1
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Zhang L, Wang Y, Homan KT, Gaudette SM, McCluskey AJ, Chan Y, Murphy J, Abdalla M, Nelson CM, Sun VZ, Erickson JE, Knight HL, Clabbers A, Sterman AJS, Mitra S. Imaging the Alternatively Spliced D Domain of Tenascin C in a Preclinical Model of Inflammatory Bowel Disease. Mol Imaging Biol 2023; 25:314-323. [PMID: 35906512 PMCID: PMC10006278 DOI: 10.1007/s11307-022-01758-6] [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: 04/20/2022] [Revised: 07/11/2022] [Accepted: 07/12/2022] [Indexed: 11/28/2022]
Abstract
PURPOSE To image colon-expressed alternatively spliced D domain of tenascin C in preclinical colitis models using near infrared (NIR)-labeled targeted molecular imaging agents. PROCEDURES A human IgG1 with nanomolar binding affinity specific to the alternatively spliced D domain of tenascin C was generated. Immunohistochemistry identified disease-specific expression of this extracellular matrix protein in the colon of mice given dextran sulfate sodium in the drinking water. The antibody reagent was labeled with the NIR fluorophore IRDye 800CW via amine chemistry and intravenously dosed to evaluate in vivo targeting specificity. Increasing doses of imaging agent were given to estimate the saturating dose. RESULTS The NIR-labeled proteins successfully targeted colonic lesions in a murine model of colitis. Co-administration of a molar excess competing unlabeled dose reduced normalized uptake in diseased colon by > 70%. Near infrared ex vivo images of colon resected from diseased animals showed saturation at doses exceeding 1 nmol and was confirmed with additional quantitative ex vivo biodistribution. Cellular-level specificity and protein stability were assessed via microscopy. CONCLUSIONS Our imaging data suggest the alternatively spliced D domain of tenascin C is a promising target for delivery-based applications in inflammatory bowel diseases.
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Affiliation(s)
- Liang Zhang
- AbbVie Bioresearch Center, 100 Research Dr, Worcester, MA, 01605, USA.
| | - Yuzhen Wang
- AbbVie Bioresearch Center, 100 Research Dr, Worcester, MA, 01605, USA
| | | | - Stephanie M Gaudette
- Worcester Technical High School, 1 Officer Manny Familia Wy, Worcester, MA, 01605, USA
| | | | - Ying Chan
- AbbVie Bioresearch Center, 100 Research Dr, Worcester, MA, 01605, USA
| | - Joanne Murphy
- AbbVie Bioresearch Center, 100 Research Dr, Worcester, MA, 01605, USA
| | - Mary Abdalla
- AbbVie Bioresearch Center, 100 Research Dr, Worcester, MA, 01605, USA
| | | | - Victor Z Sun
- AbbVie Bioresearch Center, 100 Research Dr, Worcester, MA, 01605, USA
| | - Jamie E Erickson
- AbbVie Bioresearch Center, 100 Research Dr, Worcester, MA, 01605, USA
| | - Heather L Knight
- AbbVie Bioresearch Center, 100 Research Dr, Worcester, MA, 01605, USA
| | - Anca Clabbers
- AbbVie Bioresearch Center, 100 Research Dr, Worcester, MA, 01605, USA
| | | | - Soumya Mitra
- AbbVie Bioresearch Center, 100 Research Dr, Worcester, MA, 01605, USA
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2
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Waldschmidt HV, Homan KT, Cato MC, Cruz-Rodríguez O, Cannavo A, Wilson MW, Song J, Cheung JY, Koch WJ, Tesmer JJG, Larsen SD. Correction to “Structure-Based Design of Highly Selective and Potent G Protein-Coupled Receptor Kinase 2 Inhibitors Based on Paroxetine”. J Med Chem 2019; 62:5920. [DOI: 10.1021/acs.jmedchem.9b00844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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3
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Waldschmidt HV, Homan KT, Cato MC, Cruz-Rodríguez O, Cannavo A, Wilson MW, Song J, Cheung JY, Koch WJ, Tesmer JJG, Larsen SD. Structure-Based Design of Highly Selective and Potent G Protein-Coupled Receptor Kinase 2 Inhibitors Based on Paroxetine. J Med Chem 2017; 60:3052-3069. [PMID: 28323425 DOI: 10.1021/acs.jmedchem.7b00112] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In heart failure, the β-adrenergic receptors (βARs) become desensitized and uncoupled from heterotrimeric G proteins. This process is initiated by G protein-coupled receptor kinases (GRKs), some of which are upregulated in the failing heart, making them desirable therapeutic targets. The selective serotonin reuptake inhibitor, paroxetine, was previously identified as a GRK2 inhibitor. Utilizing a structure-based drug design approach, we modified paroxetine to generate a small compound library. Included in this series is a highly potent and selective GRK2 inhibitor, 14as, with an IC50 of 30 nM against GRK2 and greater than 230-fold selectivity over other GRKs and kinases. Furthermore, 14as showed a 100-fold improvement in cardiomyocyte contractility assays over paroxetine and a plasma concentration higher than its IC50 for over 7 h. Three of these inhibitors, including 14as, were additionally crystallized in complex with GRK2 to give insights into the structural determinants of potency and selectivity of these inhibitors.
