. Mol Cell Endocrinol 2020; 518:110992. [PMID: 32853743 DOI: 10.1016/j.mce.2020.110992] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 08/11/2020] [Accepted: 08/12/2020] [Indexed: 12/29/2022]
Abstract
The 3', 5'-cyclic adenosine monophosphate (cAMP) dependent protein kinase (PKA) is a tetrameric holoenzyme comprising a set of two regulatory subunits (PKA-R) and two catalytic (PKA-C) subunits. The PKA-R subunits act as sensors of cAMP and allow PKA-C activity. One of the first signaling events observed during mammalian sperm capacitation is PKA activation. Thus, understanding how PKA activity is restricted in space and time is crucial to decipher the critical steps of sperm capacitation. It is widely accepted that PKA specificity depends on several levels of regulation. Anchoring proteins play a pivotal role in achieving proper localization signaling, subcellular targeting and cAMP microdomains. These multi-factorial regulation steps are necessary for a precise spatio-temporal activation of PKA. Here we discuss recent understanding of regulatory mechanisms of PKA in mammalian sperm, such as post-translational modifications, in the context of its role as the master orchestrator of molecular events conducive to capacitation.
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Affiliation(s)
- Carolina Baro Graf
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina; Laboratorio de Medicina Reproductiva (LMR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Carla Ritagliati
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina
| | - Cintia Stival
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina
| | - Guillermina M Luque
- Laboratory of Cellular and Molecular Reproductive Biology, Instituto de Biología y Medicina Experimental (IBYME), CONICET, Buenos Aires, Argentina
| | - Iñaki Gentile
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina
| | - Mariano G Buffone
- Laboratory of Cellular and Molecular Reproductive Biology, Instituto de Biología y Medicina Experimental (IBYME), CONICET, Buenos Aires, Argentina
| | - Dario Krapf
- Laboratory of Cell Signal Transduction Networks, Instituto de Biología Molecular y Celular de Rosario (IBR), CONICET-UNR, Rosario, Argentina; Laboratorio de Medicina Reproductiva (LMR), Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Rosario, Argentina.
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12
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Fujino Y, Miyagawa T, Torii M, Inoue M, Fujii Y, Okanishi H, Kanai Y, Masui R. Structural changes induced by ligand binding drastically increase the thermostability of the Ser/Thr protein kinase TpkD from Thermus thermophilus HB8. FEBS Lett 2020; 595:264-274. [PMID: 33159808 DOI: 10.1002/1873-3468.13996] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/26/2020] [Accepted: 11/02/2020] [Indexed: 11/06/2022]
Abstract
Thermophilic proteins maintain their structure at high temperatures through a combination of various factors. Here, we report the ligand-induced stabilization of a thermophilic Ser/Thr protein kinase. Thermus thermophilus TpkD unfolds completely at 55 °C despite the optimum growth temperature of 75 °C. Unexpectedly, we found that the TpkD structure is drastically stabilized by its natural ligands ATP and ADP, as evidenced by the increase in the melting temperature to 80 °C. Such a striking effect of a substrate on thermostability has not been reported for other protein kinases. Conformational changes upon ATP binding were observed in fluorescence quenching and limited proteolysis experiments. Urea denaturation of Trp mutants suggested that ATP binding affects not only the ATP-binding site, but also the remote regions. Our findings shed light on thermoadaptation of thermophilic proteins.
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Affiliation(s)
- Yusuke Fujino
- Graduate School of Science, Osaka City University, Japan
| | - Takero Miyagawa
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
| | - Masayuki Torii
- Graduate School of Science, Osaka City University, Japan
| | - Masao Inoue
- Graduate School of Agriculture, Kyoto University, Japan
| | - Yuki Fujii
- Graduate School of Science, Osaka City University, Japan
| | | | - Yoshikatsu Kanai
- Graduate School of Medicine, Osaka University, Suita, Japan.,Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiative, Osaka University, Suita, Japan
| | - Ryoji Masui
- Graduate School of Science, Osaka City University, Japan
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13
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Setny P. Conserved internal hydration motifs in protein kinases. Proteins 2020; 88:1578-1591. [DOI: 10.1002/prot.25977] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 05/18/2020] [Accepted: 07/05/2020] [Indexed: 01/14/2023]
Affiliation(s)
- Piotr Setny
- Centre of New Technologies University of Warsaw Warsaw Poland
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14
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Chan TO, Armen RS, Yadav S, Shah S, Zhang J, Tiegs BC, Keny N, Blumhof B, Deshpande DA, Rodeck U, Penn RB. A tripartite cooperative mechanism confers resistance of the protein kinase A catalytic subunit to dephosphorylation. J Biol Chem 2020; 295:3316-3329. [PMID: 31964716 DOI: 10.1074/jbc.ra119.010004] [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: 06/29/2019] [Revised: 12/28/2019] [Indexed: 11/06/2022] Open
Abstract
Phosphorylation of specific residues in the activation loops of AGC kinase group (protein kinase A, G, and C families) is required for activity of most of these kinases, including the catalytic subunit of PKA (PKAc). Although many phosphorylated AGC kinases are sensitive to phosphatase-mediated dephosphorylation, the PKAc activation loop uniquely resists dephosphorylation, rendering it "constitutively" phosphorylated in cells. Previous biophysical experiments and structural modeling have suggested that the N-terminal myristoylation signal and the C-terminal FXXF motif in PKAc regulate its thermal stability and catalysis. Here, using site-directed mutagenesis, molecular modeling, and in cell-free and cell-based systems, we demonstrate that substitutions of either the PKAc myristoylation signal or the FXXF motif only modestly reduce phosphorylation and fail to affect PKAc function in cells. However, we observed that these two sites cooperate with an N-terminal FXXW motif to cooperatively establish phosphatase resistance of PKAc while not affecting kinase-dependent phosphorylation of the activation loop. We noted that this tripartite cooperative mechanism of phosphatase resistance is functionally relevant, as demonstrated by changes in morphology, adhesion, and migration of human airway smooth muscle cells transfected with PKAc variants containing amino acid substitutions in these three sites. These findings establish that three allosteric sites located at the PKAc N and C termini coordinately regulate the phosphatase sensitivity of this enzyme. This cooperative mechanism of phosphatase resistance of AGC kinase opens new perspectives toward therapeutic manipulation of kinase signaling in disease.
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Affiliation(s)
- Tung O Chan
- Center for Translational Medicine and Korman Respiratory Institute, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107; Sydney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107.
| | - Roger S Armen
- Department of Pharmaceutical Sciences, College of Pharmacy, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Santosh Yadav
- Center for Translational Medicine and Korman Respiratory Institute, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Sushrut Shah
- Center for Translational Medicine and Korman Respiratory Institute, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Jin Zhang
- Center for Translational Medicine and Korman Respiratory Institute, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Brian C Tiegs
- Center for Translational Medicine and Korman Respiratory Institute, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Nikhil Keny
- Center for Translational Medicine and Korman Respiratory Institute, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Brian Blumhof
- Center for Translational Medicine and Korman Respiratory Institute, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Deepak A Deshpande
- Center for Translational Medicine and Korman Respiratory Institute, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Ulrich Rodeck
- Sydney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, Pennsylvania 19107; Department of Dermatology and Cutaneous Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
| | - Raymond B Penn
- Center for Translational Medicine and Korman Respiratory Institute, Department of Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107
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15
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Activation of RSK by phosphomimetic substitution in the activation loop is prevented by structural constraints. Sci Rep 2020; 10:591. [PMID: 31953410 PMCID: PMC6969211 DOI: 10.1038/s41598-019-56937-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 12/19/2019] [Indexed: 11/08/2022] Open
Abstract
The activation of the majority of AGC kinases is regulated by two phosphorylation events on two conserved serine/threonine residues located on the activation loop and on the hydrophobic motif, respectively. In AGC kinase family, phosphomimetic substitutions with aspartate or glutamate, leading to constitutive activation, have frequently occurred at the hydrophobic motif site. On the contrary, phosphomimetic substitutions in the activation loop are absent across the evolution of AGC kinases. This observation is explained by the failure of aspartate and glutamate to mimic phosphorylatable serine/threonine in this regulatory site. By detailed 3D structural simulations of RSK2 and further biochemical evaluation in cells, we show that the phosphomimetic residue on the activation loop fails to form a critical salt bridge with R114, necessary to reorient the αC-helix and to activate the protein. By a phylogenetic analysis, we point at a possible coevolution of a phosphorylatable activation loop and the presence of a conserved positively charged amino acid on the αC-helix. In sum, our analysis leads to the unfeasibility of phosphomimetic substitution in the activation loop of RSK and, at the same time, highlights the peculiar structural role of activation loop phosphorylation.
