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Watkins HA, Chakravarthy M, Abhayawardana RS, Gingell JJ, Garelja M, Pardamwar M, McElhinney JMWR, Lathbridge A, Constantine A, Harris PWR, Yuen TY, Brimble MA, Barwell J, Poyner DR, Woolley MJ, Conner AC, Pioszak AA, Reynolds CA, Hay DL. Receptor Activity-modifying Proteins 2 and 3 Generate Adrenomedullin Receptor Subtypes with Distinct Molecular Properties. J Biol Chem 2016; 291:11657-75. [PMID: 27013657 PMCID: PMC4882435 DOI: 10.1074/jbc.m115.688218] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 03/20/2016] [Indexed: 01/28/2023] Open
Abstract
Adrenomedullin (AM) is a peptide hormone with numerous effects in the vascular systems. AM signals through the AM1 and AM2 receptors formed by the obligate heterodimerization of a G protein-coupled receptor, the calcitonin receptor-like receptor (CLR), and receptor activity-modifying proteins 2 and 3 (RAMP2 and RAMP3), respectively. These different CLR-RAMP interactions yield discrete receptor pharmacology and physiological effects. The effective design of therapeutics that target the individual AM receptors is dependent on understanding the molecular details of the effects of RAMPs on CLR. To understand the role of RAMP2 and -3 on the activation and conformation of the CLR subunit of AM receptors, we mutated 68 individual amino acids in the juxtamembrane region of CLR, a key region for activation of AM receptors, and determined the effects on cAMP signaling. Sixteen CLR mutations had differential effects between the AM1 and AM2 receptors. Accompanying this, independent molecular modeling of the full-length AM-bound AM1 and AM2 receptors predicted differences in the binding pocket and differences in the electrostatic potential of the two AM receptors. Druggability analysis indicated unique features that could be used to develop selective small molecule ligands for each receptor. The interaction of RAMP2 or RAMP3 with CLR induces conformational variation in the juxtamembrane region, yielding distinct binding pockets, probably via an allosteric mechanism. These subtype-specific differences have implications for the design of therapeutics aimed at specific AM receptors and for understanding the mechanisms by which accessory proteins affect G protein-coupled receptor function.
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Affiliation(s)
- Harriet A Watkins
- From the School of Biological Sciences, the Maurice Wilkins Centre for Molecular Biodiscovery, and
| | | | | | - Joseph J Gingell
- From the School of Biological Sciences, the Maurice Wilkins Centre for Molecular Biodiscovery, and
| | | | - Meenakshi Pardamwar
- the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
| | - James M W R McElhinney
- the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
| | - Alex Lathbridge
- the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
| | - Arran Constantine
- the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
| | - Paul W R Harris
- the Maurice Wilkins Centre for Molecular Biodiscovery, and the School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Tsz-Ying Yuen
- the Maurice Wilkins Centre for Molecular Biodiscovery, and the School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand
| | - Margaret A Brimble
- the Maurice Wilkins Centre for Molecular Biodiscovery, and the School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand
| | - James Barwell
- the School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, United Kingdom
| | - David R Poyner
- the School of Life and Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, United Kingdom
| | - Michael J Woolley
- the School of Clinical and Experimental Medicine, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Alex C Conner
- the School of Clinical and Experimental Medicine, University of Birmingham, Edgbaston, Birmingham B15 2TT, United Kingdom
| | - Augen A Pioszak
- the Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104
| | - Christopher A Reynolds
- the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom,
| | - Debbie L Hay
- From the School of Biological Sciences, the Maurice Wilkins Centre for Molecular Biodiscovery, and
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Taddese B, Upton GJ, Bailey GR, Jordan SR, Abdulla NY, Reeves PJ, Reynolds CA. Do plants contain g protein-coupled receptors? PLANT PHYSIOLOGY 2014; 164:287-307. [PMID: 24246381 PMCID: PMC3875809 DOI: 10.1104/pp.113.228874] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 11/16/2013] [Indexed: 05/05/2023]
Abstract
Whether G protein-coupled receptors (GPCRs) exist in plants is a fundamental biological question. Interest in deorphanizing new GPCRs arises because of their importance in signaling. Within plants, this is controversial, as genome analysis has identified 56 putative GPCRs, including G protein-coupled receptor1 (GCR1), which is reportedly a remote homolog to class A, B, and E GPCRs. Of these, GCR2 is not a GPCR; more recently, it has been proposed that none are, not even GCR1. We have addressed this disparity between genome analysis and biological evidence through a structural bioinformatics study, involving fold recognition methods, from which only GCR1 emerges as a strong candidate. To further probe GCR1, we have developed a novel helix-alignment method, which has been benchmarked against the class A-class B-class F GPCR alignments. In addition, we have presented a mutually consistent set of alignments of GCR1 homologs to class A, class B, and class F GPCRs and shown that GCR1 is closer to class A and/or class B GPCRs than class A, class B, or class F GPCRs are to each other. To further probe GCR1, we have aligned transmembrane helix 3 of GCR1 to each of the six GPCR classes. Variability comparisons provide additional evidence that GCR1 homologs have the GPCR fold. From the alignments and a GCR1 comparative model, we have identified motifs that are common to GCR1, class A, B, and E GPCRs. We discuss the possibilities that emerge from this controversial evidence that GCR1 has a GPCR fold.
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Affiliation(s)
| | - Graham J.G. Upton
- School of Biological Sciences (B.T., G.R.B., S.R.D.J., N.Y.A., P.J.R., C.A.R.) and Department of Mathematical Sciences (G.J.G.U.), University of Essex, Colchester, CO4 3SQ United Kingdom
| | - Gregory R. Bailey
- School of Biological Sciences (B.T., G.R.B., S.R.D.J., N.Y.A., P.J.R., C.A.R.) and Department of Mathematical Sciences (G.J.G.U.), University of Essex, Colchester, CO4 3SQ United Kingdom
| | - Siân R.D. Jordan
- School of Biological Sciences (B.T., G.R.B., S.R.D.J., N.Y.A., P.J.R., C.A.R.) and Department of Mathematical Sciences (G.J.G.U.), University of Essex, Colchester, CO4 3SQ United Kingdom
| | - Nuradin Y. Abdulla
- School of Biological Sciences (B.T., G.R.B., S.R.D.J., N.Y.A., P.J.R., C.A.R.) and Department of Mathematical Sciences (G.J.G.U.), University of Essex, Colchester, CO4 3SQ United Kingdom
| | - Philip J. Reeves
- School of Biological Sciences (B.T., G.R.B., S.R.D.J., N.Y.A., P.J.R., C.A.R.) and Department of Mathematical Sciences (G.J.G.U.), University of Essex, Colchester, CO4 3SQ United Kingdom
| | - Christopher A. Reynolds
- School of Biological Sciences (B.T., G.R.B., S.R.D.J., N.Y.A., P.J.R., C.A.R.) and Department of Mathematical Sciences (G.J.G.U.), University of Essex, Colchester, CO4 3SQ United Kingdom
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