Other search tools

About this data

The publication data currently available has been vetted by Vanderbilt faculty, staff, administrators and trainees. The data itself is retrieved directly from NCBI's PubMed and is automatically updated on a weekly basis to ensure accuracy and completeness.

If you have any questions or comments, please contact us.

Results: 1 to 10 of 202

Publication Record

Connections

Structure-function analyses of the ion channel TRPC3 reveal that its cytoplasmic domain allosterically modulates channel gating.
Sierra-Valdez F, Azumaya CM, Romero LO, Nakagawa T, Cordero-Morales JF
(2018) J Biol Chem 293: 16102-16114
MeSH Terms: Allosteric Regulation, Ankyrin Repeat, HEK293 Cells, Humans, Ion Channel Gating, Mutation, Protein Conformation, alpha-Helical, Protein Domains, TRPC Cation Channels
Show Abstract · Added April 10, 2019
The transient receptor potential ion channels support Ca permeation in many organs, including the heart, brain, and kidney. Genetic mutations in transient receptor potential cation channel subfamily C member 3 (TRPC3) are associated with neurodegenerative diseases, memory loss, and hypertension. To better understand the conformational changes that regulate TRPC3 function, we solved the cryo-EM structures for the full-length human TRPC3 and its cytoplasmic domain (CPD) in the apo state at 5.8- and 4.0-Å resolution, respectively. These structures revealed that the TRPC3 transmembrane domain resembles those of other TRP channels and that the CPD is a stable module involved in channel assembly and gating. We observed the presence of a C-terminal domain swap at the center of the CPD where horizontal helices (HHs) transition into a coiled-coil bundle. Comparison of TRPC3 structures revealed that the HHs can reside in two distinct positions. Electrophysiological analyses disclosed that shortening the length of the C-terminal loop connecting the HH with the TRP helices increases TRPC3 activity and that elongating the length of the loop has the opposite effect. Our findings indicate that the C-terminal loop affects channel gating by altering the allosteric coupling between the cytoplasmic and transmembrane domains. We propose that molecules that target the HH may represent a promising strategy for controlling TRPC3-associated neurological disorders and hypertension.
© 2018 Sierra-Valdez et al.
0 Communities
1 Members
0 Resources
9 MeSH Terms
Allostery between two binding sites in the ion channel subunit TRIP8b confers binding specificity to HCN channels.
Lyman KA, Han Y, Heuermann RJ, Cheng X, Kurz JE, Lyman RE, Van Veldhoven PP, Chetkovich DM
(2017) J Biol Chem 292: 17718-17730
MeSH Terms: Allosteric Regulation, Binding Sites, HEK293 Cells, Humans, Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels, Protein Subunits, Receptors, Cytoplasmic and Nuclear
Show Abstract · Added April 2, 2019
Tetratricopeptide repeat (TPR) domains are ubiquitous structural motifs that mediate protein-protein interactions. For example, the TPR domains in the peroxisomal import receptor PEX5 enable binding to a range of type 1 peroxisomal targeting signal motifs. A homolog of PEX5, tetratricopeptide repeat-containing Rab8b-interacting protein (TRIP8b), binds to and functions as an auxiliary subunit of hyperpolarization-activated cyclic nucleotide (HCN)-gated channels. Given the similarity between TRIP8b and PEX5, this difference in function raises the question of what mechanism accounts for their binding specificity. In this report, we found that the cyclic nucleotide-binding domain and the C terminus of the HCN channel are critical for conferring specificity to TRIP8b binding. We show that TRIP8b binds the HCN cyclic nucleotide-binding domain through a 37-residue domain and the HCN C terminus through the TPR domains. Using a combination of fluorescence polarization- and co-immunoprecipitation-based assays, we establish that binding at either site increases affinity at the other. Thus, allosteric coupling of the TRIP8b TPR domains both promotes binding to HCN channels and limits binding to type 1 peroxisomal targeting signal substrates. These results raise the possibility that other TPR domains may be similarly influenced by allosteric mechanisms as a general feature of protein-protein interactions.
© 2017 by The American Society for Biochemistry and Molecular Biology, Inc.