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16
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Wu Z, Jin Y, Chen B, Gugger MK, Wilkinson-Johnson CL, Tiambeng TN, Jin S, Ge Y. Comprehensive Characterization of the Recombinant Catalytic Subunit of cAMP-Dependent Protein Kinase by Top-Down Mass Spectrometry. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2019; 30:2561-2570. [PMID: 31792770 PMCID: PMC6922056 DOI: 10.1007/s13361-019-02341-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/04/2019] [Accepted: 09/09/2019] [Indexed: 05/22/2023]
Abstract
Reversible phosphorylation plays critical roles in cell growth, division, and signal transduction. Kinases which catalyze the transfer of γ-phosphate groups of nucleotide triphosphates to their substrates are central to the regulation of protein phosphorylation and are therefore important therapeutic targets. Top-down mass spectrometry (MS) presents unique opportunities to study protein kinases owing to its capabilities in comprehensive characterization of proteoforms that arise from alternative splicing, sequence variations, and post-translational modifications. Here, for the first time, we developed a top-down MS method to characterize the catalytic subunit (C-subunit) of an important kinase, cAMP-dependent protein kinase (PKA). The recombinant PKA C-subunit was expressed in Escherichia coli and successfully purified via his-tag affinity purification. By intact mass analysis with high resolution and high accuracy, four different proteoforms of the affinity-purified PKA C-subunit were detected, and the most abundant proteoform was found containing seven phosphorylations with the removal of N-terminal methionine. Subsequently, the seven phosphorylation sites of the most abundant PKA C-subunit proteoform were characterized simultaneously using tandem MS methods. Four sites were unambiguously identified as Ser10, Ser11, Ser18, and Ser30, and the remaining phosphorylation sites were localized to Ser2/Ser3, Ser358/Thr368, and Thr[215-224]Tyr in the PKA C-subunit sequence with a 20mer 6xHis-tag added at the N-terminus. Interestingly, four of these seven phosphorylation sites were located at the 6xHis-tag. Furthermore, we have performed dephosphorylation reaction by Lambda protein phosphatase and showed that all phosphorylations of the recombinant PKA C-subunit phosphoproteoforms were removed by this phosphatase.
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Affiliation(s)
- Zhijie Wu
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Yutong Jin
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Bifan Chen
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Morgan K Gugger
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | | | - Timothy N Tiambeng
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Song Jin
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Ying Ge
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI, 53706, USA.
- Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI, 53705, USA.
- Human Proteomics Program, University of Wisconsin-Madison, Madison, WI, 53705, USA.
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17
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Bansal N, Sciabola S, Bhisetti G. Understanding allosteric interactions in hMLKL protein that modulate necroptosis and its inhibition. Sci Rep 2019; 9:16853. [PMID: 31727943 PMCID: PMC6856060 DOI: 10.1038/s41598-019-53078-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Accepted: 10/25/2019] [Indexed: 12/20/2022] Open
Abstract
Mixed Lineage Kinase domain-Like (MLKL), a key player in necroptosis, is a multi-domain protein with an N-terminal 4 helical bundle (4HB) and a pseudokinase domain (PsK) connected by brace helices. Phosphorylation of PsK domain of MLKL is a key step towards oligomerization of 4HB domain that causes cell death. Necrosulfonamide (NSA) binds to the 4HB domain of MLKL to inhibit necroptosis. To understand the molecular details of MLKL function and it's inhibition, we have performed a molecular dynamic study on hMLKL protein in apo, phosphorylated and NSA-bound states for a total 3 μs simulation time. Our simulations show increased inter-domain flexibility, increased rigidification of the activation loop and increased alpha helical content in the brace helix region revealing a form of monomeric hMLKL necessary for oligomerization upon phosphorylation as compared to apo state. NSA binding disrupts this activated form and causes two main effects on hMLKL conformation: (1) locking of the relative orientation of 4HB and PsK domains by the formation of several new interactions and (2) prevention of key 4HB residues to participate in cross-linking for oligomer formation. This new understanding of the effect of hMLKL conformations on phosphorylation and NSA binding suggest new avenues for designing effective allosteric inhibitors of hMLKL.
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Affiliation(s)
- Nupur Bansal
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA, 02142, United States of America
| | - Simone Sciabola
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA, 02142, United States of America
| | - Govinda Bhisetti
- Biotherapeutic and Medicinal Sciences, Biogen, 225 Binney Street, Cambridge, MA, 02142, United States of America.
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18
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Tsai CC, Yue Z, Shen J. How Electrostatic Coupling Enables Conformational Plasticity in a Tyrosine Kinase. J Am Chem Soc 2019; 141:15092-15101. [PMID: 31476863 DOI: 10.1021/jacs.9b06064] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Protein kinases are important cellular signaling molecules involved in cancer and a multitude of other diseases. It is well-known that inactive kinases display a remarkable conformational plasticity; however, the molecular mechanisms remain poorly understood. Conformational heterogeneity presents an opportunity but also a challenge in kinase drug discovery. The ability to predictively model various conformational states could accelerate selective inhibitor design. Here we performed a proton-coupled molecular dynamics study to explore the conformational landscape of a c-Src kinase. Starting from a completely inactive structure, the simulations captured all major types of conformational states without the use of a target structure, mutation, or bias. The simulations allowed us to test the experimental hypotheses regarding the mechanism of DFG flip, its coupling to the αC-helix movement, and the formation of regulatory spine. Perhaps the most significant finding is how key titratable residues, such as DFG-Asp, αC-Glu, and HRD-Asp, change protonation states dependent on the DFG, αC, and activation loop conformations. Our data offer direct evidence to support a long-standing hypothesis that protonation of Asp favors the DFG-out state and explain why DFG flip is also possible in simulations with deprotonated Asp. The simulations also revealed intermediate states, among which a unique DFG-out/α-C state formed as DFG-Asp is moved into a back pocket forming a salt bridge with catalytic Lys, which can be tested in selective inhibitor design. Our finding of how proton coupling enables the remarkable conformational plasticity may shift the paradigm of computational studies of kinases which assume fixed protonation states. Understanding proton-coupled conformational dynamics may hold a key to further innovation in kinase drug discovery.
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Affiliation(s)
- Cheng-Chieh Tsai
- Department of Pharmaceutical Sciences , University of Maryland School of Pharmacy , Baltimore , Maryland 21201 , United States
| | - Zhi Yue
- Department of Pharmaceutical Sciences , University of Maryland School of Pharmacy , Baltimore , Maryland 21201 , United States
| | - Jana Shen
- Department of Pharmaceutical Sciences , University of Maryland School of Pharmacy , Baltimore , Maryland 21201 , United States
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19
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Ahuja LG, Aoto PC, Kornev AP, Veglia G, Taylor SS. Dynamic allostery-based molecular workings of kinase:peptide complexes. Proc Natl Acad Sci U S A 2019; 116:15052-15061. [PMID: 31285328 PMCID: PMC6660753 DOI: 10.1073/pnas.1900163116] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
A dense interplay between structure and dynamics underlies the working of proteins, especially enzymes. Protein kinases are molecular switches that are optimized for their regulation rather than catalytic turnover rates. Using long-simulations dynamic allostery analysis, this study describes an exploration of the dynamic kinase:peptide complex. We have used protein kinase A (PKA) as a model system as a generic prototype of the protein kinase superfamily of signaling enzymes. Our results explain the role of dynamic coupling of active-site residues that must work in coherence to provide for a successful activation or inhibition response from the kinase. Amino acid networks-based community analysis allows us to ponder the conformational entropy of the kinase:nucleotide:peptide ternary complex. We use a combination of 7 peptides that include 3 types of PKA-binding partners: Substrates, products, and inhibitors. The substrate peptides provide for dynamic insights into the enzyme:substrate complex, while the product phospho-peptide allows for accessing modes of enzyme:product release. Mapping of allosteric communities onto the PKA structure allows us to locate the more unvarying and flexible dynamic regions of the kinase. These distributions, when correlated with the structural elements of the kinase core, allow for a detailed exploration of key dynamics-based signatures that could affect peptide recognition and binding at the kinase active site. These studies provide a unique dynamic allostery-based perspective to kinase:peptide complexes that have previously been explored only in a structural or thermodynamic context.
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Affiliation(s)
- Lalima G Ahuja
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093;
| | - Phillip C Aoto
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
| | - Alexandr P Kornev
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
| | - Gianluigi Veglia
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455
| | - Susan S Taylor
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093;
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093
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20
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Boczek EE, Luo Q, Dehling M, Röpke M, Mader SL, Seidl A, Kaila VRI, Buchner J. Autophosphorylation activates c-Src kinase through global structural rearrangements. J Biol Chem 2019; 294:13186-13197. [PMID: 31331936 DOI: 10.1074/jbc.ra119.008199] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 07/15/2019] [Indexed: 11/06/2022] Open
Abstract
The prototypical kinase c-Src plays an important role in numerous signal transduction pathways, where its activity is tightly regulated by two phosphorylation events. Phosphorylation at a specific tyrosine by C-terminal Src kinase inactivates c-Src, whereas autophosphorylation is essential for the c-Src activation process. However, the structural consequences of the autophosphorylation process still remain elusive. Here we investigate how the structural landscape of c-Src is shaped by nucleotide binding and phosphorylation of Tyr416 using biochemical experiments, hydrogen/deuterium exchange MS, and atomistic molecular simulations. We show that the initial steps of kinase activation involve large rearrangements in domain orientation. The kinase domain is highly dynamic and has strong cross-talk with the regulatory domains, which are displaced by autophosphorylation. Although the regulatory domains become more flexible and detach from the kinase domain because of autophosphorylation, the kinase domain gains rigidity, leading to stabilization of the ATP binding site and a 4-fold increase in enzymatic activity. Our combined results provide a molecular framework of the central steps in c-Src kinase regulation process with possible implications for understanding general kinase activation mechanisms.
