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Gonzalez-Hernandez AJ, Munguba H, Levitz J. Emerging modes of regulation of neuromodulatory G protein-coupled receptors. Trends Neurosci 2024:S0166-2236(24)00088-2. [PMID: 38862331 DOI: 10.1016/j.tins.2024.05.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 05/16/2024] [Accepted: 05/21/2024] [Indexed: 06/13/2024]
Abstract
In the nervous system, G protein-coupled receptors (GPCRs) control neuronal excitability, synaptic transmission, synaptic plasticity, and, ultimately, behavior through spatiotemporally precise initiation of a variety of signaling pathways. However, despite their critical importance, there is incomplete understanding of how these receptors are regulated to tune their signaling to specific neurophysiological contexts. A deeper mechanistic picture of neuromodulatory GPCR function is needed to fully decipher their biological roles and effectively harness them for the treatment of neurological and psychiatric disorders. In this review, we highlight recent progress in identifying novel modes of regulation of neuromodulatory GPCRs, including G protein- and receptor-targeting mechanisms, receptor-receptor crosstalk, and unique features that emerge in the context of chemical synapses. These emerging principles of neuromodulatory GPCR tuning raise critical questions to be tackled at the molecular, cellular, synaptic, and neural circuit levels in the future.
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Affiliation(s)
| | - Hermany Munguba
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA; Department of Psychiatry, Weill Cornell Medicine, New York, NY 10065, USA
| | - Joshua Levitz
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA; Department of Psychiatry, Weill Cornell Medicine, New York, NY 10065, USA.
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2
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Rizk R, Devost D, Pétrin D, Hébert TE. KCTD Proteins Have Redundant Functions in Controlling Cellular Growth. Int J Mol Sci 2024; 25:4993. [PMID: 38732215 PMCID: PMC11084553 DOI: 10.3390/ijms25094993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Revised: 04/23/2024] [Accepted: 04/29/2024] [Indexed: 05/13/2024] Open
Abstract
We explored the functional redundancy of three structurally related KCTD (Potassium Channel Tetramerization Domain) proteins, KCTD2, KCTD5, and KCTD17, by progressively knocking them out in HEK 293 cells using CRISPR/Cas9 genome editing. After validating the knockout, we assessed the effects of progressive knockout on cell growth and gene expression. We noted that the progressive effects of knockout of KCTD isoforms on cell growth were most pervasive when all three isoforms were deleted, suggesting some functions were conserved between them. This was also reflected in progressive changes in gene expression. Our previous work indicated that Gβ1 was involved in the transcriptional control of gene expression, so we compared the gene expression patterns between GNB1 and KCTD KO. Knockout of GNB1 led to numerous changes in the expression levels of other G protein subunit genes, while knockout of KCTD isoforms had the opposite effect, presumably because of their role in regulating levels of Gβ1. Our work demonstrates a unique relationship between KCTD proteins and Gβ1 and a global role for this subfamily of KCTD proteins in maintaining the ability of cells to survive and proliferate.
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Affiliation(s)
| | | | | | - Terence E. Hébert
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir-William-Osler, Room 1303, Montréal, QC H3G 1Y6, Canada; (R.R.); (D.D.); (D.P.)
