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Chen Y, Xia X, Zhang Y, Gao L, He C, Cao J. Case Report: New presentation of CLIFAHDD syndrome with a novel variant in the NALCN gene and a literature review. Front Pediatr 2024; 12:1370790. [PMID: 38873579 PMCID: PMC11169720 DOI: 10.3389/fped.2024.1370790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 05/08/2024] [Indexed: 06/15/2024] Open
Abstract
Background Congenital contractures of the limbs and face, hypotonia, and developmental delay (CLIFAHDD) syndrome (OMIM #616266) is an autosomal dominant hereditary disease that can lead to the congenital contracture of the limbs and face, hypotonia, and developmental delay. In addition, it may result in growth retardation and present various clinical symptoms, such as brain atrophy, a small pituitary gland, musculoskeletal abnormalities, abnormal breathing, abdominal hernia, and abnormal facial features. Herein, we describe a novel de novo missense genetic variant in the sodium leak channel, non-selective (NALCN) gene that is associated with CLIFAHDD syndrome. Case description This study describes a patient with varus deformities in both feet, deviation of the ulnar side of the fingers, and severe hypotonia. This patient was subsequently confirmed to have CLIFAHDD syndrome through genetic testing, which also revealed a novel missense de novo genetic variant in the NALCN gene (c.3553G > A, p.Ala1185Thr). Conclusions Our findings further enrich the known variant spectrum of the NALCN gene and may expand the range of clinical options for treating NALCN-related disorders.
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Affiliation(s)
| | | | | | | | | | - Jianguo Cao
- Department of Rehabilitation Medicine, Shenzhen Children’s Hospital, Shenzhen, China
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Schott K, Usher SG, Serra O, Carnevale V, Pless SA, Chua HC. Unplugging lateral fenestrations of NALCN reveals a hidden drug binding site within the pore region. Proc Natl Acad Sci U S A 2024; 121:e2401591121. [PMID: 38787877 PMCID: PMC11145269 DOI: 10.1073/pnas.2401591121] [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: 01/23/2024] [Accepted: 04/09/2024] [Indexed: 05/26/2024] Open
Abstract
The sodium (Na+) leak channel (NALCN) is a member of the four-domain voltage-gated cation channel family that includes the prototypical voltage-gated sodium and calcium channels (NaVs and CaVs, respectively). Unlike NaVs and CaVs, which have four lateral fenestrations that serve as routes for lipophilic compounds to enter the central cavity to modulate channel function, NALCN has bulky residues (W311, L588, M1145, and Y1436) that block these openings. Structural data suggest that occluded fenestrations underlie the pharmacological resistance of NALCN, but functional evidence is lacking. To test this hypothesis, we unplugged the fenestrations of NALCN by substituting the four aforementioned residues with alanine (AAAA) and compared the effects of NaV, CaV, and NALCN blockers on both wild-type (WT) and AAAA channels. Most compounds behaved in a similar manner on both channels, but phenytoin and 2-aminoethoxydiphenyl borate (2-APB) elicited additional, distinct responses on AAAA channels. Further experiments using single alanine mutants revealed that phenytoin and 2-APB enter the inner cavity through distinct fenestrations, implying structural specificity to their modes of access. Using a combination of computational and functional approaches, we identified amino acid residues critical for 2-APB activity, supporting the existence of drug binding site(s) within the pore region. Intrigued by the activity of 2-APB and its analogues, we tested compounds containing the diphenylmethane/amine moiety on WT channels. We identified clinically used drugs that exhibited diverse activity, thus expanding the pharmacological toolbox for NALCN. While the low potencies of active compounds reiterate the pharmacological resistance of NALCN, our findings lay the foundation for rational drug design to develop NALCN modulators with refined properties.