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Affiliation(s)
- Edgar E Boczek
- Center for Integrated Protein Science, Department Chemie, Technische Universität München, 85748 Garching, Germany; Max Planck Institute of Molecular Cell Biology and Genetics, 01307 Dresden, Germany
| | - Qi Luo
- Center for Integrated Protein Science, Department Chemie, Technische Universität München, 85748 Garching, Germany; Soft Matter Research Center and Department of Chemistry, Zhejiang University, Zhejiang Sheng 310027, China
| | - Marco Dehling
- Center for Integrated Protein Science, Department Chemie, Technische Universität München, 85748 Garching, Germany; Novartis Biologics Technical Development and Manufacturing, Sandoz Biopharmaceuticals, Hexal AG, 82041 Oberhaching, Germany
| | - Michael Röpke
- Center for Integrated Protein Science, Department Chemie, Technische Universität München, 85748 Garching, Germany
| | - Sophie L Mader
- Center for Integrated Protein Science, Department Chemie, Technische Universität München, 85748 Garching, Germany
| | - Andreas Seidl
- Novartis Biologics Technical Development and Manufacturing, Sandoz Biopharmaceuticals, Hexal AG, 82041 Oberhaching, Germany
| | - Ville R I Kaila
- Center for Integrated Protein Science, Department Chemie, Technische Universität München, 85748 Garching, Germany.
| | - Johannes Buchner
- Center for Integrated Protein Science, Department Chemie, Technische Universität München, 85748 Garching, Germany.
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21
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Taylor SS, Meharena HS, Kornev AP. Evolution of a dynamic molecular switch. IUBMB Life 2019; 71:672-684. [PMID: 31059206 DOI: 10.1002/iub.2059] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 04/18/2019] [Indexed: 12/20/2022]
Abstract
Eukaryotic protein kinases (EPKs) regulate almost every biological process and have evolved to be dynamic molecular switches; this is in stark contrast to metabolic enzymes, which have evolved to be efficient catalysts. In particular, the highly conserved active site of every EPK is dynamically and transiently assembled by a process that is highly regulated and unique for every protein kinase. We review here the essential features of the kinase core, focusing on the conserved motifs and residues that are embedded in every kinase. We explore, in particular, how the hydrophobic core architecture specifically drives the dynamic assembly of the regulatory spine and consequently the organization of the active site where the γ-phosphate of ATP is positioned by a convergence of conserved motifs including a conserved regulatory triad for transfer to a protein substrate. In conclusion, we show how the flanking N- and C-terminal tails often classified as intrinsically disordered regions, as well as flanking domains, contribute in a highly kinase-specific manner to the regulation of the conserved kinase core. Understanding this process as well as how one kinase activates another remains as two of the big challenges for the kinase signaling community. © 2019 IUBMB Life, 71(6):672-684, 2019.
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Affiliation(s)
- Susan S Taylor
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA.,Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA, USA
| | - Hiruy S Meharena
- Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Alexandr P Kornev
- Department of Pharmacology, University of California, San Diego, La Jolla, CA, USA
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22
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Gerlits O, Weiss KL, Blakeley MP, Veglia G, Taylor SS, Kovalevsky A. Zooming in on protons: Neutron structure of protein kinase A trapped in a product complex. SCIENCE ADVANCES 2019; 5:eaav0482. [PMID: 30906862 PMCID: PMC6426457 DOI: 10.1126/sciadv.aav0482] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Accepted: 01/31/2019] [Indexed: 05/06/2023]
Abstract
The question vis-à-vis the chemistry of phosphoryl group transfer catalyzed by protein kinases remains a major challenge. The neutron diffraction structure of the catalytic subunit of cAMP-dependent protein kinase (PKA-C) provides a more complete chemical portrait of key proton interactions at the active site. By using a high-affinity protein kinase substrate (PKS) peptide, we captured the reaction products, dephosphorylated nucleotide [adenosine diphosphate (ADP)] and phosphorylated PKS (pPKS), bound at the active site. In the complex, the phosphoryl group of the peptide is protonated, whereas the carboxyl group of the catalytic Asp166 is not. Our structure, including conserved waters, shows how the peptide links the distal parts of the cleft together, creating a network that engages the entire molecule. By comparing slow-exchanging backbone amides to those determined by the NMR analysis of PKA-C with ADP and inhibitor peptide (PKI), we identified exchangeable amides that likely distinguish catalytic and inhibited states.
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Affiliation(s)
- Oksana Gerlits
- Bredesen Center, University of Tennessee, Knoxville, TN 37996, USA
| | - Kevin L. Weiss
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Matthew P. Blakeley
- Large Scale Structures Group, Institut Laue-Langevin, Grenoble Cedex 9, 38042, France
| | - Gianluigi Veglia
- Department of Chemistry, University of Minnesota, Minneapolis, MN 55455, USA
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Susan S. Taylor
- Department of Pharmacology, University of California at San Diego, La Jolla, CA 92093, USA
- Department of Chemistry and Biochemistry, University of California at San Diego, La Jolla, CA 92093, USA
| | - Andrey Kovalevsky
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
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23
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Pemmari A, Leppänen T, Paukkeri EL, Eskelinen A, Moilanen T, Moilanen E. Gene expression in adverse reaction to metal debris around metal-on-metal arthroplasty: An RNA-Seq-based study. J Trace Elem Med Biol 2018; 48:149-156. [PMID: 29773173 DOI: 10.1016/j.jtemb.2018.03.014] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 03/15/2018] [Accepted: 03/16/2018] [Indexed: 01/23/2023]
Abstract
Joint replacement surgery is a standard treatment of advanced osteoarthritis (OA). Since 2000, cobalt-chromium (CoCr) metal-on-metal (MoM) implants were widely used in hip arthroplasties. Some patients developed "adverse reaction to metal debris" (ARMD) around the prosthesis, resulting in a need for revision surgery. In the present study, we addressed the pathogenesis of ARMD by genome-wide expression analysis. Pseudosynovial ARMD tissue was obtained from revision surgery of Articular Surface Replacement (ASR, DePuy, Warsaw, IN, USA) hip arthroplasties. Control tissue was 1) OA synovium from primary hip arthroplasties and 2) inflammatory pseudosynovial tissue from metal-on-plastic (MoP) implant revisions. In ARMD tissue, the expression of 1446 genes was significantly increased and that of 1881 decreased as compared to OA synovium. Genes associated with immune response, tissue development and certain leukocyte signaling pathways were enriched in the differently (FC > 2) expressed genes. The network analysis proposed PRKACB, CD2, CD52 and CD53 as the central regulators of the greatest (FC > 10) differences. When ARMD tissue was compared to MoP tissue, the expression of 16 genes was significantly higher and that of 21 lower. Many of these genes were associated with redox homeostasis, metal ion binding and transport, macrophage activation and apoptosis. Interestingly, genes central to myofibroblast (AEBP1 and DES) and osteoclast (CCL21, TREM2 and CKB) development were upregulated in the MoP tissue. In network analysis, IL8, NQO1, GSTT1 and HMOX1 were identified as potential central regulators of the changes. In conclusion, excessive amounts of CoCr debris produced by MoM hip implants induces in a group of patients a unique adverse reaction characterized with enhanced expression of genes associated with inflammation, redox homeostasis, metal ion binding and transport, macrophage activation and apoptosis.
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Affiliation(s)
- Antti Pemmari
- The Immunopharmacology Research Group, Faculty of Medicine and Life Sciences, University of Tampere and Tampere University Hospital, Tampere, Finland
| | - Tiina Leppänen
- The Immunopharmacology Research Group, Faculty of Medicine and Life Sciences, University of Tampere and Tampere University Hospital, Tampere, Finland
| | - Erja-Leena Paukkeri
- The Immunopharmacology Research Group, Faculty of Medicine and Life Sciences, University of Tampere and Tampere University Hospital, Tampere, Finland
| | | | - Teemu Moilanen
- The Immunopharmacology Research Group, Faculty of Medicine and Life Sciences, University of Tampere and Tampere University Hospital, Tampere, Finland; Coxa Hospital for Joint Replacement, Tampere, Finland
| | - Eeva Moilanen
- The Immunopharmacology Research Group, Faculty of Medicine and Life Sciences, University of Tampere and Tampere University Hospital, Tampere, Finland.
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24
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Abstract
It has been recognized that myocardial apoptosis is one major factor in the development of heart dysfunction and autophagy has been shown to influence the apoptosis. In previous studies, we reported that anti-β1-adrenergic receptor autoantibodies (β1-AABs) decreased myocardial autophagy, but the role of decreased autophagy in cardiomyocyte apoptosis remains unclear. In the present study, we used a β1-AAB-immunized rat model to investigate the role of decreased autophagy in cardiomyocyte apoptosis. We reported that the level of autophagic flux increased early and then decreased in an actively β1-AAB-immunized rat model. Rapamycin, an mTOR inhibitor, restored myocardial apoptosis in the presence of β1-AABs. Further, we found that the early increase of autophagy was an adaptive stress response that is possibly unrelated to β1-AR, and the activation of the β1-AR and PKA contributed to late decreased autophagy. Then, after upregulating or inhibiting autophagy with rapamycin, Atg5 overexpression adenovirus or 3-methyladenine in cultured primary neonatal rat cardiomyocytes, we found that autophagy decline promoted myocardial apoptosis effectively through the mitochondrial apoptotic pathway. In conclusion, the reduction of apoptosis through the proper regulation of autophagy may be important for treating patients with β1-AAB-positive heart dysfunction.