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3
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Nguyen DM, Rath DH, Devost D, Pétrin D, Rizk R, Ji AX, Narayanan N, Yong D, Zhai A, Kuntz DA, Mian MUQ, Pomroy NC, Keszei AFA, Benlekbir S, Mazhab-Jafari MT, Rubinstein JL, Hébert TE, Privé GG. Structure and dynamics of a pentameric KCTD5/CUL3/Gβγ E3 ubiquitin ligase complex. Proc Natl Acad Sci U S A 2024; 121:e2315018121. [PMID: 38625940 PMCID: PMC11047111 DOI: 10.1073/pnas.2315018121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 03/07/2024] [Indexed: 04/18/2024] Open
Abstract
Heterotrimeric G proteins can be regulated by posttranslational modifications, including ubiquitylation. KCTD5, a pentameric substrate receptor protein consisting of an N-terminal BTB domain and a C-terminal domain, engages CUL3 to form the central scaffold of a cullin-RING E3 ligase complex (CRL3KCTD5) that ubiquitylates Gβγ and reduces Gβγ protein levels in cells. The cryo-EM structure of a 5:5:5 KCTD5/CUL3NTD/Gβ1γ2 assembly reveals a highly dynamic complex with rotations of over 60° between the KCTD5BTB/CUL3NTD and KCTD5CTD/Gβγ moieties of the structure. CRL3KCTD5 engages the E3 ligase ARIH1 to ubiquitylate Gβγ in an E3-E3 superassembly, and extension of the structure to include full-length CUL3 with RBX1 and an ARIH1~ubiquitin conjugate reveals that some conformational states position the ARIH1~ubiquitin thioester bond to within 10 Å of lysine-23 of Gβ and likely represent priming complexes. Most previously described CRL/substrate structures have consisted of monovalent complexes and have involved flexible peptide substrates. The structure of the KCTD5/CUL3NTD/Gβγ complex shows that the oligomerization of a substrate receptor can generate a polyvalent E3 ligase complex and that the internal dynamics of the substrate receptor can position a structured target for ubiquitylation in a CRL3 complex.
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Affiliation(s)
- Duc Minh Nguyen
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A8, Canada
| | - Deanna H. Rath
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | - Dominic Devost
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QCH3G 1Y6, Canada
| | - Darlaine Pétrin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QCH3G 1Y6, Canada
| | - Robert Rizk
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QCH3G 1Y6, Canada
| | - Alan X. Ji
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A8, Canada
| | - Naveen Narayanan
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | - Darren Yong
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | - Andrew Zhai
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | - Douglas A. Kuntz
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | - Maha U. Q. Mian
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | - Neil C. Pomroy
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
| | | | - Samir Benlekbir
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
| | - Mohammad T. Mazhab-Jafari
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ONM5G 2M9, Canada
| | - John L. Rubinstein
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A8, Canada
- Molecular Medicine Program, The Hospital for Sick Children, Toronto, ONM5G 0A4, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ONM5G 2M9, Canada
| | - Terence E. Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QCH3G 1Y6, Canada
| | - Gilbert G. Privé
- Princess Margaret Cancer Centre, University Health Network, Toronto, ONM5G 1L7, Canada
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A8, Canada
- Department of Medical Biophysics, University of Toronto, Toronto, ONM5G 2M9, Canada
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4
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Miller KA, Cruz Walma DA, Pinkas DM, Tooze RS, Bufton JC, Richardson W, Manning CE, Hunt AE, Cros J, Hartill V, Parker MJ, McGowan SJ, Twigg SRF, Chalk R, Staunton D, Johnson D, Wilkie AOM, Bullock AN. BTB domain mutations perturbing KCTD15 oligomerisation cause a distinctive frontonasal dysplasia syndrome. J Med Genet 2024; 61:490-501. [PMID: 38296633 DOI: 10.1136/jmg-2023-109531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 12/21/2023] [Indexed: 02/02/2024]
Abstract
INTRODUCTION KCTD15 encodes an oligomeric BTB domain protein reported to inhibit neural crest formation through repression of Wnt/beta-catenin signalling, as well as transactivation by TFAP2. Heterozygous missense variants in the closely related paralogue KCTD1 cause scalp-ear-nipple syndrome. METHODS Exome sequencing was performed on a two-generation family affected by a distinctive phenotype comprising a lipomatous frontonasal malformation, anosmia, cutis aplasia of the scalp and/or sparse hair, and congenital heart disease. Identification of a de novo missense substitution within KCTD15 led to targeted sequencing of DNA from a similarly affected sporadic patient, revealing a different missense mutation. Structural and biophysical analyses were performed to assess the effects of both amino acid substitutions on the KCTD15 protein. RESULTS A heterozygous c.310G>C variant encoding p.(Asp104His) within the BTB domain of KCTD15 was identified in an affected father and daughter and segregated with the phenotype. In the sporadically affected patient, a de novo heterozygous c.263G>A variant encoding p.(Gly88Asp) was present in KCTD15. Both substitutions were found to perturb the pentameric assembly of the BTB domain. A crystal structure of the BTB domain variant p.(Gly88Asp) revealed a closed hexameric assembly, whereas biophysical analyses showed that the p.(Asp104His) substitution resulted in a monomeric BTB domain likely to be partially unfolded at physiological temperatures. CONCLUSION BTB domain substitutions in KCTD1 and KCTD15 cause clinically overlapping phenotypes involving craniofacial abnormalities and cutis aplasia. The structural analyses demonstrate that missense substitutions act through a dominant negative mechanism by disrupting the higher order structure of the KCTD15 protein complex.