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Affiliation(s)
- Helen V Waldschmidt
- Department of Medicinal Chemistry, College of Pharmacy, ‡Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, §Ph.D. Program in Chemical Biology, ⊥Vahlteich Medicinal Chemistry Core, University of Michigan , Ann Arbor, Michigan 48109, United States.,Center for Translational Medicine, Temple University , Philadelphia, Pennsylvania 19140, United States
| | - Kristoff T Homan
- Department of Medicinal Chemistry, College of Pharmacy, ‡Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, §Ph.D. Program in Chemical Biology, ⊥Vahlteich Medicinal Chemistry Core, University of Michigan , Ann Arbor, Michigan 48109, United States.,Center for Translational Medicine, Temple University , Philadelphia, Pennsylvania 19140, United States
| | - Marilyn C Cato
- Department of Medicinal Chemistry, College of Pharmacy, ‡Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, §Ph.D. Program in Chemical Biology, ⊥Vahlteich Medicinal Chemistry Core, University of Michigan , Ann Arbor, Michigan 48109, United States.,Center for Translational Medicine, Temple University , Philadelphia, Pennsylvania 19140, United States
| | - Osvaldo Cruz-Rodríguez
- Department of Medicinal Chemistry, College of Pharmacy, ‡Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, §Ph.D. Program in Chemical Biology, ⊥Vahlteich Medicinal Chemistry Core, University of Michigan , Ann Arbor, Michigan 48109, United States.,Center for Translational Medicine, Temple University , Philadelphia, Pennsylvania 19140, United States
| | - Alessandro Cannavo
- Department of Medicinal Chemistry, College of Pharmacy, ‡Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, §Ph.D. Program in Chemical Biology, ⊥Vahlteich Medicinal Chemistry Core, University of Michigan , Ann Arbor, Michigan 48109, United States.,Center for Translational Medicine, Temple University , Philadelphia, Pennsylvania 19140, United States
| | - Michael W Wilson
- Department of Medicinal Chemistry, College of Pharmacy, ‡Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, §Ph.D. Program in Chemical Biology, ⊥Vahlteich Medicinal Chemistry Core, University of Michigan , Ann Arbor, Michigan 48109, United States.,Center for Translational Medicine, Temple University , Philadelphia, Pennsylvania 19140, United States
| | - Jianliang Song
- Department of Medicinal Chemistry, College of Pharmacy, ‡Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, §Ph.D. Program in Chemical Biology, ⊥Vahlteich Medicinal Chemistry Core, University of Michigan , Ann Arbor, Michigan 48109, United States.,Center for Translational Medicine, Temple University , Philadelphia, Pennsylvania 19140, United States
| | - Joseph Y Cheung
- Department of Medicinal Chemistry, College of Pharmacy, ‡Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, §Ph.D. Program in Chemical Biology, ⊥Vahlteich Medicinal Chemistry Core, University of Michigan , Ann Arbor, Michigan 48109, United States.,Center for Translational Medicine, Temple University , Philadelphia, Pennsylvania 19140, United States
| | - Walter J Koch
- Department of Medicinal Chemistry, College of Pharmacy, ‡Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, §Ph.D. Program in Chemical Biology, ⊥Vahlteich Medicinal Chemistry Core, University of Michigan , Ann Arbor, Michigan 48109, United States.,Center for Translational Medicine, Temple University , Philadelphia, Pennsylvania 19140, United States
| | - John J G Tesmer
- Department of Medicinal Chemistry, College of Pharmacy, ‡Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, §Ph.D. Program in Chemical Biology, ⊥Vahlteich Medicinal Chemistry Core, University of Michigan , Ann Arbor, Michigan 48109, United States.,Center for Translational Medicine, Temple University , Philadelphia, Pennsylvania 19140, United States
| | - Scott D Larsen
- Department of Medicinal Chemistry, College of Pharmacy, ‡Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, §Ph.D. Program in Chemical Biology, ⊥Vahlteich Medicinal Chemistry Core, University of Michigan , Ann Arbor, Michigan 48109, United States.,Center for Translational Medicine, Temple University , Philadelphia, Pennsylvania 19140, United States
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4
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Yang P, Homan KT, Li Y, Cruz-Rodríguez O, Tesmer JJG, Chen Z. Effect of Lipid Composition on the Membrane Orientation of the G Protein-Coupled Receptor Kinase 2-Gβ1γ2 Complex. Biochemistry 2016; 55:2841-8. [PMID: 27088923 DOI: 10.1021/acs.biochem.6b00354] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Interactions between proteins and cell membranes are critical for biological processes such as transmembrane signaling, and specific components of the membrane may play roles in helping to organize or mandate particular conformations of both integral and peripheral membrane proteins. One example of a signaling enzyme whose function is dependent on membrane binding and whose activity is affected by specific lipid components is G protein-coupled receptor (GPCR) kinase 2 (GRK2). Efficient GRK2-mediated phosphorylation of activated GPCRs is dependent not only on its recruitment to the membrane by heterotrimeric Gβγ subunits but also on the presence of highly negatively charged lipids, in particular phosphatidylinositol 4',5'-bisphosphate (PIP2). We hypothesized that PIP2 may favor a distinct orientation of the GRK2-Gβγ complex on the membrane that is more optimal for function. In this study, we compared the possible orientations of the GRK2-Gβγ complex and Gβγ alone on model cell membranes prepared with various anionic phospholipids as deduced from sum frequency generation vibrational and attenuated total reflectance Fourier transform infrared spectroscopic methods. Our results indicate that PIP2 affects the membrane orientation of the GRK2-Gβ1γ2 complex but not that of complexes formed with anionic phospholipid binding deficient mutations in the GRK2 pleckstrin homology (PH) domain. Gβ1γ2 exhibits a similar orientation on the lipid bilayer regardless of its lipid composition. The PIP2-induced orientation of the GRK2-Gβ1γ2 complex is therefore most likely caused by specific interactions between PIP2 and the GRK2 PH domain. Thus, PIP2 not only helps recruit GRK2 to the membrane but also "fine tunes" the orientation of the GRK2-Gβγ complex so that it is better positioned to phosphorylate activated GPCRs.