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25
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Cheng F, Ramos da Silva S, Huang IC, Jung JU, Gao SJ. Suppression of Zika Virus Infection and Replication in Endothelial Cells and Astrocytes by PKA Inhibitor PKI 14-22. J Virol 2018; 92:JVI.02019-17. [PMID: 29212931 PMCID: PMC5790943 DOI: 10.1128/jvi.02019-17] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 11/28/2017] [Indexed: 02/05/2023] Open
Abstract
The recent outbreak of Zika virus (ZIKV), a reemerging flavivirus, and its associated neurological disorders, such as Guillain-Barré (GB) syndrome and microcephaly, have generated an urgent need to develop effective ZIKV vaccines and therapeutic agents. Here, we used human endothelial cells and astrocytes, both of which represent key cell types for ZIKV infection, to identify potential inhibitors of ZIKV replication. Because several pathways, including the AMP-activated protein kinase (AMPK), protein kinase A (PKA), and mitogen-activated protein kinase (MAPK) signaling pathways, have been reported to play important roles in flavivirus replication, we tested inhibitors and agonists of these pathways for their effects on ZIKV replication. We identified the PKA inhibitor PKI 14-22 (PKI) to be a potent inhibitor of ZIKV replication. PKI effectively suppressed the replication of ZIKV from both the African and Asian/American lineages with a high efficiency and minimal cytotoxicity. While ZIKV infection does not induce PKA activation, endogenous PKA activity is essential for supporting ZIKV replication. Interestingly, in addition to PKA, PKI also inhibited another unknown target(s) to block ZIKV replication. PKI inhibited ZIKV replication at the postentry stage by preferentially affecting negative-sense RNA synthesis as well as viral protein translation. Together, these results have identified a potential inhibitor of ZIKV replication which could be further explored for future therapeutic application.IMPORTANCE There is an urgent need to develop effective vaccines and therapeutic agents against Zika virus (ZIKV) infection, a reemerging flavivirus associated with neurological disorders, including Guillain-Barré (GB) syndrome and microcephaly. By screening for inhibitors of several cellular pathways, we have identified the PKA inhibitor PKI 14-22 (PKI) to be a potent inhibitor of ZIKV replication. We show that PKI effectively suppresses the replication of all ZIKV strains tested with minimal cytotoxicity to human endothelial cells and astrocytes, two key cell types for ZIKV infection. Furthermore, we show that PKI inhibits ZIKV negative-sense RNA synthesis and viral protein translation. This study has identified a potent inhibitor of ZIKV infection which could be further explored for future therapeutic application.
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Affiliation(s)
- Fan Cheng
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Suzane Ramos da Silva
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - I-Chueh Huang
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Jae U Jung
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
| | - Shou-Jiang Gao
- Department of Molecular Microbiology and Immunology, Keck School of Medicine, University of Southern California, Los Angeles, California, USA
- Laboratory of Human Virology and Oncology, Shantou University Medical College, Shantou, Guangdong, People's Republic of China
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Plaza-Menacho I. Structure and function of RET in multiple endocrine neoplasia type 2. Endocr Relat Cancer 2018; 25:T79-T90. [PMID: 29175871 DOI: 10.1530/erc-17-0354] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 11/23/2017] [Indexed: 12/31/2022]
Abstract
It has been twenty-five years since the discovery of oncogenic germline RET mutations as the cause of multiple endocrine neoplasia type 2 (MEN2). Intensive work over the last two and a half decades on RET genetics, signaling and cell biology has provided the current bases for the genotype-phenotype and functional correlations within this cancer syndrome. On the contrary, the structural and molecular basis for RET tyrosine kinase domain activation and oncogenic deregulation has remained largely elusive. Recent studies with a strong crystallographic and biochemical focus have started to elucidate key insights into such molecular and atomic details revealing unexpected and private mechanisms of actions and molecular determinants not previously envisioned. This review focuses on the structure and function of the RET receptor, and in particular, on what a more detailed view of the protein itself and what the current structural and molecular information tell us about the genotype and phenotype relationships in the cancer syndrome MEN2.
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Affiliation(s)
- Iván Plaza-Menacho
- KinasesProtein Phosphorylation and Cancer, Structural Biology Programme, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
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Singh I, Singh S, Verma V, Uversky VN, Chandra R. In silico evaluation of the resistance of the T790M variant of epidermal growth factor receptor kinase to cancer drug Erlotinib. J Biomol Struct Dyn 2017; 36:4209-4219. [PMID: 29183267 DOI: 10.1080/07391102.2017.1411293] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Epidermal growth factor receptor kinase is implicated in cancer development due to either overexpression or activation variants in its functional intracellular kinase domain. Threonine to methionine (Thr 790 Met) is one such variant observed commonly in patients showing resistance to kinase inhibitor drug Erlotinib. Two mechanisms for resistance have been proposed (1) steric hindrance and (2) enhanced binding to ATP. In this study, we employed molecular dynamics simulations and studied both the mechanisms. Extensive simulations and free energy of binding analyses has shown that steric hindrance does not explain appropriately the mechanism for resistance against Erlotinib therapy for this variant. It has been observed that conformational switching from an intermediate intrinsically disordered C-helix conformation is required for completion of the kinase's catalytic cycle. Our study substantiates that T790M variant has greater tendency for early transition to this intrinsically disordered C-helix intermediate state. We propose that enhanced catalytic efficiency in addition to enhanced ATP binding explains mechanism of T790M resistance to drug Erlotinib.
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Affiliation(s)
- Inderpal Singh
- a Department of Biotechnology , Shri Mata Vaishno Devi University (SMVDU) , Kakryal , Katra 182320 , Jammu and Kashmir , India.,b Bioinformatics Infrastructure Facility, Department of Biotechnology , Shri Mata Vaishno Devi University (SMVDU) , Kakryal , Katra 182320 , Jammu and Kashmir , India
| | - Shashank Singh
- c Cancer Pharmacology Division, Indian Institute of Integrative Medicine (CSIR-IIIM) , Canal Road, Jammu 180001 , Jammu and Kashmir , India
| | - Vijeshwar Verma
- a Department of Biotechnology , Shri Mata Vaishno Devi University (SMVDU) , Kakryal , Katra 182320 , Jammu and Kashmir , India.,b Bioinformatics Infrastructure Facility, Department of Biotechnology , Shri Mata Vaishno Devi University (SMVDU) , Kakryal , Katra 182320 , Jammu and Kashmir , India
| | - Vladimir N Uversky
- d Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute , Morsani College of Medicine, University of South Florida, University of South Florida , Tampa , FL , USA.,e Laboratory of New Methods in Biology, Institute for Biological Instrumentation , Russian Academy of Sciences , 142290 Pushchino , Moscow Region , Russia
| | - Ratna Chandra
- a Department of Biotechnology , Shri Mata Vaishno Devi University (SMVDU) , Kakryal , Katra 182320 , Jammu and Kashmir , India
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28
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Metal coordination in kinases and pseudokinases. Biochem Soc Trans 2017; 45:653-663. [PMID: 28620027 DOI: 10.1042/bst20160327] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 03/10/2017] [Accepted: 03/15/2017] [Indexed: 11/17/2022]
Abstract
Protein phosphorylation, mediated by protein kinases, is a key event in the regulation of eukaryotic signal transduction. The majority of eukaryotic protein kinases perform phosphoryl transfer, assisted by two divalent metal ions. About 10% of all human protein kinases are, however, thought to be catalytically inactive. These kinases lack conserved residues of the kinase core and are classified as pseudokinases. Yet, it has been demonstrated that pseudokinases are critically involved in biological functions. Here, we show how pseudokinases have developed strategies by modifying amino acid residues in order to achieve stable, active-like conformations. This includes binding of the co-substrate ATP in a two metal-, one metal- or even no metal-binding mode. Examples of the respective pseudokinases are provided on a structural basis and compared with a canonical protein kinase, Protein Kinase A. Moreover, the functional roles of both independent metal-binding sites, Me1 and Me2, are discussed. Lack of phosphotransferase activity does not implicate a loss of function and can easily point to alternative roles of pseudokinases, i.e. acting as switches or scaffolds, and having evolved as components crucial for cellular cross-talk and signaling. Interestingly, pseudokinases are present in all kingdoms of life and their specific roles remain enigmatic. More studies are needed to unravel the crucial functions of those interesting proteins.