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Affiliation(s)
- Kerry A Miller
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - David A Cruz Walma
- Centre for Medicines Discovery, University of Oxford, Oxford, UK
- Cell Biology Section, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, Maryland, USA
| | - Daniel M Pinkas
- Centre for Medicines Discovery, University of Oxford, Oxford, UK
- Department of Biological Sciences, Universidad Loyola Andalucía, Seville, Spain
| | - Rebecca S Tooze
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Joshua C Bufton
- Centre for Medicines Discovery, University of Oxford, Oxford, UK
| | | | | | - Alice E Hunt
- Centre for Medicines Discovery, University of Oxford, Oxford, UK
| | - Julien Cros
- Centre for Medicines Discovery, University of Oxford, Oxford, UK
| | - Verity Hartill
- Leeds Institute of Medical Research, University of Leeds, Leeds, UK
- Yorkshire Regional Genetics Service, Leeds Teaching Hospitals NHS Trust, Chapel Allerton Hospital, Leeds, UK
| | - Michael J Parker
- Sheffield Clinical Genomics Service, Sheffield Children's Hospital NHS Foundation Trust, Sheffield, UK
| | - Simon J McGowan
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Stephen R F Twigg
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
| | - Rod Chalk
- Centre for Medicines Discovery, University of Oxford, Oxford, UK
| | - David Staunton
- Department of Biochemistry, University of Oxford, Oxford, UK
| | - David Johnson
- Craniofacial Unit, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Andrew O M Wilkie
- MRC Weatherall Institute of Molecular Medicine, University of Oxford, Oxford, UK
- Craniofacial Unit, Oxford University Hospitals NHS Foundation Trust, Oxford, UK
| | - Alex N Bullock
- Centre for Medicines Discovery, University of Oxford, Oxford, UK
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5
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Fritzius T, Tureček R, Fernandez-Fernandez D, Isogai S, Rem PD, Kralikova M, Gassmann M, Bettler B. Preassembly of specific Gβγ subunits at GABA B receptors through auxiliary KCTD proteins accelerates channel gating. Biochem Pharmacol 2024:116176. [PMID: 38555036 DOI: 10.1016/j.bcp.2024.116176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 03/15/2024] [Accepted: 03/26/2024] [Indexed: 04/02/2024]
Abstract
GABAB receptors (GBRs) are G protein-coupled receptors for GABA, the main inhibitory neurotransmitter in the brain. GBRs regulate fast synaptic transmission by gating Ca2+ and K+ channels via the Gβγ subunits of the activated G protein. It has been demonstrated that auxiliary GBR subunits, the KCTD proteins, shorten onset and rise time and increase desensitization of receptor-induced K+ currents. KCTD proteins increase desensitization of K+ currents by scavenging Gβγ from the channel, yet the mechanism responsible for the rapid activation of K+ currents has remained elusive. In this study, we demonstrate that KCTD proteins preassemble Gβγ at GBRs. The preassembly obviates the need for diffusion-limited G protein recruitment to the receptor, thereby accelerating G protein activation and, as a result, K+ channel activation. Preassembly of Gβγ at the receptor relies on the interaction of KCTD proteins with a loop protruding from the seven-bladed propeller of Gβ subunits. The binding site is shared between Gβ1 and Gβ2, limiting the interaction of KCTD proteins to these particular Gβ isoforms. Substituting residues in the KCTD binding site of Gβ1 with those from Gβ3 hinders the preassembly of Gβγ with GBRs, delays onset and prolongs rise time of receptor-activated K+ currents. The KCTD-Gβ interface, therefore, represents a target for pharmacological modulation of channel gating by GBRs.