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Affiliation(s)
- Katharina Schott
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen2100, Denmark
| | - Samuel George Usher
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen2100, Denmark
| | - Oscar Serra
- Department of Biology, Temple University, Philadelphia, PA19122
- Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, PA19122
- Institute of Computational Molecular Science, Temple University, Philadelphia, PA19122
| | - Vincenzo Carnevale
- Department of Biology, Temple University, Philadelphia, PA19122
- Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, PA19122
- Institute of Computational Molecular Science, Temple University, Philadelphia, PA19122
| | - Stephan Alexander Pless
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen2100, Denmark
| | - Han Chow Chua
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen2100, Denmark
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Mizuno Y, Nakasone W, Nakamura M, Otaki JM. In Silico and In Vitro Evaluation of the Molecular Mimicry of the SARS-CoV-2 Spike Protein by Common Short Constituent Sequences (cSCSs) in the Human Proteome: Toward Safer Epitope Design for Vaccine Development. Vaccines (Basel) 2024; 12:539. [PMID: 38793790 PMCID: PMC11125730 DOI: 10.3390/vaccines12050539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2024] [Revised: 05/12/2024] [Accepted: 05/12/2024] [Indexed: 05/26/2024] Open
Abstract
Spike protein sequences in SARS-CoV-2 have been employed for vaccine epitopes, but many short constituent sequences (SCSs) in the spike protein are present in the human proteome, suggesting that some anti-spike antibodies induced by infection or vaccination may be autoantibodies against human proteins. To evaluate this possibility of "molecular mimicry" in silico and in vitro, we exhaustively identified common SCSs (cSCSs) found both in spike and human proteins bioinformatically. The commonality of SCSs between the two systems seemed to be coincidental, and only some cSCSs were likely to be relevant to potential self-epitopes based on three-dimensional information. Among three antibodies raised against cSCS-containing spike peptides, only the antibody against EPLDVL showed high affinity for the spike protein and reacted with an EPLDVL-containing peptide from the human unc-80 homolog protein. Western blot analysis revealed that this antibody also reacted with several human proteins expressed mainly in the small intestine, ovary, and stomach. Taken together, these results showed that most cSCSs are likely incapable of inducing autoantibodies but that at least EPLDVL functions as a self-epitope, suggesting a serious possibility of infection-induced or vaccine-induced autoantibodies in humans. High-risk cSCSs, including EPLDVL, should be excluded from vaccine epitopes to prevent potential autoimmune disorders.
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Affiliation(s)
- Yuya Mizuno
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Senbaru, Nishihara 903-0213, Okinawa, Japan
| | - Wataru Nakasone
- Computer Science and Intelligent Systems Unit, Department of Engineering, Faculty of Engineering, University of the Ryukyus, Senbaru, Nishihara 903-0213, Okinawa, Japan
| | - Morikazu Nakamura
- Computer Science and Intelligent Systems Unit, Department of Engineering, Faculty of Engineering, University of the Ryukyus, Senbaru, Nishihara 903-0213, Okinawa, Japan
| | - Joji M. Otaki
- The BCPH Unit of Molecular Physiology, Department of Chemistry, Biology and Marine Science, Faculty of Science, University of the Ryukyus, Senbaru, Nishihara 903-0213, Okinawa, Japan
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Farrell S, Dates J, Ramirez N, Hausknecht-Buss H, Kolosov D. Voltage-gated ion channels are expressed in the Malpighian tubules and anal papillae of the yellow fever mosquito (Aedes aegypti), and may regulate ion transport during salt and water imbalance. J Exp Biol 2024; 227:jeb246486. [PMID: 38197515 PMCID: PMC10912814 DOI: 10.1242/jeb.246486] [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: 07/28/2023] [Accepted: 12/22/2023] [Indexed: 01/11/2024]
Abstract
Vectors of infectious disease include several species of Aedes mosquitoes. The life cycle of Aedes aegypti, the yellow fever mosquito, consists of a terrestrial adult and an aquatic larval life stage. Developing in coastal waters can expose larvae to fluctuating salinity, causing salt and water imbalance, which is addressed by two prime osmoregulatory organs - the Malpighian tubules (MTs) and anal papillae (AP). Voltage-gated ion channels (VGICs) have recently been implicated in the regulation of ion transport in the osmoregulatory epithelia of insects. In the current study, we: (i) generated MT transcriptomes of freshwater-acclimated and brackish water-exposed larvae of Ae. aegypti, (ii) detected expression of several voltage-gated Ca2+, K+, Na+ and non-ion-selective ion channels in the MTs and AP using transcriptomics, PCR and gel electrophoresis, (iii) demonstrated that mRNA abundance of many altered significantly following brackish water exposure, and (iv) immunolocalized CaV1, NALCN, TRP/Painless and KCNH8 in the MTs and AP of larvae using custom-made antibodies. We found CaV1 to be expressed in the apical membrane of MTs of both larvae and adults, and its inhibition to alter membrane potentials of this osmoregulatory epithelium. Our data demonstrate that multiple VGICs are expressed in osmoregulatory epithelia of Ae. aegypti and may play an important role in the autonomous regulation of ion transport.
