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Pandey M, Zhang JH, Adikaram PR, Kittock CM, Lue N, Awe AM, Degner KN, Jacob N, Staples JN, Thomas R, Kohnen AB, Ganesan S, Kabat J, Chen CK, Simonds WF. Specific regulation of mechanical nociception by Gβ5 involves GABA-B receptors. JCI Insight 2023:134685. [PMID: 37219953 PMCID: PMC10371342 DOI: 10.1172/jci.insight.134685] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023] Open
Abstract
Mechanical, thermal, and chemical pain sensation is conveyed by primary nociceptors, a subset of sensory afferent neurons. The intracellular regulation of the primary nociceptive signal is an area of active study. We report here the discovery of a Gβ5-dependent regulatory pathway within mechanical nociceptors that restrains anti-nociceptive input from metabotropic GABA-B receptors. In mice with conditional knockout (cKO) of Gnb5 targeted to peripheral sensory neurons, we demonstrate the impairment of mechanical, thermal, and chemical nociception. We further report the specific loss of mechanical nociception in Rgs7-Cre+/-; Gnb5fl/fl mice but not in Rgs9-Cre+/-; Gnb5fl/fl mice, suggesting that Gβ5 might specifically regulate mechanical pain in Rgs7+ cells. Additionally, Gβ5-dependent and Rgs7-associated mechanical nociception is dependent upon GABA-B receptor signaling since both were abolished by treatment with a GABA-B receptor antagonist and since cKO of Gβ5 from sensory cells or from Rgs7+ cells potentiated the analgesic effects of GABA-B agonists. Following activation by the Mrgprd agonist β-alanine, enhanced sensitivity to inhibition by baclofen was observed in primary cultures of Rgs7+ sensory neurons harvested from Rgs7-Cre+/-; Gnb5fl/fl mice. Taken together, these results suggest that the targeted inhibition of Gβ5 function in Rgs7+ sensory neurons might provide specific relief for mechanical allodynia, including that contributing to chronic neuropathic pain, without reliance on exogenous opioids.
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Affiliation(s)
- Mritunjay Pandey
- Metabolic Diseases Branch, National Institutes of Health, NIDDK, Bethesda, United States of America
| | - Jian-Hua Zhang
- Metabolic Diseases Branch, National Institutes of Health, NIDDK, Bethesda, United States of America
| | - Poorni R Adikaram
- Metabolic Diseases Branch, National Institutes of Health, NIDDK, Bethesda, United States of America
| | - Claire M Kittock
- Metabolic Diseases Branch, National Institutes of Health, NIDDK, Bethesda, United States of America
| | - Nicole Lue
- Metabolic Diseases Branch, National Institutes of Health, NIDDK, Bethesda, United States of America
| | - Adam M Awe
- Metabolic Diseases Branch, National Institutes of Health, NIDDK, Bethesda, United States of America
| | - Katherine N Degner
- Metabolic Diseases Branch, National Institutes of Health, NIDDK, Bethesda, United States of America
| | - Nirmal Jacob
- Metabolic Diseases Branch, National Institutes of Health, NIDDK, Bethesda, United States of America
| | - Jenna N Staples
- Metabolic Diseases Branch, National Institutes of Health, NIDDK, Bethesda, United States of America
| | - Rachel Thomas
- Metabolic Diseases Branch, National Institutes of Health, NIDDK, Bethesda, United States of America
| | - Allison B Kohnen
- Metabolic Diseases Branch, National Institutes of Health, NIDDK, Bethesda, United States of America
| | | | - Juraj Kabat
- NIAID, NIH, Bethesda, United States of America
| | - Ching-Kang Chen
- Department of Molecular Medicine, The University of Texas Health Science Center at San Antonio, San Antonio, United States of America
| | - William F Simonds
- Metabolic Diseases Branch, National Institutes of Health, NIDDK, Bethesda, United States of America
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Li Y, Zhang J, Adikaram PR, Welch J, Guan B, Weinstein LS, Chen H, Simonds WF. Genotype of CDC73 germline mutation determines risk of parathyroid cancer. Endocr Relat Cancer 2020; 27:483-494. [PMID: 32590342 PMCID: PMC8802173 DOI: 10.1530/erc-20-0149] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 06/25/2020] [Indexed: 11/08/2022]