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Affiliation(s)
| | - Rostislav Tureček
- Department of Biomedicine, University of Basel, Basel, Switzerland; Department of Auditory Neuroscience, Institute of Experimental Medicine CAS, Prague, Czech Republic
| | | | - Shin Isogai
- Microbial Downstream Process Development, Lonza AG, Visp, Switzerland
| | - Pascal D Rem
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Michaela Kralikova
- Department of Auditory Neuroscience, Institute of Experimental Medicine CAS, Prague, Czech Republic
| | - Martin Gassmann
- Department of Biomedicine, University of Basel, Basel, Switzerland
| | - Bernhard Bettler
- Department of Biomedicine, University of Basel, Basel, Switzerland.
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6
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Balasco N, Esposito L, Smaldone G, Salvatore M, Vitagliano L. A Comprehensive Analysis of the Structural Recognition between KCTD Proteins and Cullin 3. Int J Mol Sci 2024; 25:1881. [PMID: 38339159 PMCID: PMC10856315 DOI: 10.3390/ijms25031881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 01/19/2024] [Accepted: 01/28/2024] [Indexed: 02/12/2024] Open
Abstract
KCTD ((K)potassium Channel Tetramerization Domain-containing) proteins constitute an emerging class of proteins involved in fundamental physio-pathological processes. In these proteins, the BTB domain, which represents the defining element of the family, may have the dual role of promoting oligomerization and favoring functionally important partnerships with different interactors. Here, by exploiting the potential of recently developed methodologies for protein structure prediction, we report a comprehensive analysis of the interactions of all KCTD proteins with their most common partner Cullin 3 (Cul3). The data here presented demonstrate the impressive ability of this approach to discriminate between KCTDs that interact with Cul3 and those that do not. Indeed, reliable and stable models of the complexes were only obtained for the 15 members of the family that are known to interact with Cul3. The generation of three-dimensional models for all KCTD-Cul3 complexes provides interesting clues on the determinants of the structural basis of this partnership as clear structural differences emerged between KCTDs that bind or do not bind Cul3. Finally, the availability of accurate three-dimensional models for KCTD-Cul3 interactions may be valuable for the ad hoc design and development of compounds targeting specific KCTDs that are involved in several common diseases.
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Affiliation(s)
- Nicole Balasco
- Institute of Molecular Biology and Pathology, CNR c/o Department Chemistry, Sapienza University of Rome, 00185 Rome, Italy
| | - Luciana Esposito
- Institute of Biostructures and Bioimaging, CNR, 80131 Naples, Italy;
| | | | | | - Luigi Vitagliano
- Institute of Biostructures and Bioimaging, CNR, 80131 Naples, Italy;
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7
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Negrutskii BS, Porubleva LV, Malinowska A, Novosylna OV, Dadlez M, Knudsen CR. Understanding functions of eEF1 translation elongation factors beyond translation. A proteomic approach. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 138:67-99. [PMID: 38220433 DOI: 10.1016/bs.apcsb.2023.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2024]
Abstract
Mammalian translation elongation factors eEF1A1 and eEF1A2 are 92% homologous isoforms whose mutually exclusive tissue-specific expression is regulated during development. The isoforms have similar translation functionality, but show differences in spatial organization and participation in various processes, such as oncogenesis and virus reproduction. The differences may be due to their ability to interact with isoform-specific partner proteins. We used the identified sets of eEF1A1 or eEF1A2 partner proteins to identify cell complexes and/or processes specific to one particular isoform. As a result, we found isoform-specific interactions reflecting the involvement of different eEF1A isoforms in different cellular processes, including actin-related, chromatin-remodeling, ribonuclease H2, adenylyl cyclase, and Cul3-RING ubiquitin ligase complexes as well as initiation of mitochondrial transcription. An essential by-product of our analysis is the elucidation of a number of cellular processes beyond protein biosynthesis, where both isoforms appear to participate such as large ribosomal subunit biogenesis, mRNA splicing, DNA mismatch repair, 26S proteasome activity, P-body and exosomes formation, protein targeting to the membrane. This information suggests that a relatively high content of eEF1A in the cell may be necessary not only to maintain efficient translation, but also to ensure its participation in various cellular processes, where some roles of eEF1A have not yet been described. We believe that the data presented here will be useful for deciphering new auxiliary functions of eEF1A and its isoforms, and provide a new look at the known non-canonical functions of this main component of the human translation-elongation machinery.
