1
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Zanela TMP, Zangiabadi M, Zhao Y, Underbakke ES. Molecularly imprinted nanoparticles reveal regulatory scaffolding features in Pyk2 tyrosine kinase. RSC Chem Biol 2024; 5:447-453. [PMID: 38725907 PMCID: PMC11078204 DOI: 10.1039/d3cb00228d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2023] [Accepted: 03/13/2024] [Indexed: 05/12/2024] Open
Abstract
Pyk2 is a multi-domain non-receptor tyrosine kinase that serves dual roles as a signaling enzyme and scaffold. Pyk2 activation involves a multi-stage cascade of conformational rearrangements and protein interactions initiated by autophosphorylation of a linker site. Linker phosphorylation recruits Src kinase, and Src-mediated phosphorylation of the Pyk2 activation loop confers full activation. The regulation and accessibility of the initial Pyk2 autophosphorylation site remains unclear. We employed peptide-binding molecularly imprinted nanoparticles (MINPs) to probe the regulatory conformations controlling Pyk2 activation. MINPs differentiating local structure and phosphorylation state revealed that the Pyk2 autophosphorylation site is protected in the autoinhibited state. Activity profiling of Pyk2 variants implicated FERM and linker residues responsible for constraining the autophosphorylation site. MINPs targeting each Src docking site disrupt the higher-order kinase interactions critical for activation complex maturation. Ultimately, MINPs targeting key regulatory motifs establish a useful toolkit for probing successive activational stages in the higher-order Pyk2 signaling complex.
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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
| | - Milad Zangiabadi
- Department of Chemistry, Iowa State University Ames Iowa 50011 USA
| | - Yan Zhao
- Department of Chemistry, Iowa State University Ames Iowa 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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2
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Jiang T, Wan G, Zhang H, Gyawali YP, Underbakke ES, Feng C. Probing Protein Dynamics in Neuronal Nitric Oxide Synthase by Quantitative Cross-Linking Mass Spectrometry. Biochemistry 2023; 62:2232-2237. [PMID: 37459398 PMCID: PMC10529231 DOI: 10.1021/acs.biochem.3c00245] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
Nitric oxide synthase (NOS) is responsible for the biosynthesis of nitric oxide (NO), an important signaling molecule controlling diverse physiological processes such as neurotransmission and vasodilation. Neuronal NOS (nNOS) is a calmodulin (CaM)-controlled enzyme. In the absence of CaM, several intrinsic control elements, along with NADP+ binding, suppress electron transfer across the NOS domains. CaM binding relieves the inhibitory factors to promote the electron transport required for NO production. The regulatory dynamics of nNOS control elements are critical to governing NO signaling, yet mechanistic questions remain, because the intrinsic dynamics of NOS thwart traditional structural biology approaches. Here, we have employed cross-linking mass spectrometry (XL MS) to probe regulatory dynamics in nNOS, focusing on the CaM-responsive control elements. Quantitative XL MS revealed conformational changes differentiating the nNOS reductase (nNOSred) alone, nNOSred with NADP+, nNOS-CaM, and nNOS-CaM with NADP+. We observed distinct effects of CaM vs NADP+ on cross-linking patterns in nNOSred. CaM induces striking global changes, while the impact of NADP+ is primarily localized to the NADPH-binding subdomain. Moreover, CaM increases the abundance of intra-nNOS cross-links that are related to the formation of the inter-CaM-nNOS cross-links. Taken together, these XL MS results demonstrate that CaM and NADP+ site-specifically alter the nNOS conformational landscape.