Abstract
Mutation of the CDC73 gene, which encodes parafibromin, has been linked with parathyroid cancer. However, no correlation between genotypes of germline CDC73 mutations and the risk of parathyroid cancer has been known. In this study, subjects with germline CDC73 mutations were identified from the participants of two clinical protocols at National Institutes of Health (Discovery Cohort) and from the literature (Validation Cohort). The relative risk of developing parathyroid cancer was analyzed as a function of CDC73 genotype, and the impact of representative mutations on structure of parafibromin was compared between genotype groups. A total of 419 subjects, 68 in Discovery Cohort and 351 in Validation Cohort, were included. In both cohorts, percentages of CDC73 germline mutations that predicted significant conformational disruption or loss of expression of parafibromin (referred as 'high-impact mutations') were significantly higher among the subjects with parathyroid cancers compared to all other subjects. The Kaplan-Meier analysis showed that high-impact mutations were associated with a 6.6-fold higher risk of parathyroid carcinoma compared to low-impact mutations, despite a similar risk of developing primary hyperparathyroidism between two groups. Disruption of the C-terminal domain (CTD) of parafibromin is directly involved in predisposition to parathyroid carcinoma, since only the mutations impacting this domain were associated with an increased risk of parathyroid carcinoma. Structural analysis revealed that a conserved surface structure in the CTD is universally disrupted by the mutations affecting this domain. In conclusion, high-impact germline CDC73 mutations were found to increase risk of parathyroid carcinoma by disrupting the CTD of parafibromin.
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Affiliation(s)
- Yulong Li
- Division of Endocrinology, Department of Medicine, Penn State University College of Medicine, Hershey, Pennsylvania, USA
| | - Jianhua Zhang
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Poorni R Adikaram
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - James Welch
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Bin Guan
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Lee S Weinstein
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Haobin Chen
- Thoracic Surgery Branch, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - William F Simonds
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, USA
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Adikaram PR, Zhang JH, Kittock CM, Pandey M, Hassan SA, Lue NG, Wang G, Gucek M, Simonds WF. Development of R7BP inhibitors through cross-linking coupled mass spectrometry and integrated modeling. Commun Biol 2019; 2:338. [PMID: 31531399 PMCID: PMC6744478 DOI: 10.1038/s42003-019-0585-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [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: 02/27/2019] [Accepted: 08/21/2019] [Indexed: 02/08/2023] Open
Abstract
Protein-protein interaction (PPI) networks are known to be valuable targets for therapeutic intervention; yet the development of PPI modulators as next-generation drugs to target specific vertices, edges, and hubs has been impeded by the lack of structural information of many of the proteins and complexes involved. Building on recent advancements in cross-linking mass spectrometry (XL-MS), we describe an effective approach to obtain relevant structural data on R7BP, a master regulator of itch sensation, and its interfaces with other proteins in its network. This approach integrates XL-MS with a variety of modeling techniques to successfully develop antibody inhibitors of the R7BP and RGS7/Gβ5 duplex interaction. Binding and inhibitory efficiency are studied by surface plasmon resonance spectroscopy and through an R7BP-derived dominant negative construct. This approach may have broader applications as a tool to facilitate the development of PPI modulators in the absence of crystal structures or when structural information is limited.