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Affiliation(s)
- Pei Yang
- Department of Chemistry, University of Michigan , 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Kristoff T Homan
- Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Yaoxin Li
- Department of Chemistry, University of Michigan , 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Osvaldo Cruz-Rodríguez
- Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, University of Michigan , Ann Arbor, Michigan 48109, United States.,Ph.D. Program in Chemical Biology, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - John J G Tesmer
- Departments of Pharmacology and Biological Chemistry, Life Sciences Institute, University of Michigan , Ann Arbor, Michigan 48109, United States
| | - Zhan Chen
- Department of Chemistry, University of Michigan , 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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5
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Waldschmidt HV, Homan KT, Cruz-Rodríguez O, Cato MC, Waninger-Saroni J, Larimore KL, Cannavo A, Song J, Cheung JY, Koch WJ, Tesmer JJG, Larsen SD, Larsen SD. Structure-Based Design, Synthesis, and Biological Evaluation of Highly Selective and Potent G Protein-Coupled Receptor Kinase 2 Inhibitors. J Med Chem 2016; 59:3793-807. [PMID: 27050625 PMCID: PMC4890168 DOI: 10.1021/acs.jmedchem.5b02000] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
G protein-coupled receptors (GPCRs) are central to many physiological processes. Regulation of this superfamily of receptors is controlled by GPCR kinases (GRKs), some of which have been implicated in heart failure. GSK180736A, developed as a Rho-associated coiled-coil kinase 1 (ROCK1) inhibitor, was identified as an inhibitor of GRK2 and co-crystallized in the active site. Guided by its binding pose overlaid with the binding pose of a known potent GRK2 inhibitor, Takeda103A, a library of hybrid inhibitors was developed. This campaign produced several compounds possessing high potency and selectivity for GRK2 over other GRK subfamilies, PKA, and ROCK1. The most selective compound, 12n (CCG-224406), had an IC50 for GRK2 of 130 nM, >700-fold selectivity over other GRK subfamilies, and no detectable inhibition of ROCK1. Four of the new inhibitors were crystallized with GRK2 to give molecular insights into the binding and kinase selectivity of this class of inhibitors.
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Affiliation(s)
- Helen V. Waldschmidt
- Vahlteich Medicinal Chemistry Core, College of Pharmacy, University of Michigan, Ann Arbor, Michigan, 48109,Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109,Departments of Medicinal Chemistry, Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan, 48109
| | - Kristoff T. Homan
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109,Departments of Medicinal Chemistry, Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan, 48109
| | - Osvaldo Cruz-Rodríguez
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109,PhD Program in Chemical Biology, University of Michigan, Ann Arbor, Michigan, 48109,Departments of Medicinal Chemistry, Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan, 48109
| | - Marilyn C. Cato
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109,Departments of Medicinal Chemistry, Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan, 48109
| | - Jessica Waninger-Saroni
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109,Departments of Medicinal Chemistry, Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan, 48109,Medical Scientist Training Program, University of Michigan, Ann Arbor, Michigan, 48109
| | - Kelly L. Larimore
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109,Departments of Medicinal Chemistry, Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan, 48109
| | - Alessandro Cannavo
- Center for Translational Medicine, Temple University, Philadelphia, Pennsylvania, 19140
| | - Jianliang Song
- Center for Translational Medicine, Temple University, Philadelphia, Pennsylvania, 19140
| | - Joseph Y. Cheung
- Center for Translational Medicine, Temple University, Philadelphia, Pennsylvania, 19140
| | - Walter J. Koch
- Center for Translational Medicine, Temple University, Philadelphia, Pennsylvania, 19140
| | - John J. G. Tesmer
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109,Departments of Medicinal Chemistry, Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan, 48109
| | - Scott D. Larsen
- Vahlteich Medicinal Chemistry Core, College of Pharmacy, University of Michigan, Ann Arbor, Michigan, 48109,Departments of Medicinal Chemistry, Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan, 48109,Corresponding Author: Scott D. Larsen, , (734) 615 - 0454
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6
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Inagaki S, Ghirlando R, Vishnivetskiy SA, Homan KT, White JF, Tesmer JJG, Gurevich VV, Grisshammer R. G Protein-Coupled Receptor Kinase 2 (GRK2) and 5 (GRK5) Exhibit Selective Phosphorylation of the Neurotensin Receptor in Vitro. Biochemistry 2015; 54:4320-9. [PMID: 26120872 PMCID: PMC4512254 DOI: 10.1021/acs.biochem.5b00285] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [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] [Indexed: 12/24/2022]
Abstract
![]()
G protein-coupled
receptor kinases (GRKs) play an important role
in the desensitization of G protein-mediated signaling of G protein-coupled
receptors (GPCRs). The level of interest in mapping their phosphorylation
sites has increased because recent studies suggest that the differential
pattern of receptor phosphorylation has distinct biological consequences. In vitro phosphorylation experiments using well-controlled
systems are useful for deciphering the complexity of these physiological
reactions and understanding the targeted event. Here, we report on
the phosphorylation of the class A GPCR neurotensin receptor 1 (NTSR1)
by GRKs under defined experimental conditions afforded by nanodisc
technology. Phosphorylation of NTSR1 by GRK2 was agonist-dependent,
whereas phosphorylation by GRK5 occurred in an activation-independent
manner. In addition, the negatively charged lipids in the immediate
vicinity of NTSR1 directly affect phosphorylation by GRKs. Identification
of phosphorylation sites in agonist-activated NTSR1 revealed that
GRK2 and GRK5 target different residues located on the intracellular
receptor elements. GRK2 phosphorylates only the C-terminal Ser residues,
whereas GRK5 phosphorylates Ser and Thr residues located in intracellular
loop 3 and the C-terminus. Interestingly, phosphorylation assays using
a series of NTSR1 mutants show that GRK2 does not require acidic residues
upstream of the phospho-acceptors for site-specific phosphorylation,
in contrast to the β2-adrenergic and μ-opioid
receptors. Differential phosphorylation of GPCRs by GRKs is thought
to encode a particular signaling outcome, and our in vitro study revealed NTSR1 differential phosphorylation by GRK2 and GRK5.