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Affiliation(s)
- Boris S Negrutskii
- Institute of Molecular Biology and Genetics, Kyiv, Ukraine; Aarhus Institute of Advanced Sciences, Høegh-Guldbergs, Aarhus C, Denmark; Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen, Aarhus C, Denmark.
| | | | - Agata Malinowska
- Institute of Biochemistry and Biophysics, PAN, Pawinskiego, Warsaw, Poland
| | | | - Michal Dadlez
- Institute of Biochemistry and Biophysics, PAN, Pawinskiego, Warsaw, Poland
| | - Charlotte R Knudsen
- Department of Molecular Biology and Genetics, Aarhus University, Universitetsbyen, Aarhus C, Denmark
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8
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Liao Y, Sloan DC, Widjaja JH, Muntean BS. KCTD5 Forms Hetero-Oligomeric Complexes with Various Members of the KCTD Protein Family. Int J Mol Sci 2023; 24:14317. [PMID: 37762619 PMCID: PMC10531988 DOI: 10.3390/ijms241814317] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/14/2023] [Accepted: 09/15/2023] [Indexed: 09/29/2023] Open
Abstract
Potassium Channel Tetramerization Domain 5 (KCTD5) regulates diverse aspects of physiology, ranging from neuronal signaling to colorectal cancer. A key feature of KCTD5 is its self-assembly into multi-subunit oligomers that seemingly enables participation in an array of protein-protein interactions. KCTD5 has recently been reported to form hetero-oligomeric complexes with two similar KCTDs (KCTD2 and KCTD17). However, it is not known if KCTD5 forms hetero-oligomeric complexes with the remaining KCTD protein family which contains over two dozen members. Here, we demonstrate that KCTD5 interacts with various KCTD proteins when assayed through co-immunoprecipitation in lysed cells. We reinforced this dataset by examining KCTD5 interactions in a live-cell bioluminescence resonance energy transfer (BRET)-based approach. Finally, we developed an IP-luminescence approach to map regions on KCTD5 required for interaction with a selection of KCTD that have established roles in neuronal signaling. We report that different regions on KCTD5 are responsible for uniquely contributing to interactions with other KCTD proteins. While our results help unravel additional interaction partners for KCTD5, they also reveal additional complexities in KCTDs' biology. Moreover, our findings also suggest that KCTD hetero-oligomeric interactions may occur throughout the KCTD family.
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Affiliation(s)
| | | | | | - Brian S. Muntean
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; (Y.L.); (J.H.W.)
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9
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Jiang W, Wang W, Kong Y, Zheng S. Structural basis for the ubiquitination of G protein βγ subunits by KCTD5/Cullin3 E3 ligase. SCIENCE ADVANCES 2023; 9:eadg8369. [PMID: 37450587 PMCID: PMC10348674 DOI: 10.1126/sciadv.adg8369] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/24/2023] [Accepted: 06/14/2023] [Indexed: 07/18/2023]
Abstract
G protein-coupled receptor (GPCR) signaling is precisely controlled to avoid overstimulation that results in detrimental consequences. Gβγ signaling is negatively regulated by a Cullin3 (Cul3)-dependent E3 ligase, KCTD5, which triggers ubiquitination and degradation of free Gβγ. Here, we report the cryo-electron microscopy structures of the KCTD5-Gβγ fusion complex and the KCTD7-Cul3 complex. KCTD5 in pentameric form engages symmetrically with five copies of Gβγ through its C-terminal domain. The unique pentameric assembly of the KCTD5/Cul3 E3 ligase places the ubiquitin-conjugating enzyme (E2) and the modification sites of Gβγ in close proximity and allows simultaneous transfer of ubiquitin from E2 to five Gβγ subunits. Moreover, we show that ubiquitination of Gβγ by KCTD5 is important for fine-tuning cyclic adenosine 3´,5´-monophosphate signaling of GPCRs. Our studies provide unprecedented insights into mechanisms of substrate recognition by unusual pentameric E3 ligases and highlight the KCTD family as emerging regulators of GPCR signaling.