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Affiliation(s)
- Poorni R. Adikaram
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bldg. 10/Rm 8C-101, Bethesda, MD 20892 USA
| | - Jian-Hua Zhang
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bldg. 10/Rm 8C-101, Bethesda, MD 20892 USA
| | - Claire M. Kittock
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bldg. 10/Rm 8C-101, Bethesda, MD 20892 USA
| | - Mritunjay Pandey
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bldg. 10/Rm 8C-101, Bethesda, MD 20892 USA
| | - Sergio A. Hassan
- Center for Molecular Modeling, Center for Information Technology, Bldg. 12/Rm 2049, Bethesda, MD 20892 USA
| | - Nicole G. Lue
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bldg. 10/Rm 8C-101, Bethesda, MD 20892 USA
| | - Guanghui Wang
- Proteomics Core, National Heart Lung and Blood Institute, National Institutes of Health, Bldg. 10/Rm 8C-103A, Bethesda, MD 20892 USA
| | - Marjan Gucek
- Proteomics Core, National Heart Lung and Blood Institute, National Institutes of Health, Bldg. 10/Rm 8C-103A, Bethesda, MD 20892 USA
| | - William F. Simonds
- Metabolic Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bldg. 10/Rm 8C-101, Bethesda, MD 20892 USA
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Adikaram PR, Zhang J, Pandey M, Kittock C, Simonds WF. Structure and Interaction Analysis of Human R7‐RGS/Gβ5/R7BP complexes. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.652.9] [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]
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Adikaram PR, Beckett D. Protein:protein interactions in control of a transcriptional switch. J Mol Biol 2013; 425:4584-94. [PMID: 23896299 DOI: 10.1016/j.jmb.2013.07.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [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: 06/13/2013] [Revised: 07/17/2013] [Accepted: 07/19/2013] [Indexed: 12/01/2022]
Abstract
Protein partner exchange plays a key role in regulating many biological switches. Although widespread, the mechanisms dictating protein partner identity and, therefore, the outcome of a switch have been determined for a limited number of systems. The Escherichia coli protein BirA undergoes a switch between posttranslational biotin attachment and transcription repression in response to cellular biotin demand. Moreover, the functional switch reflects formation of alternative mutually exclusive protein:protein interactions by BirA. Previous studies provided a set of alanine-substituted BirA variants with altered kinetic and equilibrium parameters of forming these interactions. In this work, DNase I footprinting measurements were employed to investigate the consequences of these altered properties for the outcome of the BirA functional switch. The results support a mechanism in which BirA availability for DNA binding and, therefore, transcription repression is controlled by the rate of the competing protein:protein interaction. However, occupancy of the transcriptional regulatory site on DNA by BirA is exquisitely tuned by the equilibrium constant governing its homodimerization.
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Affiliation(s)
- Poorni R Adikaram
- Department of Chemistry and Biochemistry, College of Computer, Mathematical and Natural Sciences, University of Maryland, College Park, MD 20742, USA
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Adikaram PR, Beckett D. Functional versatility of a single protein surface in two protein:protein interactions. J Mol Biol 2012; 419:223-33. [PMID: 22446587 DOI: 10.1016/j.jmb.2012.03.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [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: 12/08/2011] [Revised: 03/12/2012] [Accepted: 03/14/2012] [Indexed: 11/18/2022]
Abstract
The ability of the Escherichia coli protein BirA to function as both a metabolic enzyme and a transcription repressor relies on the use of a single surface for two distinct protein:protein interactions. BirA forms a heterodimer with the biotin acceptor protein of acetyl-coenzyme A carboxylase and catalyzes posttranslational biotinylation. Alternatively, it forms a homodimer that binds sequence-specifically to DNA to repress transcription initiation at the biotin biosynthetic operon. Several surface loops on BirA, two of which exhibit sequence conservation in all biotin protein ligases and the remainder of which are highly variable, are located at the two interfaces. The function of these loops in both homodimerization and biotin transfer was investigated by characterizing alanine-substituted variants at 18 positions of one constant and three variable loops. Sedimentation equilibrium measurements reveal that 11 of the substitutions, which are distributed throughout conserved and variable loops, significantly alter homodimerization energetics. By contrast, steady-state and single-turnover kinetic measurements indicate that biotin transfer to biotin carboxyl carrier protein is impacted by seven substitutions, the majority of which are in the constant loop. Furthermore, constant loop residues that function in biotin transfer also support homodimerization. The results reveal clues about the evolution of a single protein surface for use in two distinct functions.
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Affiliation(s)
- Poorni R Adikaram
- Department of Chemistry and Biochemistry and Center for Biomolecular Structure and Organization, University of Maryland, College Park, MD 20742, USA
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