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A Novel Phosphoregulatory Switch Controls the Activity and Function of the Major Catalytic Subunit of Protein Kinase A in Aspergillus fumigatus. mBio 2017; 8:mBio.02319-16. [PMID: 28174315 PMCID: PMC5296607 DOI: 10.1128/mbio.02319-16] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Invasive aspergillosis (IA), caused by the filamentous fungal pathogen Aspergillus fumigatus, is a major cause of death among immunocompromised patients. The cyclic AMP/protein kinase A (PKA) signaling pathway is essential for hyphal growth and virulence of A. fumigatus, but the mechanism of regulation of PKA remains largely unknown. Here, we discovered a novel mechanism for the regulation of PKA activity in A. fumigatus via phosphorylation of key residues within the major catalytic subunit, PkaC1. Phosphopeptide enrichment and tandem mass spectrometry revealed the phosphorylation of PkaC1 at four sites (S175, T331, T333, and T337) with implications for important and diverse roles in the regulation of A. fumigatus PKA. While the phosphorylation at one of the residues (T333) is conserved in other species, the identification of three other residues represents previously unknown PKA phosphoregulation in A. fumigatus Site-directed mutagenesis of the phosphorylated residues to mimic or prevent phosphorylation revealed dramatic effects on kinase activity, growth, conidiation, cell wall stress response, and virulence in both invertebrate and murine infection models. Three-dimensional structural modeling of A. fumigatus PkaC1 substantiated the positive or negative regulatory roles for specific residues. Suppression of PKA activity also led to downregulation of PkaC1 protein levels in an apparent novel negative-feedback mechanism. Taken together, we propose a model in which PkaC1 phosphorylation both positively and negatively modulates its activity. These findings pave the way for future discovery of fungus-specific aspects of this key signaling network. IMPORTANCE Our understanding of signal transduction networks in pathogenic fungi is limited, despite the increase in invasive fungal infections and rising mortality rates in the immunosuppressed patient population. Because PKA is known to be essential for hyphal growth and virulence of A. fumigatus, we sought to identify fungus-specific regulatory mechanisms governing PKA activity. In this study, we identify, for the first time, a novel mechanism for the regulation of PKA signaling in which differential phosphorylation of the PkaC1 catalytic subunit can lead to either positive or negative regulation of activity. Furthermore, we show that inactivation of PKA signaling leads to downregulation of catalytic subunit protein levels in a negative-feedback mechanism distinct from expression patterns previously reported in the yeasts. Our findings represent a divergence in the regulation of PKA signaling in A. fumigatus, which could potentially be exploited as a target and also open the avenue for discovery of fungus-specific downstream effectors of PKA.
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Beenstock J, Mooshayef N, Engelberg D. How Do Protein Kinases Take a Selfie (Autophosphorylate)? Trends Biochem Sci 2016; 41:938-953. [DOI: 10.1016/j.tibs.2016.08.006] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2016] [Revised: 07/13/2016] [Accepted: 08/02/2016] [Indexed: 12/18/2022]
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cAMP-dependent protein kinase (PKA) complexes probed by complementary differential scanning fluorimetry and ion mobility-mass spectrometry. Biochem J 2016; 473:3159-75. [PMID: 27444646 PMCID: PMC5095912 DOI: 10.1042/bcj20160648] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Accepted: 07/21/2016] [Indexed: 12/21/2022]
Abstract
cAMP-dependent protein kinase (PKA) is an archetypal biological signaling module and a model for understanding the regulation of protein kinases. In the present study, we combine biochemistry with differential scanning fluorimetry (DSF) and ion mobility–mass spectrometry (IM–MS) to evaluate effects of phosphorylation and structure on the ligand binding, dynamics and stability of components of heteromeric PKA protein complexes in vitro. We uncover dynamic, conformationally distinct populations of the PKA catalytic subunit with distinct structural stability and susceptibility to the physiological protein inhibitor PKI. Native MS of reconstituted PKA R2C2 holoenzymes reveals variable subunit stoichiometry and holoenzyme ablation by PKI binding. Finally, we find that although a ‘kinase-dead’ PKA catalytic domain cannot bind to ATP in solution, it interacts with several prominent chemical kinase inhibitors. These data demonstrate the combined power of IM–MS and DSF to probe PKA dynamics and regulation, techniques that can be employed to evaluate other protein-ligand complexes, with broad implications for cellular signaling.
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32
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Xie S, Jin N, Gu J, Shi J, Sun J, Chu D, Zhang L, Dai C, Gu J, Gong C, Iqbal K, Liu F. O-GlcNAcylation of protein kinase A catalytic subunits enhances its activity: a mechanism linked to learning and memory deficits in Alzheimer's disease. Aging Cell 2016; 15:455-64. [PMID: 26840030 PMCID: PMC4854926 DOI: 10.1111/acel.12449] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/04/2016] [Indexed: 02/03/2023] Open
Abstract
Alzheimer's disease (AD) is characterized clinically by memory loss and cognitive decline. Protein kinase A (PKA)‐CREB signaling plays a critical role in learning and memory. It is known that glucose uptake and O‐GlcNAcylation are reduced in AD brain. In this study, we found that PKA catalytic subunits (PKAcs) were posttranslationally modified by O‐linked N‐acetylglucosamine (O‐GlcNAc). O‐GlcNAcylation regulated the subcellular location of PKAcα and PKAcβ and enhanced their kinase activity. Upregulation of O‐GlcNAcylation in metabolically active rat brain slices by O‐(2‐acetamido‐2‐deoxy‐d‐glucopyranosylidenamino) N‐phenylcarbamate (PUGNAc), an inhibitor of N‐acetylglucosaminidase, increased the phosphorylation of tau at the PKA site, Ser214, but not at the non‐PKA site, Thr205. In contrast, in rat and mouse brains, downregulation of O‐GlcNAcylation caused decreases in the phosphorylation of CREB at Ser133 and of tau at Ser214, but not at Thr205. Reduction in O‐GlcNAcylation through intracerebroventricular injection of 6‐diazo‐5‐oxo‐l‐norleucine (DON), the inhibitor of glutamine fructose‐6‐phosphate amidotransferase, suppressed PKA‐CREB signaling and impaired learning and memory in mice. These results indicate that in addition to cAMP and phosphorylation, O‐GlcNAcylation is a novel mechanism that regulates PKA‐CREB signaling. Downregulation of O‐GlcNAcylation suppresses PKA‐CREB signaling and consequently causes learning and memory deficits in AD.
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Affiliation(s)
- Shutao Xie
- Jiangsu Key Laboratory of Neuroregeneration Co‐innovation Center of Neuroregeneration Nantong University Nantong Jiangsu 226001 China
- Department of Neurochemistry Inge Grundke‐Iqbal Research Floor New York State Institute for Basic Research in Developmental Disabilities Staten Island New York 10314 USA
| | - Nana Jin
- Jiangsu Key Laboratory of Neuroregeneration Co‐innovation Center of Neuroregeneration Nantong University Nantong Jiangsu 226001 China
- Department of Neurochemistry Inge Grundke‐Iqbal Research Floor New York State Institute for Basic Research in Developmental Disabilities Staten Island New York 10314 USA
| | - Jianlan Gu
- Jiangsu Key Laboratory of Neuroregeneration Co‐innovation Center of Neuroregeneration Nantong University Nantong Jiangsu 226001 China
- Department of Neurochemistry Inge Grundke‐Iqbal Research Floor New York State Institute for Basic Research in Developmental Disabilities Staten Island New York 10314 USA
| | - Jianhua Shi
- Jiangsu Key Laboratory of Neuroregeneration Co‐innovation Center of Neuroregeneration Nantong University Nantong Jiangsu 226001 China
| | - Jianming Sun
- Jiangsu Key Laboratory of Neuroregeneration Co‐innovation Center of Neuroregeneration Nantong University Nantong Jiangsu 226001 China
| | - Dandan Chu
- Jiangsu Key Laboratory of Neuroregeneration Co‐innovation Center of Neuroregeneration Nantong University Nantong Jiangsu 226001 China
| | - Liang Zhang
- Department of Neurochemistry Inge Grundke‐Iqbal Research Floor New York State Institute for Basic Research in Developmental Disabilities Staten Island New York 10314 USA
| | - Chun‐ling Dai
- Department of Neurochemistry Inge Grundke‐Iqbal Research Floor New York State Institute for Basic Research in Developmental Disabilities Staten Island New York 10314 USA
| | - Jin‐hua Gu
- Jiangsu Key Laboratory of Neuroregeneration Co‐innovation Center of Neuroregeneration Nantong University Nantong Jiangsu 226001 China
| | - Cheng‐Xin Gong
- Department of Neurochemistry Inge Grundke‐Iqbal Research Floor New York State Institute for Basic Research in Developmental Disabilities Staten Island New York 10314 USA
| | - Khalid Iqbal
- Department of Neurochemistry Inge Grundke‐Iqbal Research Floor New York State Institute for Basic Research in Developmental Disabilities Staten Island New York 10314 USA
| | - Fei Liu
- Jiangsu Key Laboratory of Neuroregeneration Co‐innovation Center of Neuroregeneration Nantong University Nantong Jiangsu 226001 China
- Department of Neurochemistry Inge Grundke‐Iqbal Research Floor New York State Institute for Basic Research in Developmental Disabilities Staten Island New York 10314 USA
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Molecular Dynamics Simulations and Classical Multidimensional Scaling Unveil New Metastable States in the Conformational Landscape of CDK2. PLoS One 2016; 11:e0154066. [PMID: 27100206 PMCID: PMC4839568 DOI: 10.1371/journal.pone.0154066] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 04/07/2016] [Indexed: 01/04/2023] Open
Abstract
Protein kinases are key regulatory nodes in cellular networks and their function has been shown to be intimately coupled with their structural flexibility. However, understanding the key structural mechanisms of large conformational transitions remains a difficult task. CDK2 is a crucial regulator of cell cycle. Its activity is finely tuned by Cyclin E/A and the catalytic segment phosphorylation, whereas its deregulation occurs in many types of cancer. ATP competitive inhibitors have failed to be approved for clinical use due to toxicity issues raised by a lack of selectivity. However, in the last few years type III allosteric inhibitors have emerged as an alternative strategy to selectively modulate CDK2 activity. In this study we have investigated the conformational variability of CDK2. A low dimensional conformational landscape of CDK2 was modeled using classical multidimensional scaling on a set of 255 crystal structures. Microsecond-scale plain and accelerated MD simulations were used to populate this landscape by using an out-of-sample extension of multidimensional scaling. CDK2 was simulated in the apo-form and in complex with the allosteric inhibitor 8-anilino-1-napthalenesulfonic acid (ANS). The apo-CDK2 landscape analysis showed a conformational equilibrium between an Src-like inactive conformation and an active-like form. These two states are separated by different metastable states that share hybrid structural features with both forms of the kinase. In contrast, the CDK2/ANS complex landscape is compatible with a conformational selection picture where the binding of ANS in proximity of the αC helix causes a population shift toward the inactive conformation. Interestingly, the new metastable states could enlarge the pool of candidate structures for the development of selective allosteric CDK2 inhibitors. The method here presented should not be limited to the CDK2 case but could be used to systematically unmask similar mechanisms throughout the human kinome.