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Affiliation(s)
- Sayaka Inagaki
- †Membrane Protein Structure Function Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland 20852, United States
| | - Rodolfo Ghirlando
- ‡Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services, Bethesda, Maryland 20892, United States
| | - Sergey A Vishnivetskiy
- §Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Kristoff T Homan
- ∥Departments of Pharmacology and Biological Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jim F White
- †Membrane Protein Structure Function Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland 20852, United States
| | - John J G Tesmer
- ∥Departments of Pharmacology and Biological Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Vsevolod V Gurevich
- §Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, United States
| | - Reinhard Grisshammer
- †Membrane Protein Structure Function Unit, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Department of Health and Human Services, Rockville, Maryland 20852, United States
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7
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Homan KT, Waldschmidt HV, Glukhova A, Cannavo A, Song J, Cheung JY, Koch WJ, Larsen SD, Tesmer JJG. Crystal Structure of G Protein-coupled Receptor Kinase 5 in Complex with a Rationally Designed Inhibitor. J Biol Chem 2015; 290:20649-20659. [PMID: 26032411 DOI: 10.1074/jbc.m115.647370] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [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: 02/24/2015] [Indexed: 11/06/2022] Open
Abstract
G protein-coupled receptor kinases (GRKs) regulate cell signaling by initiating the desensitization of active G protein-coupled receptors. The two most widely expressed GRKs (GRK2 and GRK5) play a role in cardiovascular disease and thus represent important targets for the development of novel therapeutic drugs. In the course of a GRK2 structure-based drug design campaign, one inhibitor (CCG215022) exhibited nanomolar IC50 values against both GRK2 and GRK5 and good selectivity against other closely related kinases such as GRK1 and PKA. Treatment of murine cardiomyocytes with CCG215022 resulted in significantly increased contractility at 20-fold lower concentrations than paroxetine, an inhibitor with more modest selectivity for GRK2. A 2.4 Å crystal structure of the GRK5·CCG215022 complex was determined and revealed that the inhibitor binds in the active site similarly to its parent compound GSK180736A. As designed, its 2-pyridylmethyl amide side chain occupies the hydrophobic subsite of the active site where it forms three additional hydrogen bonds, including one with the catalytic lysine. The overall conformation of the GRK5 kinase domain is similar to that of a previously determined structure of GRK6 in what is proposed to be its active state, but the C-terminal region of the enzyme adopts a distinct conformation. The kinetic properties of site-directed mutants in this region are consistent with the hypothesis that this novel C-terminal structure is representative of the membrane-bound conformation of the enzyme.
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Affiliation(s)
- Kristoff T Homan
- Life Sciences Institute and the Departments of Pharmacology and Biological Sciences, University of Michigan, Ann Arbor, Michigan 48109
| | - Helen V Waldschmidt
- Vahlteich Medicinal Chemistry Core and the Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109
| | - Alisa Glukhova
- Life Sciences Institute and the Departments of Pharmacology and Biological Sciences, University of Michigan, Ann Arbor, Michigan 48109
| | - Alessandro Cannavo
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
| | - Jianliang Song
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
| | - Joseph Y Cheung
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
| | - Walter J Koch
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
| | - Scott D Larsen
- Vahlteich Medicinal Chemistry Core and the Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan 48109
| | - John J G Tesmer
- Life Sciences Institute and the Departments of Pharmacology and Biological Sciences, University of Michigan, Ann Arbor, Michigan 48109.
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8
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Azevedo AW, Doan T, Moaven H, Sokal I, Baameur F, Vishnivetskiy SA, Homan KT, Tesmer JJG, Gurevich VV, Chen J, Rieke F. C-terminal threonines and serines play distinct roles in the desensitization of rhodopsin, a G protein-coupled receptor. eLife 2015; 4. [PMID: 25910054 PMCID: PMC4438306 DOI: 10.7554/elife.05981] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Accepted: 04/23/2015] [Indexed: 12/31/2022] Open
Abstract
Rod photoreceptors generate measurable responses to single-photon activation of individual molecules of the G protein-coupled receptor (GPCR), rhodopsin. Timely rhodopsin desensitization depends on phosphorylation and arrestin binding, which quenches G protein activation. Rhodopsin phosphorylation has been measured biochemically at C-terminal serine residues, suggesting that these residues are critical for producing fast, low-noise responses. The role of native threonine residues is unclear. We compared single-photon responses from rhodopsin lacking native serine or threonine phosphorylation sites. Contrary to expectation, serine-only rhodopsin generated prolonged step-like single-photon responses that terminated abruptly and randomly, whereas threonine-only rhodopsin generated responses that were only modestly slower than normal. We show that the step-like responses of serine-only rhodopsin reflect slow and stochastic arrestin binding. Thus, threonine sites play a privileged role in promoting timely arrestin binding and rhodopsin desensitization. Similar coordination of phosphorylation and arrestin binding may more generally permit tight control of the duration of GPCR activity. DOI:http://dx.doi.org/10.7554/eLife.05981.001 ‘Rod’ cells in the eye enable us to see in starlight. Inside these cells, a protein called rhodopsin is activated by light, which leads to an electrical signal being produced that travels to the brain. The duration of the electrical signal depends on the time it takes for the rhodopsin to be deactivated. Rhodopsin is a member of a large class of receptor proteins known as G protein-coupled receptors that regulate many processes throughout the body. Previous studies have shown that rhodopsin is deactivated by the attachment of phosphate groups to the protein. This allows another protein called arrestin to bind to rhodopsin. The phosphates can be attached to particular amino acids—the building blocks of proteins—at one end of rhodopsin. Three of these are a type of amino acid called serine. Previous work has shown that light increases the speed at which phosphate groups are added to these serines, suggesting that they are important for producing rapid electrical signals. The other three amino acids are of a different type—called threonine—but it is less clear what role they play in deactivating rhodopsin. Here, Azevedo et al. studied mutant forms of rhodopsin that were missing the serines or threonines in mice. The experiments show that loss of the serines only slightly slowed the electrical signals. However, loss of the threonines resulted in much slower electrical signals that ended at random times. This was due to rhodopsin being less able to bind to arrestin. Azevedo et al. propose a new model for how rhodopsin is deactivated. Once light activates the protein, phosphate groups are rapidly added to the serines, which begins to lower the activity of rhodopsin. However, it is the slower addition of phosphates to the threonines that is essential to promote arrestin binding and fully deactivate the protein. Other proteins belonging to the G protein-coupled receptor family also have these serines and threonines, and thus, may be regulated in a similar way. DOI:http://dx.doi.org/10.7554/eLife.05981.002