0 Communities
1 Members
0 Resources
MeSH Terms
Identification and Characterization of the First Selective Y Receptor Positive Allosteric Modulator.
Schubert M, Stichel J, Du Y, Tough IR, Sliwoski G, Meiler J, Cox HM, Weaver CD, Beck-Sickinger AG
(2017) J Med Chem 60: 7605-7612
MeSH Terms: Allosteric Regulation, Animals, Arrestins, COS Cells, Cercopithecus aethiops, Cyclohexanols, GTP-Binding Proteins, HEK293 Cells, Humans, Models, Molecular, Receptors, Neuropeptide Y, Signal Transduction
Show Abstract · Added March 17, 2018
The human Y receptor (YR) and its cognate ligand, pancreatic polypeptide (PP), are involved in the regulation of energy expenditure, satiety, and food intake. This system represents a potential target for the treatment of metabolic diseases and has been extensively investigated and validated in vivo. Here, we present the compound tBPC (tert-butylphenoxycyclohexanol), a novel and selective YR positive allosteric modulator that potentiates YR activation in G-protein signaling and arrestin3 recruitment experiments. The compound has no effect on the binding of the orthosteric ligands, implying its allosteric mode of action at the YR and evidence for a purely efficacy-driven positive allosteric modulation. Finally, the ability of tBPC to selectively potentiate YR agonism initiated by PP was confirmed in mouse descending colon mucosa preparations expressing native YR, demonstrating YR positive allosteric modulation in vitro.
0 Communities
2 Members
0 Resources
12 MeSH Terms
cytochrome P450 46A1 (CYP46A1) activation by neuroactive compounds.
Mast N, Anderson KW, Johnson KM, Phan TTN, Guengerich FP, Pikuleva IA
(2017) J Biol Chem 292: 12934-12946
MeSH Terms: Acetylcholine, Allosteric Regulation, Amino Acid Substitution, Anti-HIV Agents, Aspartic Acid, Benzoxazines, Binding Sites, Biocatalysis, Cholesterol 24-Hydroxylase, Deuterium Exchange Measurement, Enzyme Activation, Glutamic Acid, Ligands, Models, Molecular, Molecular Docking Simulation, Mutagenesis, Site-Directed, Mutation, Nerve Tissue Proteins, Peptide Fragments, Protein Conformation, Recombinant Fusion Proteins, gamma-Aminobutyric Acid
Show Abstract · Added March 14, 2018
Cytochrome P450 46A1 (CYP46A1, cholesterol 24-hydroxylase) is the enzyme responsible for the majority of cholesterol elimination from the brain. Previously, we found that the anti-HIV drug efavirenz (EFV) can pharmacologically activate CYP46A1 in mice. Herein, we investigated whether CYP46A1 could also be activated by endogenous compounds, including major neurotransmitters. experiments with purified recombinant CYP46A1 indicated that CYP46A1 is activated by l-glutamate (l-Glu), l-aspartate, γ-aminobutyric acid, and acetylcholine, with l-Glu eliciting the highest increase (3-fold) in CYP46A1-mediated cholesterol 24-hydroxylation. We also found that l-Glu and other activating neurotransmitters bind to the same site on the CYP46A1 surface, which differs from the EFV-binding site. The other principal differences between EFV and l-Glu in CYP46A1 activation include an apparent lack of l-Glu binding to the P450 active site and different pathways of signal transduction from the allosteric site to the active site. EFV and l-Glu similarly increased the CYP46A1 , the rate of the "fast" phase of the enzyme reduction by the redox partner NADPH-cytochrome P450 oxidoreductase, and the amount of P450 reduced. Spectral titrations with cholesterol, in the presence of EFV or l-Glu, suggest that water displacement from the heme iron can be affected in activator-bound CYP46A1. Moreover, EFV and l-Glu synergistically activated CYP46A1. Collectively, our data, along with those from previous cell culture and studies by others, suggest that l-Glu-induced CYP46A1 activation is of physiological relevance.
© 2017 by The American Society for Biochemistry and Molecular Biology, Inc.