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Affiliation(s)
- Ting Jiang
- College of Pharmacy, University of New Mexico, Albuquerque, NM 87131
| | - Guanghua Wan
- College of Pharmacy, University of New Mexico, Albuquerque, NM 87131
| | - Haikun Zhang
- College of Pharmacy, University of New Mexico, Albuquerque, NM 87131
| | | | - Eric S. Underbakke
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011
| | - Changjian Feng
- College of Pharmacy, University of New Mexico, Albuquerque, NM 87131
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3
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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4
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Agnew C, Ayaz P, Kashima R, Loving HS, Ghatpande P, Kung JE, Underbakke ES, Shan Y, Shaw DE, Hata A, Jura N. Structural basis for ALK2/BMPR2 receptor complex signaling through kinase domain oligomerization. Nat Commun 2021; 12:4950. [PMID: 34400635 PMCID: PMC8368100 DOI: 10.1038/s41467-021-25248-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 07/30/2021] [Indexed: 01/10/2023] Open
Abstract
Upon ligand binding, bone morphogenetic protein (BMP) receptors form active tetrameric complexes, comprised of two type I and two type II receptors, which then transmit signals to SMAD proteins. The link between receptor tetramerization and the mechanism of kinase activation, however, has not been elucidated. Here, using hydrogen deuterium exchange mass spectrometry (HDX-MS), small angle X-ray scattering (SAXS) and molecular dynamics (MD) simulations, combined with analysis of SMAD signaling, we show that the kinase domain of the type I receptor ALK2 and type II receptor BMPR2 form a heterodimeric complex via their C-terminal lobes. Formation of this dimer is essential for ligand-induced receptor signaling and is targeted by mutations in BMPR2 in patients with pulmonary arterial hypertension (PAH). We further show that the type I/type II kinase domain heterodimer serves as the scaffold for assembly of the active tetrameric receptor complexes to enable phosphorylation of the GS domain and activation of SMADs.
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Affiliation(s)
- Christopher Agnew
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
| | | | - Risa Kashima
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
| | - Hanna S Loving
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Prajakta Ghatpande
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
| | - Jennifer E Kung
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
- Department of Structural Biology, Genentech, Inc., South San Francisco, USA
| | - Eric S Underbakke
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, USA.
| | | | - David E Shaw
- D. E. Shaw Research, New York, NY, USA.
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA.
| | - Akiko Hata
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA
- Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA, USA
| | - Natalia Jura
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA, USA.
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA.
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5
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Li X, Palhano Zanela TM, Underbakke ES, Zhao Y. Controlling Kinase Activities by Selective Inhibition of Peptide Substrates. J Am Chem Soc 2021; 143:639-643. [DOI: 10.1021/jacs.0c11566] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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6
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Khatiwada B, Purslow JA, Underbakke ES, Venditti V. N-terminal fusion of the N-terminal domain of bacterial enzyme I facilitates recombinant expression and purification of the human RNA demethylases FTO and Alkbh5. Protein Expr Purif 2019; 167:105540. [PMID: 31740367 DOI: 10.1016/j.pep.2019.105540] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 11/14/2019] [Accepted: 11/14/2019] [Indexed: 01/20/2023]
Abstract
Various fusion tags are commonly employed to increase the heterologous expression and solubility of aggregation-prone proteins within Escherichia coli. Herein, we present a protocol for efficient recombinant expression and purification of the human RNA demethylases Alkbh5 and FTO. Our method incorporates a novel fusion tag (the N-terminal domain of bacterial enzyme I, EIN) that dramatically increases the solubility of its fusion partner and is promptly removed upon digestion with a protease. The presented protocol allows for the production of mg amounts of Alkbh5 and FTO in 1L of both rich and minimal media. We developed a liquid chromatography-mass spectrometry (LC-MS)-based assay to confirm that both proteins are enzymatically active. Furthermore, the LC-MS method developed here is applicable to other members of the AlkB family of Fe(II)/α-ketoglutarate-dependent dioxygenases. The superior protein yield, afforded by our expression and purification method, will facilitate biochemical investigations into the biological function of the human RNA demethylases and endorse employment of EIN as a broadly applicable fusion tag for recombinant expression projects.
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Affiliation(s)
| | - Jeffrey A Purslow
- Department of Chemistry, 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
| | - Vincenzo Venditti
- Department of Chemistry, Iowa State University, Ames, IA, 50011, USA; Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA.
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7
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Affiliation(s)
- Hanna S. Loving
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, United States
| | - Eric S. Underbakke
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, United States
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8
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Masson GR, Burke JE, Ahn NG, Anand GS, Borchers C, Brier S, Bou-Assaf GM, Engen JR, Englander SW, Faber J, Garlish R, Griffin PR, Gross ML, Guttman M, Hamuro Y, Heck AJR, Houde D, Iacob RE, Jørgensen TJD, Kaltashov IA, Klinman JP, Konermann L, Man P, Mayne L, Pascal BD, Reichmann D, Skehel M, Snijder J, Strutzenberg TS, Underbakke ES, Wagner C, Wales TE, Walters BT, Weis DD, Wilson DJ, Wintrode PL, Zhang Z, Zheng J, Schriemer DC, Rand KD. Recommendations for performing, interpreting and reporting hydrogen deuterium exchange mass spectrometry (HDX-MS) experiments. Nat Methods 2019; 16:595-602. [PMID: 31249422 PMCID: PMC6614034 DOI: 10.1038/s41592-019-0459-y] [Citation(s) in RCA: 375] [Impact Index Per Article: 75.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 05/23/2019] [Indexed: 12/20/2022]
Abstract
Hydrogen deuterium exchange mass spectrometry (HDX-MS) is a powerful biophysical technique being increasingly applied to a wide variety of problems. As the HDX-MS community continues to grow, adoption of best practices in data collection, analysis, presentation and interpretation will greatly enhance the accessibility of this technique to nonspecialists. Here we provide recommendations arising from community discussions emerging out of the first International Conference on Hydrogen-Exchange Mass Spectrometry (IC-HDX; 2017). It is meant to represent both a consensus viewpoint and an opportunity to stimulate further additions and refinements as the field advances.