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Pucheta-Martínez E, Saladino G, Morando MA, Martinez-Torrecuadrada J, Lelli M, Sutto L, D’Amelio N, Gervasio FL. An Allosteric Cross-Talk Between the Activation Loop and the ATP Binding Site Regulates the Activation of Src Kinase. Sci Rep 2016; 6:24235. [PMID: 27063862 PMCID: PMC4827121 DOI: 10.1038/srep24235] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 03/22/2016] [Indexed: 11/09/2022] Open
Abstract
Phosphorylation of the activation loop is a fundamental step in the activation of most protein kinases. In the case of the Src tyrosine kinase, a prototypical kinase due to its role in cancer and its historic importance, phosphorylation of tyrosine 416 in the activation loop is known to rigidify the structure and contribute to the switch from the inactive to a fully active form. However, whether or not phosphorylation is able per-se to induce a fully active conformation, that efficiently binds ATP and phosphorylates the substrate, is less clear. Here we employ a combination of solution NMR and enhanced-sampling molecular dynamics simulations to fully map the effects of phosphorylation and ATP/ADP cofactor loading on the conformational landscape of Src tyrosine kinase. We find that both phosphorylation and cofactor binding are needed to induce a fully active conformation. What is more, we find a complex interplay between the A-loop and the hinge motion where the phosphorylation of the activation-loop has a significant allosteric effect on the dynamics of the C-lobe.
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Affiliation(s)
| | - Giorgio Saladino
- Department of Chemistry, University College London, London WC1E 6BT, United Kingdom
- Research Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, United Kingdom
| | - Maria Agnese Morando
- Center of Technological Development in Health, Oswaldo Cruz Foundation (Fiocruz), Rio de Janeiro, Brazil
| | - Jorge Martinez-Torrecuadrada
- Structural Biology and Biocomputing Programme, Spanish National Cancer Research Centre (CNIO), 28029, Madrid, Spain
| | - Moreno Lelli
- Centre de RMN à Très Hauts Champs, Institut de Sciences Analytiques, (CNRS/ENS Lyon/Universitè CB Lyon 1), 69100 Villeurbanne, France
| | - Ludovico Sutto
- Research Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, United Kingdom
| | - Nicola D’Amelio
- Department of Chemistry, University College London, London WC1E 6BT, United Kingdom
| | - Francesco Luigi Gervasio
- Department of Chemistry, University College London, London WC1E 6BT, United Kingdom
- Research Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, United Kingdom
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Xu J, Lee Y, Beamer LJ, Van Doren SR. Phosphorylation in the catalytic cleft stabilizes and attracts domains of a phosphohexomutase. Biophys J 2015; 108:325-37. [PMID: 25606681 DOI: 10.1016/j.bpj.2014.12.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Revised: 11/22/2014] [Accepted: 12/03/2014] [Indexed: 11/18/2022] Open
Abstract
Phosphorylation can modulate the activities of enzymes. The phosphoryl donor in the catalytic cleft of α-D-phosphohexomutases is transiently dephosphorylated while the reaction intermediate completes a 180° reorientation within the cleft. The phosphorylated form of 52 kDa bacterial phosphomannomutase/phosphoglucomutase is less accessible to dye or protease, more stable to chemical denaturation, and widely stabilized against NMR-detected hydrogen exchange across the core of domain 3 to juxtaposed domain 4 (each by ≥ 1.3 kcal/mol) and parts of domains 1 and 2. However, phosphorylation accelerates hydrogen exchange in specific regions of domains 1 and 2, including a metal-binding residue in the active site. Electrostatic field lines reveal attraction across the catalytic cleft between phosphorylated Ser-108 and domain 4, but repulsion when Ser-108 is dephosphorylated. Molecular dynamics (MD) simulated the dephosphorylated form to be expanded due to enhanced rotational freedom of domain 4. The contacts and fluctuations of the MD trajectories enabled correct simulation of more than 80% of sites that undergo either protection or deprotection from hydrogen exchange due to phosphorylation. Electrostatic attraction in the phosphorylated enzyme accounts for 1) domain 4 drawing closer to domains 1 and 3; 2) decreased accessibility; and 3) increased stability within these domains. The electrostriction due to phosphorylation may help capture substrate, whereas the opening of the cleft upon transient dephosphorylation allows rotation of the intermediate. The long-range effects of phosphorylation on hydrogen exchange parallel reports on protein kinases, suggesting a conceptual link among these multidomain, phosphoryl transfer enzymes.
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Affiliation(s)
- Jia Xu
- Department of Biochemistry, University of Missouri, Columbia, Missouri
| | - Yingying Lee
- Department of Biochemistry, University of Missouri, Columbia, Missouri
| | - Lesa J Beamer
- Department of Biochemistry, University of Missouri, Columbia, Missouri
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36
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Ge X, Milenkovic L, Suyama K, Hartl T, Purzner T, Winans A, Meyer T, Scott MP. Phosphodiesterase 4D acts downstream of Neuropilin to control Hedgehog signal transduction and the growth of medulloblastoma. eLife 2015; 4. [PMID: 26371509 PMCID: PMC4569902 DOI: 10.7554/elife.07068] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2015] [Accepted: 08/26/2015] [Indexed: 12/22/2022] Open
Abstract
Alterations in Hedgehog (Hh) signaling lead to birth defects and cancers including medulloblastoma, the most common pediatric brain tumor. Although inhibitors targeting the membrane protein Smoothened suppress Hh signaling, acquired drug resistance and tumor relapse call for additional therapeutic targets. Here we show that phosphodiesterase 4D (PDE4D) acts downstream of Neuropilins to control Hh transduction and medulloblastoma growth. PDE4D interacts directly with Neuropilins, positive regulators of Hh pathway. The Neuropilin ligand Semaphorin3 enhances this interaction, promoting PDE4D translocation to the plasma membrane and cAMP degradation. The consequent inhibition of protein kinase A (PKA) enhances Hh transduction. In the developing cerebellum, genetic removal of Neuropilins reduces Hh signaling activity and suppresses proliferation of granule neuron precursors. In mouse medulloblastoma allografts, PDE4D inhibitors suppress Hh transduction and inhibit tumor growth. Our findings reveal a new regulatory mechanism of Hh transduction, and highlight PDE4D as a promising target to treat Hh-related tumors. DOI:http://dx.doi.org/10.7554/eLife.07068.001 A communication system in cells called the Hedgehog signaling pathway plays an essential role in the formation of tissues and organs in animal embryos. The activity of the pathway is carefully controlled during development and if Hedgehog signaling is disrupted it can lead to developmental defects and particular types of cancer. Some of these cancers can be treated with a drug called vismodegib, which targets a particular molecule in the Hedgehog signaling pathway. However, tumor cells can become resistant to this drug, so researchers are hoping to find new therapies that target other aspects of the signaling pathway. Hedgehog signaling promotes the division of brain cells called granule neuron precursor cells (or GNP cells for short). If the signaling pathway is over-active it can trigger the GNP cells to divide more than they should. This can lead to medulloblastoma, which is the most common type of brain tumor that affects children. Proteins called Neuropilins—which bind to molecules known as Semaphorins—promote Hedgehog signaling and the formation of medulloblastoma, but it was not clear how this works. Here Ge et al. studied the role of Neuropilin in cultured cells and in the cerebellum of mice. The experiments show that Semaphorin 3 promotes the accumulation of an enzyme called PDE4D at the cell membrane. PDE4D interacts with Neuropilin and blocks the activity of another enzyme that normally inhibits Hedgehog signaling. In mice that lack Neuropilin and Semophorin 3, the GNP cells are less able to divide, which leads to abnormal development of the cerebellum. Further experiments show that drugs that target PDE4D inhibit both the Hedgehog pathway and the growth of tumors that are resistant to vismodegib treatment. Ge et al.'s findings uncover a new way in which Hedgehog signaling is regulated and highlight a potential new strategy for treating medulloblastoma and other similar tumors. Current PDE4D inhibitors are associated with severe side effects, so the next challenge is to develop new drugs that have fewer side effects. DOI:http://dx.doi.org/10.7554/eLife.07068.002
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Affiliation(s)
- Xuecai Ge
- Department of Developmental Biology, Department of Genetics, Department of Bioengineering, Stanford University School of Medicine, Stanford, United States
| | - Ljiljana Milenkovic
- Department of Developmental Biology, Department of Genetics, Department of Bioengineering, Stanford University School of Medicine, Stanford, United States
| | - Kaye Suyama
- Department of Developmental Biology, Department of Genetics, Department of Bioengineering, Stanford University School of Medicine, Stanford, United States
| | - Tom Hartl
- Department of Developmental Biology, Department of Genetics, Department of Bioengineering, Stanford University School of Medicine, Stanford, United States
| | - Teresa Purzner
- Department of Developmental Biology, Department of Genetics, Department of Bioengineering, Stanford University School of Medicine, Stanford, United States
| | - Amy Winans
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, United States
| | - Tobias Meyer
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, United States
| | - Matthew P Scott
- Department of Developmental Biology, Department of Genetics, Department of Bioengineering, Stanford University School of Medicine, Stanford, United States
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Wang Q, Zorn JA, Kuriyan J. A structural atlas of kinases inhibited by clinically approved drugs. Methods Enzymol 2015; 548:23-67. [PMID: 25399641 DOI: 10.1016/b978-0-12-397918-6.00002-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The aberrant activation of protein kinases is associated with many human diseases, most notably cancer. Due to this link between kinase deregulation and disease progression, kinases are one of the most targeted protein families for small-molecule inhibition. Within the last 15 years, the U.S. Food and Drug Administration has approved over 20 small-molecule inhibitors of protein kinases for use in the clinic. These inhibitors target the kinase active site and represent the successful hurdling by medicinal chemists of the formidable challenge posed by the high similarity among the active sites of the approximately 500 human kinases. We review the conserved structural features of kinases that are important for inhibitor binding as well as for catalysis. Many clinically approved drugs elicit selectivity by exploiting subtle variation within the kinase active site. We highlight some of the crystallographic studies on the kinase-inhibitor complexes that have provided valuable guidance for the development of these drugs as well as for future drug design efforts.