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Affiliation(s)
- Serena Farrell
- Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Road, San Marcos, CA 92096, USA
| | - Jocelyne Dates
- Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Road, San Marcos, CA 92096, USA
| | - Nancy Ramirez
- Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Road, San Marcos, CA 92096, USA
| | - Hannah Hausknecht-Buss
- Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Road, San Marcos, CA 92096, USA
| | - Dennis Kolosov
- Department of Biological Sciences, California State University San Marcos, 333 S. Twin Oaks Valley Road, San Marcos, CA 92096, USA
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Lory P. The good company of T-type calcium channels : Commentary on: "T-type calcium channelosome," a review by N. Weiss and G. W. Zamponi. Pflugers Arch 2024; 476:149-150. [PMID: 38191755 DOI: 10.1007/s00424-023-02903-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 12/21/2023] [Accepted: 12/28/2023] [Indexed: 01/10/2024]
Affiliation(s)
- Philippe Lory
- IGF, Univ Montpellier, CNRS, INSERM, Montpellier, France.
- LabEx 'Ion Channel Science and Therapeutics', Montpellier, France.
- Institut de Génomique Fonctionnelle - CNRS, 141 rue de la Cardonille, 34094, Montpellier, France.
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Schott K, Usher SG, Serra O, Carnevale V, Pless SA, Chua HC. Unplugging lateral fenestrations of NALCN reveals a hidden drug binding site within the pore module. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.04.12.536537. [PMID: 38328210 PMCID: PMC10849497 DOI: 10.1101/2023.04.12.536537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
The sodium (Na + ) leak channel (NALCN) is a member of the four-domain voltage-gated cation channel family that includes the prototypical voltage-gated sodium and calcium channels (Na V s and Ca V s, respectively). Unlike Na V s and Ca V s, which have four lateral fenestrations that serve as routes for lipophilic compounds to enter the central cavity to modulate channel function, NALCN has bulky residues (W311, L588, M1145 and Y1436) that block these openings. Structural data suggest that oc-cluded lateral fenestrations underlie the pharmacological resistance of NALCN to lipophilic compounds, but functional evidence is lacking. To test this hypothesis, we unplugged the fenestrations of NALCN by substituting the four aforementioned resi-dues with alanine (AAAA) and compared the effects of Na V , Ca V and NALCN block-ers on both wild-type (WT) and AAAA channels. Most compounds behaved in a simi-lar manner on both channels, but phenytoin and 2-aminoethoxydiphenyl borate (2-APB) elicited additional, distinct responses on AAAA channels. Further experiments using single alanine mutants revealed that phenytoin and 2-APB enter the inner cav-ity through distinct fenestrations, implying structural specificity to their modes of ac-cess. Using a combination of computational and functional approaches, we identified amino acid residues critical for 2-APB activity, supporting the existence of drug bind-ing site(s) within the pore region. Intrigued by the activity of 2-APB and its ana-logues, we tested additional compounds containing the diphenylmethane/amine moiety on WT channels. We identified compounds from existing clinically used drugs that exhibited diverse activity, thus expanding the pharmacological toolbox for NALCN. While the low potencies of active compounds reiterate the resistance of NALCN to pharmacological targeting, our findings lay the foundation for rational drug design to develop NALCN modulators with refined properties. Significance statement The sodium leak channel (NALCN) is essential for survival: mutations cause life-threatening developmental disorders in humans. However, no treatment is currently available due to the resistance of NALCN to pharmacological targeting. One likely reason is that the lateral fenestrations, a common route for clinically used drugs to enter and block related ion channels, are occluded in NALCN. Using a combination of computational and functional approaches, we unplugged the fenestrations of NALCN which led us to the first molecularly defined drug binding site within the pore region. Besides that, we also identified additional NALCN modulators from existing clinically used therapeutics, thus expanding the pharmacological toolbox for this leak channel.
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