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Affiliation(s)
| | - John E Burke
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada.
| | - Natalie G Ahn
- Department of Biochemistry, University of Colorado, Boulder, CO, USA
| | - Ganesh S Anand
- Department of Biological Science, National University of Singapore, Singapore, Singapore
| | - Christoph Borchers
- Genome BC Proteomics Centre, University of Victoria, Victoria, BC, Canada
| | - Sébastien Brier
- Institut Pasteur, Chemistry and Structural Biology Department, Paris, France
| | | | - John R Engen
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, USA
| | - S Walter Englander
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, USA
| | | | | | - Patrick R Griffin
- Department of Integrative Structural and Computational Biology, Scripps Florida, The Scripps Research Institute, Jupiter, FL, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA
| | - Miklos Guttman
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Seattle, WA, USA
| | - Yoshitomo Hamuro
- Johnson & Johnson Pharmaeutical Research and Development, Jersey City, NJ, USA
| | - Albert J R Heck
- Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, the Netherlands
| | | | - Roxana E Iacob
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, USA
| | - Thomas J D Jørgensen
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej, Odense, Denmark
| | - Igor A Kaltashov
- Department of Chemistry, University of Massachusetts-Amherst, Amherst, MA, USA
| | - Judith P Klinman
- Department of Chemistry, University of California, Berkeley, Berkeley, CA, USA
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, ON, Canada
| | - Petr Man
- Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Leland Mayne
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA, USA
| | - Bruce D Pascal
- Department of Molecular Medicine, The Scripps Research Institute, Jupiter, FL, USA
| | - Dana Reichmann
- Department of Biological Chemistry, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Mark Skehel
- MRC Laboratory of Molecular Biology, Cambridge, UK
| | - Joost Snijder
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Seattle, WA, USA
| | - Timothy S Strutzenberg
- Department of Integrative Structural and Computational Biology, Scripps Florida, The Scripps Research Institute, Jupiter, FL, USA
| | - Eric S Underbakke
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA, USA
| | | | - Thomas E Wales
- Department of Chemistry and Chemical Biology, Northeastern University, Boston, MA, USA
| | - Benjamin T Walters
- Department of Early Stage Pharmaceutical Development, Genentech, Inc., South San Francisco, CA, USA
| | - David D Weis
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS, USA
| | - Derek J Wilson
- Department of Chemistry, York University, Toronto, ON, Canada
| | - Patrick L Wintrode
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, MD, USA
| | | | - Jie Zheng
- Department of Integrative Structural and Computational Biology, Scripps Florida, The Scripps Research Institute, Jupiter, FL, USA
| | - David C Schriemer
- Department of Biochemistry & Molecular Biology, University of Calgary, Calgary, AB, Canada.
| | - Kasper D Rand
- Department of Pharmacy, University of Copenhagen, Copenhagen, Denmark.