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Affiliation(s)
- Qi Wang
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, California, USA
| | - Julie A Zorn
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, California, USA
| | - John Kuriyan
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA; California Institute for Quantitative Biosciences, University of California, Berkeley, California, USA; Howard Hughes Medical Institute, University of California, Berkeley, California, USA; Department of Chemistry, University of California, Berkeley, California, USA; Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA.
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38
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Taylor SS, Shaw AS, Kannan N, Kornev AP. Integration of signaling in the kinome: Architecture and regulation of the αC Helix. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1567-74. [PMID: 25891902 DOI: 10.1016/j.bbapap.2015.04.007] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 04/08/2015] [Indexed: 11/27/2022]
Abstract
Eukaryotic protein kinases have evolved to be highly regulated and dynamic molecular switches that are typically kept in an inactive state and then activated in response to extracellular signals. The hallmark signature of an active kinase is a hydrophobic spine called the regulatory (R) spine, which consists of four residues, two in the N-lobe and two in the C-lobe. RS1 is in the catalytic loop, RS2 is the Phe in the DFG motif, RS3 is at the C-terminus of the αC-Helix, and RS4 is at the beginning of β4. Assembly of the R-spine is typically facilitated by phosphorylation of the Activation Loop. The assembled R-spine brings together all of the functional motifs that are essential for transferring the phosphate from ATP to a tethered protein substrate. This includes the G-Loop, which anchors the ATP, the catalytic loop, the DFG motif fused to the Activation Loop, and the αC-Helix. We focus here on the properties of the αC-Helix showing 1) how residues communicate with different parts of the molecule, 2) how it is recruited to the active site as a consequence of assembling of the R-spine, and 3) how it is regulated by linkers/motifs/proteins that lie outside the conserved kinase core. This article is part of a Special Issue entitled: Inhibitors of Protein Kinases.
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Affiliation(s)
- Susan S Taylor
- Department of Pharmacology, University of California, San Diego, 9500 Gilman Drive, 0654, La Jolla, CA 92093, San Diego, USA; Department of Chemistry & Biochemistry, University of California, San Diego, USA
| | - Andrey S Shaw
- Department of Pathology and Immunology, Washington University School of Medicine, 660 South Euclid, Box 8118, St. Louis, MO 63110, USA
| | - Natarajan Kannan
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602, USA
| | - Alexandr P Kornev
- Department of Pharmacology, University of California, San Diego, 9500 Gilman Drive, 0654, La Jolla, CA 92093, San Diego, USA
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39
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Abstract
The quest for ever more selective kinase inhibitors as potential future drugs has yielded a large repertoire of chemical probes that are selective for specific kinase conformations. These probes have been useful tools to obtain structural snapshots of kinase conformational plasticity. Similarly, kinetic and thermodynamic inhibitor binding experiments provide glimpses at the time scales and energetics of conformational interconversions. These experimental insights are complemented by computational predictions of conformational energy landscapes and simulations of conformational transitions and of the process of inhibitors binding to the protein kinase domain. A picture emerges in which highly selective inhibitors capitalize on the dynamic nature of kinases.
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Affiliation(s)
- Michael Tong
- Department
of Pharmacological Sciences, Stony Brook University, Stony Brook, New York 11794, United States
| | - Markus A. Seeliger
- Department
of Pharmacological Sciences, Stony Brook University, Stony Brook, New York 11794, United States
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40
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Kalaivani R, Srinivasan N. A Gaussian network model study suggests that structural fluctuations are higher for inactive states than active states of protein kinases. MOLECULAR BIOSYSTEMS 2015; 11:1079-95. [DOI: 10.1039/c4mb00675e] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Protein kinases participate extensively in cellular signalling. Using Gaussian normal mode analysis of kinases in active and diverse inactive forms, authors show that structural fluctuations are significantly higher in inactive forms and are localized in functionally sensitive sites.
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Affiliation(s)
- Raju Kalaivani
- Molecular Biophysics Unit
- Indian Institute of Science
- Bangalore 560012
- India
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41
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Abstract
A new model of kinase regulation based on the assembly of hydrophobic spines has been proposed. Changes in their positions can explain the mechanism of kinase activation. Here, we examined mutations in human cancer for clues about the regulation of the hydrophobic spines by focusing initially on mutations to Phe. We identified a selected number of Phe mutations in a small group of kinases that included BRAF, ABL1, and the epidermal growth factor receptor. Testing some of these mutations in BRAF, we found that one of the mutations impaired ATP binding and catalytic activity but promoted noncatalytic allosteric functions. Other Phe mutations functioned to promote constitutive catalytic activity. One of these mutations revealed a previously underappreciated hydrophobic surface that functions to position the dynamic regulatory αC-helix. This supports the key role of the C-helix as a signal integration motif for coordinating multiple elements of the kinase to create an active conformation. The importance of the hydrophobic space around the αC-helix was further tested by studying a V600F mutant, which was constitutively active in the absence of the negative charge that is associated with the common V600E mutation. Many hydrophobic mutations strategically localized along the C-helix can thus drive kinase activation.
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42
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Abstract
Protein kinases are dynamically regulated signaling proteins that act as switches in the cell by phosphorylating target proteins. To establish a framework for analyzing linkages between structure, function, dynamics, and allostery in protein kinases, we carried out multiple microsecond-scale molecular-dynamics simulations of protein kinase A (PKA), an exemplar active kinase. We identified residue-residue correlated motions based on the concept of mutual information and used the Girvan-Newman method to partition PKA into structurally contiguous "communities." Most of these communities included 40-60 residues and were associated with a particular protein kinase function or a regulatory mechanism, and well-known motifs based on sequence and secondary structure were often split into different communities. The observed community maps were sensitive to the presence of different ligands and provide a new framework for interpreting long-distance allosteric coupling. Communication between different communities was also in agreement with the previously defined architecture of the protein kinase core based on the "hydrophobic spine" network. This finding gives us confidence in suggesting that community analyses can be used for other protein kinases and will provide an efficient tool for structural biologists. The communities also allow us to think about allosteric consequences of mutations that are linked to disease.
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43
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Structural dynamic analysis of apo and ATP-bound IRAK4 kinase. Sci Rep 2014; 4:5748. [PMID: 25034608 PMCID: PMC4103033 DOI: 10.1038/srep05748] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 07/02/2014] [Indexed: 12/15/2022] Open
Abstract
Interleukin-1 receptor-associated kinases (IRAKs) are Ser/Thr protein kinases that play an important role as signaling mediators in the signal transduction facilitated by the Toll-like receptor (TLR) and interleukin-1 receptor families. Among IRAK family members, IRAK4 is one of the drug targets for diseases related to the TLR and IL-1R signaling pathways. Experimental evidence suggests that the IRAK4 kinase domain is phosphorylated in its activation loop at T342, T345, and S346 in the fully activated state. However, the molecular interactions of subdomains within the active and inactive IRAK4 kinase domain are poorly understood. Hence, we employed a long-range molecular dynamics (MD) simulation to compare apo IRAK4 kinase domains (phosphorylated and unphosphorylated) and ATP-bound phosphorylated IRAK4 kinase domains. The MD results strongly suggested that lobe uncoupling occurs in apo unphosphorylated IRAK4 kinase via the disruption of the R334/T345 and R310/T345 interaction. In addition, apo unphosphorylated trajectory result in high mobility, particularly in the N lobe, activation segment, helix αG, and its adjoining loops. The Asp-Phe-Gly (DFG) and His-Arg-Asp (HRD) conserved kinase motif analysis showed the importance of these motifs in IRAK4 kinase activation. This study provides important information on the structural dynamics of IRAK4 kinase, which will aid in inhibitor development.
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44
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Elbaum MB, Zondlo NJ. OGlcNAcylation and phosphorylation have similar structural effects in α-helices: post-translational modifications as inducible start and stop signals in α-helices, with greater structural effects on threonine modification. Biochemistry 2014; 53:2242-60. [PMID: 24641765 PMCID: PMC4004263 DOI: 10.1021/bi500117c] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
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OGlcNAcylation
and phosphorylation are the major competing intracellular
post-translational modifications of serine and threonine residues.
