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Peach CJ, Kilpatrick LE, Friedman-Ohana R, Zimmerman K, Robers MB, Wood KV, Woolard J, Hill SJ. Real-Time Ligand Binding of Fluorescent VEGF-A Isoforms that Discriminate between VEGFR2 and NRP1 in Living Cells. Cell Chem Biol 2018; 25:1208-1218.e5. [PMID: 30057299 PMCID: PMC6200776 DOI: 10.1016/j.chembiol.2018.06.012] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 05/23/2018] [Accepted: 06/29/2018] [Indexed: 12/20/2022]
Abstract
Fluorescent VEGF-A isoforms have been evaluated for their ability to discriminate between VEGFR2 and NRP1 in real-time ligand binding studies in live cells using BRET. To enable this, we synthesized single-site (N-terminal cysteine) labeled versions of VEGF165a, VEGF165b, and VEGF121a. These were used in combination with N-terminal NanoLuc-tagged VEGFR2 or NRP1 to evaluate the selectivity of VEGF isoforms for these two membrane proteins. All fluorescent VEGF-A isoforms displayed high affinity for VEGFR2. Only VEGF165a-TMR bound to NanoLuc-NRP1 with a similar high affinity (4.4 nM). Competition NRP1 binding experiments yielded a rank order of potency of VEGF165a > VEGF189a > VEGF145a. VEGF165b, VEGF-Ax, VEGF121a, and VEGF111a were unable to bind to NRP1. There were marked differences in the kinetic binding profiles of VEGF165a-TMR for NRP1 and VEGFR2. These data emphasize the importance of the kinetic aspects of ligand binding to VEGFR2 and its co-receptors in the dynamics of VEGF signaling. VEGF165a, VEGF121a, and VEGF165b were single-site labeled with tetramethylrhodamine NanoBRET quantified that VEGF-A isoforms have similar binding properties at VEGFR2 NRP1 expressed in live cells does not bind VEGF165b, VEGF121a, VEGF-Ax, or VEGF111a VEGFR2 and NRP1 have markedly distinct kinetic profiles binding VEGF165a-TMR
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Affiliation(s)
- Chloe J Peach
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Nottingham NG7 2UH, UK
| | - Laura E Kilpatrick
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Nottingham NG7 2UH, UK
| | | | - Kris Zimmerman
- Promega Corporation, 2800 Woods Hollow Road, Madison, WI 53711, USA
| | - Matthew B Robers
- Promega Corporation, 2800 Woods Hollow Road, Madison, WI 53711, USA
| | - Keith V Wood
- Promega Corporation, 2800 Woods Hollow Road, Madison, WI 53711, USA
| | - Jeanette Woolard
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Nottingham NG7 2UH, UK.
| | - Stephen J Hill
- Division of Physiology, Pharmacology and Neuroscience, School of Life Sciences, University of Nottingham, Nottingham NG7 2UH, UK; Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Nottingham NG7 2UH, UK.
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Deering-Rice CE, Mitchell VK, Romero EG, Abdel Aziz MH, Ryskamp DA, Križaj D, Gopal VR, Reilly CA. Drofenine: A 2-APB Analogue with Greater Selectivity for Human TRPV3. Pharmacol Res Perspect 2014; 2:e00062. [PMID: 25089200 PMCID: PMC4115637 DOI: 10.1002/prp2.62] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [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] [Indexed: 12/15/2022] Open
Abstract
Transient receptor potential vanilloid-3 (TRPV3) is a member of the TRPV subfamily of TRP ion channels. The physiological functions of TRPV3 are not fully understood, in part, due to a lack of selective agonists and antagonists that could both facilitate the elucidation of roles for TRPV3 in mammalian physiology as well as potentially serve as therapeutic agents to modulate conditions for which altered TRPV3 function has been implicated. In this study, the Microsource Spectrum Collection was screened for TRPV3 agonists and antagonists using alterations in calcium flux in TRPV3 overexpressing human embryonic kidney-293 (HEK-293) cells. The antispasmodic agent drofenine was identified as a new TRPV3 agonist. Drofenine exhibited similar potency to the known TRPV3 agonists 2-aminoethoxydiphenylboronate (2-APB) and carvacrol in HEK-293 cells, but greater selectivity for TRPV3 based on a lack of activation of TRPA1, V1, V2, V4, or M8. Multiple inhibitors were also identified, but all of the compounds were either inactive or not specific. Drofenine activated TRPV3 via interactions with the residue, H426, which is required for TRPV3 activation by 2-APB. Drofenine was a more potent agonist of TRPV3 and more cytotoxic than either carvacrol or 2-APB in human keratinocytes and its effect on TRPV3 in HaCaT cells was further demonstrated using the antagonist icilin. Due to the lack of specificity of existing TRPV3 modulators and the expression of multiple TRP channels in cells/tissue, drofenine may be a valuable probe for elucidating TRPV3 functions in complex biological systems. Identification of TRPV3 as a target for drofenine may also suggest a mechanism by which drofenine acts as a therapeutic agent.