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9
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McClure NA, Loving HS, Underbakke ES. Mapping regulatory interactions in Proline‐rich tyrosine kinase 2 by cross‐linking. FASEB J 2019. [DOI: 10.1096/fasebj.2019.33.1_supplement.478.8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Natalie A. McClure
- Roy J. Carver Dept. of Biochemistry Biophysics and Molecular BiologyIowa State UniversityAmesIA
| | - Hanna S. Loving
- Roy J. Carver Dept. of Biochemistry Biophysics and Molecular BiologyIowa State UniversityAmesIA
| | - Eric S. Underbakke
- Roy J. Carver Dept. of Biochemistry Biophysics and Molecular BiologyIowa State UniversityAmesIA
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10
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Hanson QM, Carley JR, Gilbreath TJ, Smith BC, Underbakke ES. Calmodulin-induced Conformational Control and Allostery Underlying Neuronal Nitric Oxide Synthase Activation. J Mol Biol 2018; 430:935-947. [PMID: 29458127 DOI: 10.1016/j.jmb.2018.02.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Revised: 02/07/2018] [Accepted: 02/07/2018] [Indexed: 10/18/2022]
Abstract
Nitric oxide synthase (NOS) is the primary generator of nitric oxide signals controlling diverse physiological processes such as neurotransmission and vasodilation. NOS activation is contingent on Ca2+/calmodulin binding at a linker between its oxygenase and reductase domains to induce large conformational changes that orchestrate inter-domain electron transfer. However, the structural dynamics underlying activation of full-length NOS remain ambiguous. Employing hydrogen-deuterium exchange mass spectrometry, we reveal mechanisms underlying neuronal NOS activation by calmodulin and regulation by phosphorylation. We demonstrate that calmodulin binding orders the junction between reductase and oxygenase domains, exposes the FMN subdomain, and elicits a more dynamic oxygenase active site. Furthermore, we demonstrate that phosphorylation partially mimics calmodulin activation to modulate neuronal NOS activity via long-range allostery. Calmodulin binding and phosphorylation ultimately promote a more dynamic holoenzyme while coordinating inter-domain communication and electron transfer.
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Affiliation(s)
- Quinlin M Hanson
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Jeffrey R Carley
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Tyler J Gilbreath
- Roy J. Carver Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
| | - Brian C Smith
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, 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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11
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Underbakke ES, Iavarone AT, Chalmers MJ, Pascal BD, Novick S, Griffin PR, Marletta MA. Nitric oxide-induced conformational changes in soluble guanylate cyclase. Structure 2014; 22:602-11. [PMID: 24560804 DOI: 10.1016/j.str.2014.01.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2013] [Revised: 01/07/2014] [Accepted: 01/13/2014] [Indexed: 01/24/2023]
Abstract
Soluble guanylate cyclase (sGC) is the primary mediator of nitric oxide (NO) signaling. NO binds the sGC heme cofactor stimulating synthesis of the second messenger cyclic-GMP (cGMP). As the central hub of NO/cGMP signaling pathways, sGC is important in diverse physiological processes such as vasodilation and neurotransmission. Nevertheless, the mechanisms underlying NO-induced cyclase activation in sGC remain unclear. Here, hydrogen/deuterium exchange mass spectrometry (HDX-MS) was employed to probe the NO-induced conformational changes of sGC. HDX-MS revealed NO-induced effects in several discrete regions. NO binding to the heme-NO/O2-binding (H-NOX) domain perturbs a signaling surface implicated in Per/Arnt/Sim (PAS) domain interactions. Furthermore, NO elicits striking conformational changes in the junction between the PAS and helical domains that propagate as perturbations throughout the adjoining helices. Ultimately, NO binding stimulates the catalytic domain by contracting the active site pocket. Together, these conformational changes delineate an allosteric pathway linking NO binding to activation of the catalytic domain.
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Affiliation(s)
- Eric S Underbakke
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA
| | - Anthony T Iavarone
- Department of Chemistry and California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Michael J Chalmers
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Bruce D Pascal
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Scott Novick
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Patrick R Griffin
- Department of Molecular Therapeutics, The Scripps Research Institute, Jupiter, FL 33458, USA
| | - Michael A Marletta
- Department of Chemistry, The Scripps Research Institute, La Jolla, CA 92037, USA.
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12
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Fernhoff NB, Derbyshire ER, Underbakke ES, Marletta MA. Heme-assisted S-nitrosation desensitizes ferric soluble guanylate cyclase to nitric oxide. J Biol Chem 2012; 287:43053-62. [PMID: 23093402 DOI: 10.1074/jbc.m112.393892] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Nitric oxide (NO) signaling regulates key processes in cardiovascular physiology, specifically vasodilation, platelet aggregation, and leukocyte rolling. Soluble guanylate cyclase (sGC), the mammalian NO sensor, transduces an NO signal into the classical second messenger cyclic GMP (cGMP). NO binds to the ferrous (Fe(2+)) oxidation state of the sGC heme cofactor and stimulates formation of cGMP several hundred-fold. Oxidation of the sGC heme to the ferric (Fe(3+)) state desensitizes the enzyme to NO. The heme-oxidized state of sGC has emerged as a potential therapeutic target in the treatment of cardiovascular disease. Here, we investigate the molecular mechanism of NO desensitization and find that sGC undergoes a reductive nitrosylation reaction that is coupled to the S-nitrosation of sGC cysteines. We further characterize the kinetics of NO desensitization and find that heme-assisted nitrosothiol formation of β1Cys-78 and β1Cys-122 causes the NO desensitization of ferric sGC. Finally, we provide evidence that the mechanism of reductive nitrosylation is gated by a conformational change of the protein. These results yield insights into the function and dysfunction of sGC in cardiovascular disease.