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Affiliation(s)
- Anthony W Azevedo
- Department of Physiology and Biophysics, University of Washington, Seattle, United States
| | - Thuy Doan
- Department of Ophthalmology, University of Washington, Seattle, United States
| | - Hormoz Moaven
- Departments of Cell & Neurobiology and Ophthalmology, Zilkha Neurogenetic Institute, Keck School of Medicine of University of Southern California, Los Angeles, United States
| | - Iza Sokal
- Department of Physiology and Biophysics, University of Washington, Seattle, United States
| | - Faiza Baameur
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, United States
| | - Sergey A Vishnivetskiy
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, United States
| | - Kristoff T Homan
- Life Sciences Institute, Departments of Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, United States
| | - John J G Tesmer
- Life Sciences Institute, Departments of Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, United States
| | - Vsevolod V Gurevich
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, United States
| | - Jeannie Chen
- Departments of Cell & Neurobiology and Ophthalmology, Zilkha Neurogenetic Institute, Keck School of Medicine of University of Southern California, Los Angeles, United States
| | - Fred Rieke
- Department of Physiology and Biophysics, University of Washington, Seattle, United States
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9
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Li L, Homan KT, Vishnivetskiy SA, Manglik A, Tesmer JJG, Gurevich VV, Gurevich EV. G Protein-coupled Receptor Kinases of the GRK4 Protein Subfamily Phosphorylate Inactive G Protein-coupled Receptors (GPCRs). J Biol Chem 2015; 290:10775-90. [PMID: 25770216 DOI: 10.1074/jbc.m115.644773] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [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: 02/10/2015] [Indexed: 01/14/2023] Open
Abstract
G protein-coupled receptor (GPCR) kinases (GRKs) play a key role in homologous desensitization of GPCRs. It is widely assumed that most GRKs selectively phosphorylate only active GPCRs. Here, we show that although this seems to be the case for the GRK2/3 subfamily, GRK5/6 effectively phosphorylate inactive forms of several GPCRs, including β2-adrenergic and M2 muscarinic receptors, which are commonly used as representative models for GPCRs. Agonist-independent GPCR phosphorylation cannot be explained by constitutive activity of the receptor or membrane association of the GRK, suggesting that it is an inherent ability of GRK5/6. Importantly, phosphorylation of the inactive β2-adrenergic receptor enhanced its interactions with arrestins. Arrestin-3 was able to discriminate between phosphorylation of the same receptor by GRK2 and GRK5, demonstrating preference for the latter. Arrestin recruitment to inactive phosphorylated GPCRs suggests that not only agonist activation but also the complement of GRKs in the cell regulate formation of the arrestin-receptor complex and thereby G protein-independent signaling.
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Affiliation(s)
- Lingyong Li
- From the Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
| | - Kristoff T Homan
- the Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109-2216, and
| | | | - Aashish Manglik
- the Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305
| | - John J G Tesmer
- the Life Sciences Institute, University of Michigan, Ann Arbor, Michigan 48109-2216, and
| | - Vsevolod V Gurevich
- From the Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232
| | - Eugenia V Gurevich
- From the Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232,
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10
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Abstract
Small molecules that inhibit the protein kinase A, G, and C (AGC) family of serine/threonine kinases can exert profound effects on cell homeostasis and thereby regulate fundamental processes such as heart rate, blood pressure, and metabolism, but there is not yet a clinically approved drug in the United States selective for a member of this family. One subfamily of AGC kinases, the G protein-coupled receptor (GPCR) kinases (GRKs), initiates the desensitization of active GPCRs. Of these, GRK2 has been directly implicated in the progression of heart failure. Thus, there is great interest in the identification of GRK2-specific chemical probes that can be further developed into therapeutics. Herein, we compare crystal structures of small molecule inhibitors in complex with GRK2 to those of highly selective compounds in complex with Rho-associated coiled-coil containing kinase 1 (ROCK1), a closely related AGC kinase. This analysis suggests that reduced hydrogen-bond formation with the hinge of the kinase domain, occupation of the hydrophobic subsite, and, consequently, higher buried surface area are key drivers of potency and selectivity among GRK inhibitors.
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Affiliation(s)
- Kristoff T. Homan
- Life Sciences Institute,
Departments of Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - John J. G. Tesmer
- Life Sciences Institute,
Departments of Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
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11
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Homan KT, Larimore KM, Elkins JM, Szklarz M, Knapp S, Tesmer JJG. Identification and structure-function analysis of subfamily selective G protein-coupled receptor kinase inhibitors. ACS Chem Biol 2015; 10:310-9. [PMID: 25238254 PMCID: PMC4301037 DOI: 10.1021/cb5006323] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [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] [Indexed: 12/23/2022]
Abstract
Selective inhibitors of individual subfamilies of G protein-coupled receptor kinases (GRKs) would serve as useful chemical probes as well as leads for therapeutic applications ranging from heart failure to Parkinson's disease. To identify such inhibitors, differential scanning fluorimetry was used to screen a collection of known protein kinase inhibitors that could increase the melting points of the two most ubiquitously expressed GRKs: GRK2 and GRK5. Enzymatic assays on 14 of the most stabilizing hits revealed that three exhibit nanomolar potency of inhibition for individual GRKs, some of which exhibiting orders of magnitude selectivity. Most of the identified compounds can be clustered into two chemical classes: indazole/dihydropyrimidine-containing compounds that are selective for GRK2 and pyrrolopyrimidine-containing compounds that potently inhibit GRK1 and GRK5 but with more modest selectivity. The two most potent inhibitors representing each class, GSK180736A and GSK2163632A, were cocrystallized with GRK2 and GRK1, and their atomic structures were determined to 2.6 and 1.85 Å spacings, respectively. GSK180736A, developed as a Rho-associated, coiled-coil-containing protein kinase inhibitor, binds to GRK2 in a manner analogous to that of paroxetine, whereas GSK2163632A, developed as an insulin-like growth factor 1 receptor inhibitor, occupies a novel region of the GRK active site cleft that could likely be exploited to achieve more selectivity. However, neither compound inhibits GRKs more potently than their initial targets. This data provides the foundation for future efforts to rationally design even more potent and selective GRK inhibitors.