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Affiliation(s)
- Wentong Jiang
- Graduate School of Peking Union Medical College, Beijing 100730, China
- National Institute of Biological Sciences, Beijing 102206, China
| | - Wei Wang
- National Institute of Biological Sciences, Beijing 102206, China
- School of Life Sciences, Peking University, Beijing 100871, China
| | - Yinfei Kong
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Sanduo Zheng
- Graduate School of Peking Union Medical College, Beijing 100730, China
- National Institute of Biological Sciences, Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 100084, China
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10
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Aguilan JT, Pedrosa E, Dolstra H, Baykara RN, Barnes J, Zhang J, Sidoli S, Lachman HM. Proteomics and phosphoproteomics profiling in glutamatergic neurons and microglia in an iPSC model of Jansen de Vries Syndrome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.08.548192. [PMID: 37461463 PMCID: PMC10350077 DOI: 10.1101/2023.07.08.548192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Background Jansen de Vries Syndrome (JdVS) is a rare neurodevelopmental disorder (NDD) caused by gain-of-function (GOF) truncating mutations in PPM1D exons 5 or 6. PPM1D is a serine/threonine phosphatase that plays an important role in the DNA damage response (DDR) by negatively regulating TP53 (P53). JdVS-associated mutations lead to the formation of a truncated PPM1D protein that retains catalytic activity and has a GOF effect because of reduced degradation. Somatic PPM1D exons 5 and 6 truncating mutations are well-established factors in a number of cancers, due to excessive dephosphorylation and reduced function of P53 and other substrates involved in DDR. Children with JdVS have a variety of neurodevelopmental, psychiatric, and physical problems. In addition, a small fraction has acute neuropsychiatric decompensation apparently triggered by infection or severe non-infectious environmental stress factors. Methods To understand the molecular basis of JdVS, we developed an induced pluripotent stem cell (iPSC) model system. iPSCs heterozygous for the truncating variant (PPM1D+/tr), were made from a patient, and control lines engineered using CRISPR-Cas9 gene editing. Proteomics and phosphoprotemics analyses were carried out on iPSC-derived glutamatergic neurons and microglia from three control and three PPM1D+/tr iPSC lines. We also analyzed the effect of the TLR4 agonist, lipopolysaccharide, to understand how activation of the innate immune system in microglia could account for acute behavioral decompensation. Results One of the major findings was the downregulation of POGZ in unstimulated microglia. Since loss-of-function variants in the POGZ gene are well-known causes of autism spectrum disorder, the decrease in PPM1D+/tr microglia suggests this plays a role in the neurodevelopmental aspects of JdVS. In addition, neurons, baseline, and LPS-stimulated microglia show marked alterations in the expression of several E3 ubiquitin ligases, most notably UBR4, and regulators of innate immunity, chromatin structure, ErbB signaling, and splicing. In addition, pathway analysis points to overlap with neurodegenerative disorders. Limitations Owing to the cost and labor-intensive nature of iPSC research, the sample size was small. Conclusions Our findings provide insight into the molecular basis of JdVS and can be extrapolated to understand neuropsychiatric decompensation that occurs in subgroups of patients with ASD and other NDDs.