0 Communities
1 Members
0 Resources
22 MeSH Terms
Discovery of N-(5-Fluoropyridin-2-yl)-6-methyl-4-(pyrimidin-5-yloxy)picolinamide (VU0424238): A Novel Negative Allosteric Modulator of Metabotropic Glutamate Receptor Subtype 5 Selected for Clinical Evaluation.
Felts AS, Rodriguez AL, Blobaum AL, Morrison RD, Bates BS, Thompson Gray A, Rook JM, Tantawy MN, Byers FW, Chang S, Venable DF, Luscombe VB, Tamagnan GD, Niswender CM, Daniels JS, Jones CK, Conn PJ, Lindsley CW, Emmitte KA
(2017) J Med Chem 60: 5072-5085
MeSH Terms: Allosteric Regulation, Aminopyridines, Animals, Chemistry Techniques, Synthetic, Drug Evaluation, Preclinical, HEK293 Cells, High-Throughput Screening Assays, Humans, Macaca fascicularis, Male, Mice, Inbred Strains, Picolinic Acids, Rats, Sprague-Dawley, Receptor, Metabotropic Glutamate 5, Structure-Activity Relationship, Tissue Distribution
Show Abstract · Added March 21, 2018
Preclinical evidence in support of the potential utility of mGlu NAMs for the treatment of a variety of psychiatric and neurodegenerative disorders is extensive, and multiple such molecules have entered clinical trials. Despite some promising results from clinical studies, no small molecule mGlu NAM has yet to reach market. Here we present the discovery and evaluation of N-(5-fluoropyridin-2-yl)-6-methyl-4-(pyrimidin-5-yloxy)picolinamide (27, VU0424238), a compound selected for clinical evaluation. Compound 27 is more than 900-fold selective for mGlu versus the other mGlu receptors, and binding studies established a K value of 4.4 nM at a known allosteric binding site. Compound 27 had a clearance of 19.3 and 15.5 mL/min/kg in rats and cynomolgus monkeys, respectively. Imaging studies using a known mGlu PET ligand demonstrated 50% receptor occupancy at an oral dose of 0.8 mg/kg in rats and an intravenous dose of 0.06 mg/kg in baboons.
0 Communities
2 Members
0 Resources
16 MeSH Terms
Diverse Effects on M Signaling and Adverse Effect Liability within a Series of M Ago-PAMs.
Rook JM, Abe M, Cho HP, Nance KD, Luscombe VB, Adams JJ, Dickerson JW, Remke DH, Garcia-Barrantes PM, Engers DW, Engers JL, Chang S, Foster JJ, Blobaum AL, Niswender CM, Jones CK, Conn PJ, Lindsley CW
(2017) ACS Chem Neurosci 8: 866-883
MeSH Terms: Allosteric Regulation, Animals, Drug Discovery, Humans, Mice, Muscarinic Agonists, Rats, Receptor, Muscarinic M1, Structure-Activity Relationship
Show Abstract · Added April 6, 2017
Both historical clinical and recent preclinical data suggest that the M muscarinic acetylcholine receptor is an exciting target for the treatment of Alzheimer's disease and the cognitive and negative symptom clusters in schizophrenia; however, early drug discovery efforts targeting the orthosteric binding site have failed to afford selective M activation. Efforts then shifted to focus on selective activation of M via either allosteric agonists or positive allosteric modulators (PAMs). While M PAMs have robust efficacy in rodent models, some chemotypes can induce cholinergic adverse effects (AEs) that could limit their clinical utility. Here, we report studies aimed at understanding the subtle structural and pharmacological nuances that differentiate efficacy from adverse effect liability within an indole-based series of M ago-PAMs. Our data demonstrate that closely related M PAMs can display striking differences in their in vivo activities, especially their propensities to induce adverse effects. We report the discovery of a novel PAM in this series that is devoid of observable adverse effect liability. Interestingly, the molecular pharmacology profile of this novel PAM is similar to that of a representative M PAM that induces severe AEs. For instance, both compounds are potent ago-PAMs that demonstrate significant interaction with the orthosteric site (either bitopic or negative cooperativity). However, there are subtle differences in efficacies of the compounds at potentiating M responses, agonist potencies, and abilities to induce receptor internalization. While these differences may contribute to the differential in vivo profiles of these compounds, the in vitro differences are relatively subtle and highlight the complexities of allosteric modulators and the need to focus on in vivo phenotypic screening to identify safe and effective M PAMs.