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Affiliation(s)
- Kristoff T. Homan
- Life
Sciences Institute and the Departments of Pharmacology and Biological
Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Kelly M. Larimore
- Life
Sciences Institute and the Departments of Pharmacology and Biological
Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jonathan M. Elkins
- Structural
Genomics Consortium, University of Oxford, Old Road Campus Research Building,
Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
| | - Marta Szklarz
- Structural
Genomics Consortium, University of Oxford, Old Road Campus Research Building,
Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
| | - Stefan Knapp
- Structural
Genomics Consortium, University of Oxford, Old Road Campus Research Building,
Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
- Nuffield
Department of Clinical Medicine, Target Discovery Institute, University of Oxford, NDM Research Building, Roosevelt Drive, Oxford OX3 7FZ, United Kingdom
| | - John J. G. Tesmer
- Life
Sciences Institute and the Departments of Pharmacology and Biological
Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
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12
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Homan KT, Wu E, Wilson MW, Singh P, Larsen SD, Tesmer JJG. Structural and functional analysis of g protein-coupled receptor kinase inhibition by paroxetine and a rationally designed analog. Mol Pharmacol 2013; 85:237-48. [PMID: 24220010 DOI: 10.1124/mol.113.089631] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Recently we identified the serotonin reuptake inhibitor paroxetine as an inhibitor of G protein-coupled receptor kinase 2 (GRK2) that improves cardiac performance in live animals. Paroxetine exhibits up to 50-fold selectivity for GRK2 versus other GRKs. A better understanding of the molecular basis of this selectivity is important for the development of even more selective and potent small molecule therapeutics and chemical genetic probes. We first sought to understand the molecular mechanisms underlying paroxetine selectivity among GRKs. We directly measured the K(D) for paroxetine and assessed its mechanism of inhibition for each of the GRK subfamilies and then determined the atomic structure of its complex with GRK1, the most weakly inhibited GRK tested. Our results suggest that the selectivity of paroxetine for GRK2 largely reflects its lower affinity for adenine nucleotides. Thus, stabilization of off-pathway conformational states unique to GRK2 will likely be key for the development of even more selective inhibitors. Next, we designed a benzolactam derivative of paroxetine that has optimized interactions with the hinge of the GRK2 kinase domain. The crystal structure of this compound in complex with GRK2 confirmed the predicted interactions. Although the benzolactam derivative did not significantly alter potency of inhibition among GRKs, it exhibited 20-fold lower inhibition of serotonin reuptake. However, there was an associated increase in the potency for inhibition of other AGC kinases, suggesting that the unconventional hydrogen bond formed by the benzodioxole ring of paroxetine is better accommodated by GRKs.
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Affiliation(s)
- Kristoff T Homan
- Life Sciences Institute and the Departments of Pharmacology and Biological Sciences (K.T.H., E.W., P.S., J.J.G.T.), and Vahlteich Medicinal Chemistry Core and the Department of Medicinal Chemistry, University of Michigan, Ann Arbor, Michigan (M.W.W., S.D.L.)
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13
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Vishnivetskiy SA, Ostermaier MK, Singhal A, Panneels V, Homan KT, Glukhova A, Sligar SG, Tesmer JJG, Schertler GF, Standfuss J, Gurevich VV. Constitutively active rhodopsin mutants causing night blindness are effectively phosphorylated by GRKs but differ in arrestin-1 binding. Cell Signal 2013; 25:2155-62. [PMID: 23872075 PMCID: PMC3774132 DOI: 10.1016/j.cellsig.2013.07.009] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 07/11/2013] [Indexed: 11/24/2022]
Abstract
The effects of activating mutations associated with night blindness on the stoichiometry of rhodopsin interactions with G protein-coupled receptor kinase 1 (GRK1) and arrestin-1 have not been reported. Here we show that the monomeric form of WT rhodopsin and its constitutively active mutants M257Y, G90D, and T94I, reconstituted into HDL particles are effectively phosphorylated by GRK1, as well as two more ubiquitously expressed subtypes, GRK2 and GRK5. All versions of arrestin-1 tested (WT, pre-activated, and constitutively monomeric mutants) bind to monomeric rhodopsin and show the same selectivity for different functional forms of rhodopsin as in native disc membranes. Rhodopsin phosphorylation by GRK1 and GRK2 promotes arrestin-1 binding to a comparable extent, whereas similar phosphorylation by GRK5 is less effective, suggesting that not all phosphorylation sites on rhodopsin are equivalent in promoting arrestin-1 binding. The binding of WT arrestin-1 to phospho-opsin is comparable to the binding to its preferred target, P-Rh*, suggesting that in photoreceptors arrestin-1 only dissociates after opsin regeneration with 11-cis-retinal, which converts phospho-opsin into inactive phospho-rhodopsin that has lower affinity for arrestin-1. Reduced binding of arrestin-1 to the phospho-opsin form of G90D mutant likely contributes to night blindness caused by this mutation in humans.