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Affiliation(s)
- Nathaniel B Fernhoff
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
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13
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Marletta MA, Underbakke ES, Fernhoff NB. Molecular aspects of sGC regulation. BMC Pharmacol 2011. [PMCID: PMC3363167 DOI: 10.1186/1471-2210-11-s1-o10] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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14
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Underbakke ES, Zhu Y, Kiessling LL. Protein footprinting in a complex milieu: identifying the interaction surfaces of the chemotaxis adaptor protein CheW. J Mol Biol 2011; 409:483-95. [PMID: 21463637 PMCID: PMC3179904 DOI: 10.1016/j.jmb.2011.03.040] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2011] [Revised: 03/16/2011] [Accepted: 03/17/2011] [Indexed: 10/18/2022]
Abstract
Characterizing protein-protein interactions in a biologically relevant context is important for understanding the mechanisms of signal transduction. Most signal transduction systems are membrane associated and consist of large multiprotein complexes that undergo rapid reorganization--circumstances that present challenges to traditional structure determination methods. To study protein-protein interactions in a biologically relevant complex milieu, we employed a protein footprinting strategy based on isotope-coded affinity tag (ICAT) reagents. ICAT reagents are valuable tools for proteomics. Here, we show their utility in an alternative application--they are ideal for protein footprinting in complex backgrounds because the affinity tag moiety allows for enrichment of alkylated species prior to analysis. We employed a water-soluble ICAT reagent to monitor cysteine accessibility and thereby to identify residues involved in two different protein-protein interactions in the Escherichia coli chemotaxis signaling system. The chemotaxis system is an archetypal transmembrane signaling pathway in which a complex protein superstructure underlies sophisticated sensory performance. The formation of this superstructure depends on the adaptor protein CheW, which mediates a functionally important bridging interaction between transmembrane receptors and histidine kinase. ICAT footprinting was used to map the surfaces of CheW that interact with the large multidomain histidine kinase CheA, as well as with the transmembrane chemoreceptor Tsr in native E. coli membranes. By leveraging the affinity tag, we successfully identified CheW surfaces responsible for CheA-Tsr interaction. The proximity of the CheA and Tsr binding sites on CheW suggests the formation of a composite CheW-Tsr surface for the recruitment of the signaling kinase to the chemoreceptor complex.
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Affiliation(s)
- Eric S Underbakke
- Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53706, USA
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15
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Affiliation(s)
- Eric S Underbakke
- Department of Biochemistry, University of Wisconsin, Madison, WI, USA
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16
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Affiliation(s)
- Eric S Underbakke
- Departments of Chemistry and Biochemistry, University of Wisconsin, Madison, Madison, WI 53706 (USA), Fax: (+1) 608-265-0764
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Abstract
We report a general method for the solid-phase synthesis of polymers via the ring-opening metathesis polymerization (ROMP). The method involves polymerization in solution to form a block copolymer, immobilization of the polymer via reaction of one block with a resin-bound functional group, modification of the other block, and liberation of the polymer from the resin. We demonstrated the utility of this approach by generating a block copolymer with an N-hydroxysuccinimidyl ester-substituted block (for on-resin functionalization) and a maleimide-substituted block (for conjugation to the resin). We showed that the Diels-Alder reaction can be employed to immobilize the polymers and that amines of diverse structure can be used to modify the resin-bound polymers. The reversibility of the furan-maleimide Diels-Alder adduct was exploited to liberate the polymer from the support. Specifically, treatment of the resin with cyclopentadiene resulted in complete polymer release. The resulting polymers are functional: they were as potent in assays with the lectin concanavalin A as polymers generated by traditional solution routes. We anticipate that this method can be used for the rapid synthesis of diverse polymers via ROMP.
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Affiliation(s)
- Jason K Pontrello
- Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA
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