0 Communities
2 Members
0 Resources
9 MeSH Terms
Antipsychotic-like Effects of M4 Positive Allosteric Modulators Are Mediated by CB2 Receptor-Dependent Inhibition of Dopamine Release.
Foster DJ, Wilson JM, Remke DH, Mahmood MS, Uddin MJ, Wess J, Patel S, Marnett LJ, Niswender CM, Jones CK, Xiang Z, Lindsley CW, Rook JM, Conn PJ
(2016) Neuron 91: 1244-1252
MeSH Terms: Allosteric Regulation, Animals, Antipsychotic Agents, Corpus Striatum, Dopamine, Lipoprotein Lipase, Mice, Knockout, Muscarinic Agonists, Oxotremorine, Prepulse Inhibition, Pyridazines, Receptor, Cannabinoid, CB2, Receptor, Muscarinic M4, Thiophenes
Show Abstract · Added April 6, 2017
Muscarinic receptors represent a promising therapeutic target for schizophrenia, but the mechanisms underlying the antipsychotic efficacy of muscarinic modulators are not well understood. Here, we report that activation of M4 receptors on striatal spiny projection neurons results in a novel form of dopaminergic regulation resulting in a sustained depression of striatal dopamine release that is observed more than 30 min after removal of the muscarinic receptor agonist. Furthermore, both the M4-mediated sustained inhibition of dopamine release and the antipsychotic-like efficacy of M4 activators were found to require intact signaling through CB2 cannabinoid receptors. These findings highlight a novel mechanism by which striatal cholinergic and cannabinoid signaling leads to sustained reductions in dopaminergic transmission and concurrent behavioral effects predictive of antipsychotic efficacy.
Copyright © 2016 Elsevier Inc. All rights reserved.
0 Communities
4 Members
0 Resources
14 MeSH Terms
Discovery and SAR of a novel series of potent, CNS penetrant M4 PAMs based on a non-enolizable ketone core: Challenges in disposition.
Wood MR, Noetzel MJ, Tarr JC, Rodriguez AL, Lamsal A, Chang S, Foster JJ, Smith E, Chase P, Hodder PS, Engers DW, Niswender CM, Brandon NJ, Wood MW, Duggan ME, Conn PJ, Bridges TM, Lindsley CW
(2016) Bioorg Med Chem Lett 26: 4282-6
MeSH Terms: Allosteric Regulation, Animals, Central Nervous System, Drug Discovery, Humans, Ketones, Molecular Structure, Receptor, Muscarinic M1, Structure-Activity Relationship
Show Abstract · Added April 6, 2017
This Letter describes the chemical optimization of a novel series of M4 PAMs based on a non-enolizable ketone core, identified from an MLPCN functional high-throughput screen. The HTS hit was potent, selective and CNS penetrant; however, the compound was highly cleared in vitro and in vivo. SAR provided analogs for which M4 PAM potency and CNS exposure were maintained; yet, clearance remained high. Metabolite identification studies demonstrated that this series was subject to rapid, and near quantitative, reductive metabolism to the corresponding secondary alcohol metabolite that was devoid of M4 PAM activity.
Copyright © 2016 Elsevier Ltd. All rights reserved.
0 Communities
1 Members
0 Resources
9 MeSH Terms
Biased allosteric agonism and modulation of metabotropic glutamate receptor 5: Implications for optimizing preclinical neuroscience drug discovery.