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Affiliation(s)
| | - Martin K. Ostermaier
- Laboratory of Biomolecular Research, Paul Scherrer Institut, Villigen 5232, Switzerland
| | - Ankita Singhal
- Laboratory of Biomolecular Research, Paul Scherrer Institut, Villigen 5232, Switzerland
| | - Valerie Panneels
- Laboratory of Biomolecular Research, Paul Scherrer Institut, Villigen 5232, Switzerland
| | - Kristoff T. Homan
- Life Sciences Institute, Departments of Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-2216, USA
| | - Alisa Glukhova
- Life Sciences Institute, Departments of Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-2216, USA
| | - Stephen G. Sligar
- Department of Biochemistry, University of Illinois, Urbana, IL 61801, USA
| | - John J. G. Tesmer
- Life Sciences Institute, Departments of Pharmacology and Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-2216, USA
| | - Gebhard F.X. Schertler
- Laboratory of Biomolecular Research, Paul Scherrer Institut, Villigen 5232, Switzerland
- Department of Biology, ETH Zurich, Zurich, 8093, Switzerland
| | - Joerg Standfuss
- Laboratory of Biomolecular Research, Paul Scherrer Institut, Villigen 5232, Switzerland
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14
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Yang P, Boughton A, Homan KT, Tesmer JJG, Chen Z. Membrane orientation of Gα(i)β(1)γ(2) and Gβ(1)γ(2) determined via combined vibrational spectroscopic studies. J Am Chem Soc 2013; 135:5044-51. [PMID: 23461393 DOI: 10.1021/ja3116026] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The manner in which the heterotrimeric G protein complexes Gβ1γ2 and Gαiβ1γ2 interact with membranes is likely related to their biological function. We combined complementary measurements from sum frequency generation (SFG) vibrational and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy to determine the possible membrane orientations of Gβ1γ2 and the Gαiβ1γ2 heterotrimer more precisely than could be achieved using SFG alone. The most likely orientations of Gβ1γ2 and the Gαiβ1γ2 heterotrimer were both determined to fall within a similar narrow range of twist and tilt angles, suggesting that Gβ1γ2 may bind to Gαi without a significant change in orientation. This "basal" orientation seems to depend primarily on the geranylgeranylated C-terminus of Gγ2 along with basic residues at the N-terminus of Gαi, and suggests that activated G protein-coupled receptors (GPCRs) must reorient G protein heterotrimers at lipid bilayers to catalyze nucleotide exchange. The innovative methodologies developed in this paper can be widely applied to study the membrane orientation of other proteins in situ.
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Affiliation(s)
- Pei Yang
- Department of Chemistry, University of Michiga n, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
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15
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Homan KT, Glukhova A, Tesmer JJG. Regulation of G protein-coupled receptor kinases by phospholipids. Curr Med Chem 2013; 20:39-46. [PMID: 23151001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 09/17/2012] [Accepted: 09/24/2012] [Indexed: 06/01/2023]
Abstract
G protein coupled-receptor (GPCR) kinases (GRKs) initiate the deactivation of GPCRs by phosphorylating their cytoplasmic loops and C-terminal tails. They are regulated not only by allosteric interactions with activated GPCRs, but also by the membrane environment itself. Herein we describe how the various GRKs are recruited to lipid bilayers and, where evident, how specific anionic phospholipids help regulate their activity. Using crystal structures representing each of the three vertebrate GRK subfamilies, we map the lipid binding sites in order to better understand how these enzymes are oriented at the cell surface. This analysis suggests that GRKs bind lipid and active GPCRs in a coordinated manner.
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Affiliation(s)
- K T Homan
- Life Sciences Institute and the Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, USA
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16
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Thal DM, Homan KT, Chen J, Wu EK, Hinkle PM, Huang ZM, Chuprun JK, Song J, Gao E, Cheung JY, Sklar LA, Koch WJ, Tesmer JJ. Paroxetine is a direct inhibitor of g protein-coupled receptor kinase 2 and increases myocardial contractility. ACS Chem Biol 2012; 7:1830-9. [PMID: 22882301 DOI: 10.1021/cb3003013] [Citation(s) in RCA: 144] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
G protein-coupled receptor kinase 2 (GRK2) is a well-established therapeutic target for the treatment of heart failure. Herein we identify the selective serotonin reuptake inhibitor (SSRI) paroxetine as a selective inhibitor of GRK2 activity both in vitro and in living cells. In the crystal structure of the GRK2·paroxetine-Gβγ complex, paroxetine binds in the active site of GRK2 and stabilizes the kinase domain in a novel conformation in which a unique regulatory loop forms part of the ligand binding site. Isolated cardiomyocytes show increased isoproterenol-induced shortening and contraction amplitude in the presence of paroxetine, and pretreatment of mice with paroxetine before isoproterenol significantly increases left ventricular inotropic reserve in vivo with no significant effect on heart rate. Neither is observed in the presence of the SSRI fluoxetine. Our structural and functional results validate a widely available drug as a selective chemical probe for GRK2 and represent a starting point for the rational design of more potent and specific GRK2 inhibitors.
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Affiliation(s)
- David M. Thal
- Life Sciences
Institute and
the Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Kristoff T. Homan
- Life Sciences
Institute and
the Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Jun Chen
- Center for Molecular Discovery, University of New Mexico Health Sciences Center, Albuquerque,
New Mexico 87131, United States
| | - Emily K. Wu
- Life Sciences
Institute and
the Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Patricia M. Hinkle
- Department of Pharmacology and
Physiology, University of Rochester Medical Center, Rochester, New York 14642, United States
| | - Z. Maggie Huang
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia,
Pennsylvania 19140, United States
| | - J. Kurt Chuprun
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia,
Pennsylvania 19140, United States
| | - Jianliang Song
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia,
Pennsylvania 19140, United States
| | - Erhe Gao
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia,
Pennsylvania 19140, United States
| | - Joseph Y. Cheung
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia,
Pennsylvania 19140, United States
| | - Larry A. Sklar
- Center for Molecular Discovery, University of New Mexico Health Sciences Center, Albuquerque,
New Mexico 87131, United States
| | - Walter J. Koch
- Center for Translational Medicine, Temple University School of Medicine, Philadelphia,
Pennsylvania 19140, United States
| | - John J.G. Tesmer
- Life Sciences
Institute and
the Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, United States
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17
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Orban T, Huang CC, Homan KT, Jastrzebska B, Tesmer JJG, Palczewski K. Substrate-induced changes in the dynamics of rhodopsin kinase (G protein-coupled receptor kinase 1). Biochemistry 2012; 51:3404-11. [PMID: 22480180 DOI: 10.1021/bi300295y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
G protein-coupled receptor (GPCR) kinases (GRKs) instigate the desensitization of activated GPCRs via phosphorylation that promotes interaction with arrestins, thereby preventing the interaction of GPCRs with heterotrimeric G proteins. A current proposed model of GRK1 activation involves the binding of activated rhodopsin (Rho*) to the N-terminal region of GRK1. Perhaps concomitantly, this N-terminal region also stabilizes a closed, active conformation of the kinase domain. To further probe this model, we mapped changes in the backbone flexibility of GRK1 as it binds to its two substrates, adenosine triphosphate (Mg(2+)·ATP) and Rho*. We found that the conformational flexibility of GRK1 was reduced in the presence of either Mg(2+)·ATP or Rho*, with Mg(2+)·ATP having the greatest effect. In a truncated form of GRK1 lacking the N-terminal region (ΔN-GRK1), peptides that directly interact with ATP were not as dramatically stabilized by adding Mg(2+)·ATP, and dynamics were greater in the interface between the large lobe of the kinase domain and the regulator of the G protein signaling homology domain. In the presence of Mg(2+)·ATP, the influence of Rho* versus Rho on GRK1 dynamics was negligible.