The structural effects of both post-translational modifications on
serine and threonine were examined within Baldwin model α-helical
peptides (Ac-AKAAAAKAAAAKAAGY-NH2 or Ac-YGAKAAAAKAAAAKAA-NH2). At the N-terminus of an α-helix, both phosphorylation
and OGlcNAcylation stabilized the α-helix relative to the free
hydroxyls, with a larger induced structure for phosphorylation than
for OGlcNAcylation, for the dianionic phosphate than for the monoanionic
phosphate, and for modifications on threonine than for modifications
on serine. Both phosphoserine and phosphothreonine resulted in peptides
more α-helical than alanine at the N-terminus, with dianionic
phosphothreonine the most α-helix-stabilizing residue here.
In contrast, in the interior of the α-helix, both post-translational
modifications were destabilizing with respect to the α-helix,
with the greatest destabilization seen for threonine OGlcNAcylation
at residue 5 and threonine phosphorylation at residue 10, with peptides
containing either post-translational modification existing as random
coils. At the C-terminus, both OGlcNAcylation and phosphorylation
were destabilizing with respect to the α-helix, though the induced
structural changes were less than in the interior of the α-helix.
In general, the structural effects of modifications on threonine were
greater than the effects on serine, because of both the lower α-helical
propensity of Thr and the more defined induced structures upon modification
of threonine than serine, suggesting threonine residues are particularly
important loci for structural effects of post-translational modifications.
The effects of serine and threonine post-translational modifications
are analogous to the effects of proline on α-helices, with the
effects of phosphothreonine being greater than those of proline throughout
the α-helix. These results provide a basis for understanding
the context-dependent structural effects of these competing protein
post-translational modifications.
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Affiliation(s)
- Michael B Elbaum
- Department of Chemistry and Biochemistry, University of Delaware , Newark, Delaware 19716, United States
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45
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Okerberg ES, Brown HE, Minimo L, Alemayehu S, Rosenblum J, Patricelli M, Nomanbhoy T, Kozarich JW. Monitoring native p38α:MK2/3 complexes via trans delivery of an ATP acyl phosphate probe. J Am Chem Soc 2014; 136:4664-9. [PMID: 24601623 DOI: 10.1021/ja4129907] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Here we describe a chemical proteomics strategy using ATP acyl phosphates to measure the formation of a protein:protein complex between p38α and mapkap kinases 2 and/or 3. Formation of the protein:protein complex results in a new probe labeling site on p38α that can be used to quantify the extent of interaction in cell lysates and the equilibrium binding constant for the interaction in vitro. We demonstrate through RNA interference that the labeling site is dependent on formation of the protein:protein complex in cells. Further, we identify that active-site-directed, small-molecule inhibitors of MK2/3 selectively inhibit the heterodimer-dependent probe labeling, whereas p38α inhibitors do not. These findings afford a new method to evaluate p38α and MK2/3 inhibitors within native biological systems and a new tool for improved understanding of p38α signaling pathways.
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Affiliation(s)
- Eric S Okerberg
- ActivX Biosciences, Inc., 11025 North Torrey Pines Road, La Jolla, California 92037, United States
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46
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Brister M, Pandey AK, Bielska AA, Zondlo NJ. OGlcNAcylation and phosphorylation have opposing structural effects in tau: phosphothreonine induces particular conformational order. J Am Chem Soc 2014; 136:3803-16. [PMID: 24559475 PMCID: PMC4004249 DOI: 10.1021/ja407156m] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Indexed: 01/12/2023]
Abstract
Phosphorylation and OGlcNAcylation are dynamic intracellular protein post-translational modifications that frequently are alternatively observed on the same serine and threonine residues. Phosphorylation and OGlcNAcylation commonly occur in natively disordered regions of proteins, and often have opposing functional effects. In the microtubule-associated protein tau, hyperphosphorylation is associated with protein misfolding and aggregation as the neurofibrillary tangles of Alzheimer's disease, whereas OGlcNAcylation stabilizes the soluble form of tau. A series of peptides derived from the proline-rich domain (residues 174-251) of tau was synthesized, with free Ser/Thr hydroxyls, phosphorylated Ser/Thr (pSer/pThr), OGlcNAcylated Ser/Thr, and diethylphosphorylated Ser/Thr. Phosphorylation and OGlcNAcylation were found by CD and NMR to have opposing structural effects on polyproline helix (PPII) formation, with phosphorylation favoring PPII, OGlcNAcylation opposing PPII, and the free hydroxyls intermediate in structure, and with phosphorylation structural effects greater than OGlcNAcylation. For tau196-209, phosphorylation and OGlcNAcylation had similar structural effects, opposing a nascent α-helix. Phosphomimic Glu exhibited PPII-favoring structural effects. Structural changes due to Thr phosphorylation were greater than those of Ser phosphorylation or Glu, with particular conformational restriction as the dianion, with mean (3)JαN = 3.5 Hz (pThr) versus 5.4 Hz (pSer), compared to 7.2, 6.8, and 6.2 Hz for Thr, Ser, and Glu, respectively, values that correlate with the backbone torsion angle ϕ. Dianionic phosphothreonine induced strong phosphothreonine amide protection and downfield amide chemical shifts (δmean = 9.63 ppm), consistent with formation of a stable phosphate-amide hydrogen bond. These data suggest potentially greater structural importance of threonine phosphorylation than serine phosphorylation due to larger induced structural effects.
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Affiliation(s)
| | | | - Agata A. Bielska
- Department of Chemistry and
Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Neal J. Zondlo
- Department of Chemistry and
Biochemistry, University of Delaware, Newark, Delaware 19716, United States
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47
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Jones MR, Liu C, Wilson AK. Molecular dynamics studies of the protein-protein interactions in inhibitor of κB kinase-β. J Chem Inf Model 2014; 54:562-72. [PMID: 24437505 DOI: 10.1021/ci400720n] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Activation of the inhibitor of κB kinase subunit β (IKKβ) oligomer initiates a cascade that results in the translocation of transcription factors involved in mediating immune responses. Dimerization of IKKβ is required for its activation. Coarse-grained and atomistic molecular dynamics simulations were used to investigate the conformation-activity and structure-activity relationships within the oligomer assembly of IKKβ that are impacted upon activation, mutation, and binding of ATP. Intermolecular interactions, free energies, and conformational changes were compared among several conformations, including a monomer, two different dimers, and the tetramer. Modifications to the activation segment induce conformational changes that disrupt dimerization and suggest that the multimeric assembly mediates a global stability for the enzyme that influences the activity of IKKβ.
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Affiliation(s)
- Michael R Jones
- Department of Chemistry and Center for Advanced Scientific Computing and Modeling, University of North Texas , Denton, Texas 76203-5017, United States
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48
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Temmerman K, de Diego I, Pogenberg V, Simon B, Jonko W, Li X, Wilmanns M. A PEF/Y Substrate Recognition and Signature Motif Plays a Critical Role in DAPK-Related Kinase Activity. ACTA ACUST UNITED AC 2014; 21:264-73. [DOI: 10.1016/j.chembiol.2013.12.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 12/06/2013] [Accepted: 12/08/2013] [Indexed: 10/25/2022]
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49
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Abstract
In recent years, HDX-MS (hydrogen–deuterium exchange coupled to MS) on biomolecules has evolved from a niche technique to a powerful method in the investigation of protein dynamics. Protein kinases, in particular, represent an area of active study using this technique owing to their well-characterized protein structures and their relevance to diseases such as cancer, immune disorders and neurodegenerative defects. In the present review, we describe how HDX-MS has revealed important dynamic properties of protein kinases and provided insight into the mechanisms of drug binding.
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50
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Lee Y, Villar MT, Artigues A, Beamer LJ. Promotion of enzyme flexibility by dephosphorylation and coupling to the catalytic mechanism of a phosphohexomutase. J Biol Chem 2014; 289:4674-82. [PMID: 24403075 DOI: 10.1074/jbc.m113.532226] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The enzyme phosphomannomutase/phosphoglucomutase (PMM/PGM) from Pseudomonas aeruginosa catalyzes an intramolecular phosphoryl transfer across its phosphosugar substrates, which are precursors in the synthesis of exoproducts involved in bacterial virulence. Previous structural studies of PMM/PGM have established a key role for conformational change in its multistep reaction, which requires a dramatic 180° reorientation of the intermediate within the active site. Here hydrogen-deuterium exchange by mass spectrometry and small angle x-ray scattering were used to probe the conformational flexibility of different forms of PMM/PGM in solution, including its active, phosphorylated state and the unphosphorylated state that occurs transiently during the catalytic cycle. In addition, the effects of ligand binding were assessed through use of a substrate analog. We found that both phosphorylation and binding of ligand produce significant effects on deuterium incorporation. Phosphorylation of the conserved catalytic serine has broad effects on residues in multiple domains and is supported by small angle x-ray scattering data showing that the unphosphorylated enzyme is less compact in solution. The effects of ligand binding are generally manifested near the active site cleft and at a domain interface that is a site of conformational change. These results suggest that dephosphorylation of the enzyme may play two critical functional roles: a direct role in the chemical step of phosphoryl transfer and secondly through propagation of structural flexibility. We propose a model whereby increased enzyme flexibility facilitates the reorientation of the reaction intermediate, coupling changes in structural dynamics with the unique catalytic mechanism of this enzyme.
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