Sengmany K, Singh J, Stewart GD, Conn PJ, Christopoulos A, Gregory KJ
(2017) Neuropharmacology 115: 60-72
MeSH Terms: Allosteric Regulation, Animals, Calcium Signaling, Dose-Response Relationship, Drug, Drug Discovery, Drug Evaluation, Preclinical, Excitatory Amino Acid Agonists, Excitatory Amino Acid Antagonists, Female, HEK293 Cells, Humans, MAP Kinase Signaling System, Mice, Receptor, Metabotropic Glutamate 5
Show Abstract · Added April 6, 2017
Allosteric modulators, that exhibit no intrinsic agonist activity, offer the advantage of spatial and temporal fine-tuning of endogenous agonist activity, allowing the potential for increased selectivity, reduced adverse effects and improved clinical outcomes. Some allosteric ligands can differentially activate and/or modulate distinct signaling pathways arising from the same receptor, phenomena referred to as 'biased agonism' and 'biased modulation'. Emerging evidence for CNS disorders with glutamatergic dysfunction suggests the metabotropic glutamate receptor subtype 5 (mGlu) is a promising target. Current mGlu allosteric modulators have largely been classified based on modulation of intracellular calcium (iCa) responses to orthosteric agonists alone. We assessed eight mGlu allosteric modulators previously classified as mGlu PAMs or PAM-agonists representing four distinct chemotypes across multiple measures of receptor activity, to explore their potential for engendering biased agonism and/or modulation. Relative to the reference orthosteric agonist, DHPG, the eight allosteric ligands exhibited distinct biased agonism fingerprints for iCa mobilization, IP accumulation and ERK1/2 phosphorylation in HEK293A cells stably expressing mGlu and in cortical neuron cultures. VU0424465, DPFE and VU0409551 displayed the most disparate biased signaling fingerprints in both HEK293A cells and cortical neurons that may account for the marked differences observed previously for these ligands in vivo. Select mGlu allosteric ligands also showed 'probe dependence' with respect to their cooperativity with different orthosteric agonists, as well as biased modulation for the magnitude of positive cooperativity observed. Unappreciated biased agonism and modulation may contribute to unanticipated effects (both therapeutic and adverse) when translating from recombinant systems to preclinical models. This article is part of the Special Issue entitled 'Metabotropic Glutamate Receptors, 5 years on'.
Copyright © 2016 Elsevier Ltd. All rights reserved.
0 Communities
1 Members
0 Resources
14 MeSH Terms
The Role of mGlu Receptors in Hippocampal Plasticity Deficits in Neurological and Psychiatric Disorders: Implications for Allosteric Modulators as Novel Therapeutic Strategies.
Senter RK, Ghoshal A, Walker AG, Xiang Z, Niswender CM, Conn PJ
(2016) Curr Neuropharmacol 14: 455-73
MeSH Terms: Allosteric Regulation, Animals, Excitatory Amino Acid Agents, Hippocampus, Humans, Mental Disorders, Neuronal Plasticity, Psychotropic Drugs, Receptors, Metabotropic Glutamate
Show Abstract · Added April 6, 2017
Long-term potentiation (LTP) and long-term depression (LTD) are two distinct forms of synaptic plasticity that have been extensively characterized at the Schaffer collateral-CA1 (SCCA1) synapse and the mossy fiber (MF)-CA3 synapse within the hippocampus, and are postulated to be the molecular underpinning for several cognitive functions. Deficits in LTP and LTD have been implicated in the pathophysiology of several neurological and psychiatric disorders. Therefore, there has been a large effort focused on developing an understanding of the mechanisms underlying these forms of plasticity and novel therapeutic strategies that improve or rescue these plasticity deficits. Among many other targets, the metabotropic glutamate (mGlu) receptors show promise as novel therapeutic candidates for the treatment of these disorders. Among the eight distinct mGlu receptor subtypes (mGlu1-8), the mGlu1,2,3,5,7 subtypes are expressed throughout the hippocampus and have been shown to play important roles in the regulation of synaptic plasticity in this brain area. However, development of therapeutic agents that target these mGlu receptors has been hampered by a lack of subtype-selective compounds. Recently, discovery of allosteric modulators of mGlu receptors has provided novel ligands that are highly selective for individual mGlu receptor subtypes. The mGlu receptors modulate the multiple forms of synaptic plasticity at both SC-CA1 and MF synapses and allosteric modulators of mGlu receptors have emerged as potential therapeutic agents that may rescue plasticity deficits and improve cognitive function in patients suffering from multiple neurological and psychiatric disorders.
0 Communities
1 Members
0 Resources
9 MeSH Terms