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Affiliation(s)
- Tivadar Orban
- Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106-4965, USA
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18
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Homan KT, Thal DM, Wu E, Chen J, Sklar L, Tesmer JJG. New Therapeutics Targeting Heart Failure: Development of GRK2 Selective Inhibitors. FASEB J 2012. [DOI: 10.1096/fasebj.26.1_supplement.665.8] [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)
| | - David M Thal
- Life Sciences InstituteUniversity of MichiganAnn ArborMI
| | - Emily Wu
- Life Sciences InstituteUniversity of MichiganAnn ArborMI
| | - Jun Chen
- Center for Molecular DiscoveryUniversity of New MexicoAlbuquerqueNM
| | - Larry Sklar
- Center for Molecular DiscoveryUniversity of New MexicoAlbuquerqueNM
| | - John JG Tesmer
- Life Sciences InstituteUniversity of MichiganAnn ArborMI
- PharmacologyUniversity of MichiganAnn ArborMI
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19
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Balasubramaniam D, Paul LN, Homan KT, Hall MC, Stauffacher CV. Specificity of HCPTP variants toward EphA2 tyrosines by quantitative selected reaction monitoring. Protein Sci 2011; 20:1172-81. [PMID: 21538645 DOI: 10.1002/pro.646] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2011] [Revised: 04/09/2011] [Accepted: 04/20/2011] [Indexed: 11/08/2022]
Abstract
EphA2 receptor tyrosine kinase and the human cytoplasmic protein tyrosine phosphatase (HCPTP) are overexpressed in a number of epithelial cancers. Overexpressed EphA2 in these cancers shows a significant decrease in phosphotyrosine content which results in suppression of receptor signaling and endocytosis and an increase in metastatic potential. The decreased phosphotyrosine content of EphA2 has been associated with decreased contact with its ligand, ephrin A1 and dephosphorylation by HCPTP. Potential specificity of the two HCPTP variants for tyrosines on EphA2 has not been investigated. We have used a mass spectrometry assay to measure relative rates of dephosphorylation for the two HCPTP variants at phosphotyrosine sites associated with control of the EphA2 kinase activity or interaction with downstream targets. Our results suggest that although both variants dephosphorylate the EphA2 receptor, the rate and specificity of dephosphorylation for specific tyrosines are different for HCPTP-A and HCPTP-B. The SAM domain tyrosine Y960 which has been implicated in downstream PI3K signaling is dephosphorylated exclusively by HCPTP-B. The activation loop tyrosine (Y772) which directly controls kinase activity is dephosphorylated about six times faster by HCPTP-A. In contrast, the juxtamembrane tyrosines (Y575, Y588 and Y594) which are implicated in both control of kinase activity and downstream signaling are dephosphorylated by both variants with similar rates. This difference in preference for dephosphorylation sites on EphA2 not only illuminates the different roles of the two variants of the phosphatase in EphA2 signaling, but also explains why both HCPTP variants are highly conserved in most mammals.
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Affiliation(s)
- Deepa Balasubramaniam
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana 47907, USA
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20
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Homan KT, Balasubramaniam D, Zabell APR, Wiest O, Helquist P, Stauffacher CV. Identification of novel inhibitors for a low molecular weight protein tyrosine phosphatase via virtual screening. Bioorg Med Chem 2010; 18:5449-56. [PMID: 20538467 DOI: 10.1016/j.bmc.2010.04.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2010] [Revised: 04/14/2010] [Accepted: 04/16/2010] [Indexed: 11/29/2022]
Abstract
The human cytoplasmic protein tyrosine phosphatase (HCPTP) has been identified as a potential target for inhibition in order to downregulate metastatic transformation in several human epithelial cancers such as breast, prostate and colon cancer. Docking with two scoring functions on both isoforms of HCPTP was employed as an initial virtual screen to identify potential inhibitors. Compounds identified as potential inhibitors via this in silico screen were subjected to kinetic analysis in order to validate their selection as improved inhibitors. Eleven compounds with IC50's of less than 100 microM were identified in a single concentration screen. Five of these compounds were determined to have an IC50 of less than 10 microM; however, all but one of these compounds inhibited via non-specific aggregation. The validated effective inhibitor, which is based on a naphthyl sulfonic acid, strongly resembles a previously synthesized rationally designed azaindole phosphonic acid. This similarity suggests subsequent inhibitor optimization based on this scaffold may generate effective inhibitors of HCPTP. The structural elements of the computationally identified inhibitors are discussed to analyze the combined use of rational design and virtual screening to reduce false negatives in the identification of multiple strong inhibitors of HCPTP.
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Affiliation(s)
- Kristoff T Homan
- Department of Biological Sciences and Purdue University Center for Cancer Research, Purdue University, 915 W. State Street, West Lafayette, IN 47907, United States
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21
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Helquist P, V. Stauffacher C, A. Weitgenant J, Katsuyama I, A. Bigi M, J. Corden S, T. Markiewicz J, P. R. Zabell A, T. Homan K, Wiest O. Synthesis of a 5-Azaindole Phosphonic Acid as a Computationally Designed Inhibitor of the Low Molecular Weight Phosphatase HCPTP. HETEROCYCLES 2006. [DOI: 10.3987/com-06-s(w)38] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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