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Affiliation(s)
- Jennifer T. Aguilan
- Department of Pathology, Albert Einstein College of Medicine, 1300 Morris Park Ave. Bronx, NY, 10461
| | - Erika Pedrosa
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave. Bronx, NY, 10461
| | - Hedwig Dolstra
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave. Bronx, NY, 10461
| | - Refia Nur Baykara
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave. Bronx, NY, 10461
| | - Jesse Barnes
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave. Bronx, NY, 10461
| | - Jinghang Zhang
- Department of Microbiology & Immunology, Albert Einstein College of Medicine, 1300 Morris Park Ave. Bronx, NY, 10461
| | - Simone Sidoli
- Department of Biochemistry, Albert Einstein College of Medicine, 1300 Morris Park Ave. Bronx, NY, 10461
| | - Herbert M. Lachman
- Department of Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, 1300 Morris Park Ave. Bronx, NY, 10461
- Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Ave. Bronx, NY, 10461
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave. Bronx, NY, 10461
- Department of Genetics, Albert Einstein College of Medicine, 1300 Morris Park Ave. Bronx, NY, 10461
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Multiple potassium channel tetramerization domain (KCTD) family members interact with Gβγ, with effects on cAMP signaling. J Biol Chem 2023; 299:102924. [PMID: 36736897 PMCID: PMC9976452 DOI: 10.1016/j.jbc.2023.102924] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 01/04/2023] [Accepted: 01/05/2023] [Indexed: 02/04/2023] Open
Abstract
G protein-coupled receptors (GPCRs) initiate an array of intracellular signaling programs by activating heterotrimeric G proteins (Gα and Gβγ subunits). Therefore, G protein modifiers are well positioned to shape GPCR pharmacology. A few members of the potassium channel tetramerization domain (KCTD) protein family have been found to adjust G protein signaling through interaction with Gβγ. However, comprehensive details on the KCTD interaction with Gβγ remain unresolved. Here, we report that nearly all the 25 KCTD proteins interact with Gβγ. In this study, we screened Gβγ interaction capacity across the entire KCTD family using two parallel approaches. In a live cell bioluminescence resonance energy transfer-based assay, we find that roughly half of KCTD proteins interact with Gβγ in an agonist-induced fashion, whereas all KCTD proteins except two were found to interact through coimmunoprecipitation. We observed that the interaction was dependent on an amino acid hot spot in the C terminus of KCTD2, KCTD5, and KCTD17. While KCTD2 and KCTD5 require both the Bric-à-brac, Tramtrack, Broad complex domain and C-terminal regions for Gβγ interaction, we uncovered that the KCTD17 C terminus is sufficient for Gβγ interaction. Finally, we demonstrated the functional consequence of the KCTD-Gβγ interaction by examining sensitization of the adenylyl cyclase-cAMP pathway in live cells. We found that Gβγ-mediated sensitization of adenylyl cyclase 5 was blunted by KCTD. We conclude that the KCTD family broadly engages Gβγ to shape GPCR signal transmission.
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Members of the KCTD family are major regulators of cAMP signaling. Proc Natl Acad Sci U S A 2022; 119:2119237119. [PMID: 34934014 PMCID: PMC8740737 DOI: 10.1073/pnas.2119237119] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2021] [Indexed: 11/18/2022] Open
Abstract
Neuromodulation is pivotal for brain function. One of the key pathways engaged by neuromodulators is signaling via second messenger cAMP, which controls a myriad of fundamental reactions. This study identifies KCTD5, a ubiquitin ligase adapter, as a regulatory element in this pathway and determines that it works by an unusual dual mode controlling the activity of cAMP-generating enzyme in neurons through both zinc transport and G protein signaling. Cyclic adenosine monophosphate (cAMP) is a pivotal second messenger with an essential role in neuronal function. cAMP synthesis by adenylyl cyclases (AC) is controlled by G protein–coupled receptor (GPCR) signaling systems. However, the network of molecular players involved in the process is incompletely defined. Here, we used CRISPR/Cas9–based screening to identify that members of the potassium channel tetradimerization domain (KCTD) family are major regulators of cAMP signaling. Focusing on striatal neurons, we show that the dominant isoform KCTD5 exerts its effects through an unusual mechanism that modulates the influx of Zn2+ via the Zip14 transporter to exert unique allosteric effects on AC. We further show that KCTD5 controls the amplitude and sensitivity of stimulatory GPCR inputs to cAMP production by Gβγ-mediated AC regulation. Finally, we report that KCTD5 haploinsufficiency in mice leads to motor deficits that can be reversed by chelating Zn2+. Together, our findings uncover KCTD proteins as major regulators of neuronal cAMP signaling via diverse mechanisms.
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