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Affiliation(s)
- Cassandra E Deering-Rice
- Department of Pharmacology and Toxicology, University of Utah, 30 S. 2000 E., Room 201 Skaggs Hall, Salt Lake City, UT 84112, USA
| | - Virginia K Mitchell
- Department of Pharmacology and Toxicology, University of Utah, 30 S. 2000 E., Room 201 Skaggs Hall, Salt Lake City, UT 84112, USA
| | - Erin G Romero
- Department of Pharmacology and Toxicology, University of Utah, 30 S. 2000 E., Room 201 Skaggs Hall, Salt Lake City, UT 84112, USA
| | - May H Abdel Aziz
- Department of Pharmacology and Toxicology, University of Utah, 30 S. 2000 E., Room 201 Skaggs Hall, Salt Lake City, UT 84112, USA
| | - Daniel A Ryskamp
- Department of Ophthalmology & Visual Sciences, Interdepartmental Neuroscience Program, University of Utah, Room S4140 Moran Eye Center, Salt Lake City, UT 84132, USA
| | - David Križaj
- Department of Ophthalmology & Visual Sciences, Interdepartmental Neuroscience Program, University of Utah, Room S4140 Moran Eye Center, Salt Lake City, UT 84132, USA
| | - V Raj Gopal
- Department of Medicinal Chemistry, University of Utah, Salt Lake City, UT 84112
| | - Christopher A Reilly
- Department of Pharmacology and Toxicology, University of Utah, 30 S. 2000 E., Room 201 Skaggs Hall, Salt Lake City, UT 84112, USA
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Abstract
Functional selectivity is the term that describes drugs that cause markedly different signaling through a single receptor (e.g., full agonist at one pathway and antagonist at a second). It has been widely recognized recently that this phenomenon impacts the understanding of mechanism of action of some drugs, and has relevance to drug discovery. One of the clinical areas where this mechanism has particular importance is in the treatment of schizophrenia. Antipsychotic drugs have been grouped according to both pattern of clinical action and mechanism of action. The original antipsychotic drugs such as chlorpromazine and haloperidol have been called typical or first generation. They cause both antipsychotic actions and many side effects (extrapyramidal and endocrine) that are ascribed to their high affinity dopamine D(2) receptor antagonism. Drugs such as clozapine, olanzapine, risperidone and others were then developed that avoided the neurological side effects (atypical or second generation antipsychotics). These compounds are divided mechanistically into those that are high affinity D(2) and 5-HT(2A) antagonists, and those that also bind with modest affinity to D(2), 5-HT(2A), and many other neuroreceptors. There is one approved third generation drug, aripiprazole, whose actions have been ascribed alternately to either D(2) partial agonism or D(2) functional selectivity. Although partial agonism has been the more widely accepted mechanism, the available data are inconsistent with this mechanism. Conversely, the D(2) functional selectivity hypothesis can accommodate all current data for aripiprazole, and also impacts on discovery compounds that are not pure D(2) antagonists.
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Affiliation(s)
- Richard B Mailman
- Penn State University College of Medicine - Milton S. Hershey Medical Center Department of Pharmacology. R130 500 University Dr., PO Box 850, Hershey, PA 17033-0850, USA.
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