1
|
De-la-Torre P, Wen H, Brower J, Martínez-Pérez K, Narui Y, Yeh F, Hale E, Ivanchenko MV, Corey DP, Sotomayor M, Indzhykulian AA. Elasticity and Thermal Stability are Key Determinants of Hearing Rescue by Mini-Protocadherin-15 Proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.16.599132. [PMID: 38948700 PMCID: PMC11212938 DOI: 10.1101/2024.06.16.599132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/02/2024]
Abstract
Protocadherin-15 is a core protein component of inner-ear hair-cell tip links pulling on transduction channels essential for hearing and balance. Protocadherin-15 defects can result in non-syndromic deafness or Usher syndrome type 1F (USH1F) with hearing loss, balance deficits, and progressive blindness. Three rationally engineered shortened versions of protocadherin-15 (mini-PCDH15s) amenable for gene therapy have been used to rescue function in USH1F mouse models. Two can successfully or partially rescue hearing, while another one fails. Here we show that despite varying levels of hearing rescue, all three mini-PCDH15 versions can rescue hair-cell mechanotransduction. Negative-stain electron microscopy shows that all three versions form dimers like the wild-type protein, while crystal structures of some engineered fragments show that these can properly fold and bind calcium ions essential for function. In contrast, simulations predict distinct elasticities and nano differential scanning fluorimetry shows differences in melting temperature measurements. Our data suggest that elasticity and thermal stability are key determinants of sustained hearing rescue by mini-PCDH15s.
Collapse
|
2
|
De-la-Torre P, Martínez-García C, Gratias P, Mun M, Santana P, Akyuz N, González W, Indzhykulian AA, Ramírez D. Identification of Druggable Binding Sites and Small Molecules as Modulators of TMC1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.05.583611. [PMID: 38826329 PMCID: PMC11142246 DOI: 10.1101/2024.03.05.583611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
Our ability to hear and maintain balance relies on the proper functioning of inner ear sensory hair cells, which translate mechanical stimuli into electrical signals via mechano-electrical transducer (MET) channels, composed of TMC1/2 proteins. However, the therapeutic use of ototoxic drugs, such as aminoglycosides and cisplatin, which can enter hair cells through MET channels, often leads to profound auditory and vestibular dysfunction. Despite extensive research on otoprotective compounds targeting MET channels, our understanding of how small molecule modulators interact with these channels remains limited, hampering the discovery of novel compounds. Here, we propose a structure-based screening approach, integrating 3D-pharmacophore modeling, molecular simulations, and experimental validation. Our pipeline successfully identified several novel compounds and FDA-approved drugs that reduced dye uptake in cultured cochlear explants, indicating MET modulation activity. Molecular docking and free-energy estimations for binding allowed us to identify three potential drug binding sites within the channel pore, phospholipids, and key amino acids involved in modulator interactions. We also identified shared ligand-binding features between TMC and structurally related TMEM16 protein families, providing novel insights into their distinct inhibition, while potentially guiding the rational design of MET-channel-specific modulators. Our pipeline offers a broad application to discover small molecule modulators for a wide spectrum of mechanosensitive ion channels.
Collapse
Affiliation(s)
- Pedro De-la-Torre
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Mass Eye and Ear, Boston, MA, USA
| | | | - Paul Gratias
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Mass Eye and Ear, Boston, MA, USA
| | - Matthew Mun
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Mass Eye and Ear, Boston, MA, USA
| | - Paula Santana
- Facultad de Ingeniería, Instituto de Ciencias Químicas Aplicadas, Universidad Autónoma de Chile, Santiago, Chile
| | - Nurunisa Akyuz
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Wendy González
- Center for Bioinformatics and Molecular Simulations (CBSM), University of Talca, Talca 3460000, Chile
| | - Artur A. Indzhykulian
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Mass Eye and Ear, Boston, MA, USA
| | - David Ramírez
- Department of Pharmacology, Faculty of Biological Sciences, University of Concepción, Chile
| |
Collapse
|
3
|
Tamilselvan E, Sotomayor M. CELSR1, a core planar cell polarity protein, features a weakly adhesive and flexible cadherin ectodomain. Structure 2024; 32:476-491.e5. [PMID: 38307021 DOI: 10.1016/j.str.2024.01.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 09/30/2023] [Accepted: 01/08/2024] [Indexed: 02/04/2024]
Abstract
Planar cell polarity (PCP), essential to multicellular developmental processes, arises when cells polarize and align across tissues. Central to PCP is CELSR1, an atypical cadherin featuring a long ectodomain with nine extracellular cadherin (EC) repeats, a membrane adjacent domain (MAD10), and several characteristic adhesion GPCR domains. Cell-based aggregation assays have demonstrated CELSR1's homophilic adhesive nature, but mechanistic details are missing. Here, we investigate the possible adhesive properties and structures of CELSR1 EC repeats. Our bead aggregation assays do not support strong adhesion by EC repeats alone. Consistently, EC1-4 only dimerizes at high concentration in solution. Crystal structures of human CELSR1 EC1-4 and EC4-7 reveal typical folds and a non-canonical linker between EC5 and EC6. Simulations and experiments using EC4-7 indicate flexibility at EC5-6, and solution experiments show EC7-MAD10-mediated dimerization. Our results suggest weak homophilic adhesion by CELSR1 cadherin repeats and provide mechanistic insights into the structural determinants of CELSR1 function.
Collapse
Affiliation(s)
- Elakkiya Tamilselvan
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; Biophysics Program, The Ohio State University, Columbus, OH 43210, USA
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; Biophysics Program, The Ohio State University, Columbus, OH 43210, USA.
| |
Collapse
|
4
|
Yun Y, Lee SY. Updates on Genetic Hearing Loss: From Diagnosis to Targeted Therapies. J Audiol Otol 2024; 28:88-92. [PMID: 38695053 PMCID: PMC11065549 DOI: 10.7874/jao.2024.00157] [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: 02/22/2024] [Revised: 03/21/2024] [Accepted: 04/04/2024] [Indexed: 05/05/2024] Open
Abstract
Sensorineural hearing loss (SNHL) is the most common sensory disorder, with a high Mendelian genetic contribution. Considering the genotypic and phenotypic heterogeneity of SNHL, the advent of next-generation sequencing technologies has revolutionized knowledge on its genomic architecture. Nonetheless, the conventional application of panel and exome sequencing in real-world practice is being challenged by the emerging need to explore the diagnostic capability of whole-genome sequencing, which enables the detection of both noncoding and structural variations. Small molecules and gene therapies represent good examples of how breakthroughs in genetic understanding can be translated into targeted therapies for SNHL. For example, targeted small molecules have been used to ameliorate autoinflammatory hearing loss caused by gain-of-function variants of NLRP3 and inner ear proteinopathy with OSBPL2 variants underlying dysfunctional autophagy. Strikingly, the successful outcomes of the first-in-human trial of OTOF gene therapy highlighted its potential in the treatment of various forms of genetic hearing loss. clustered regularly interspaced short palindromic repeats (CRISPR)-based technologies are currently being developed for site-specific genome editing to treat human genetic disorders. These advancements have led to an era of genotype- and mechanism-based precision medicine in SNHL practice.
Collapse
Affiliation(s)
- Yejin Yun
- Department of Otorhinolaryngology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
| | - Sang-Yeon Lee
- Department of Otorhinolaryngology, Seoul National University College of Medicine, Seoul National University Hospital, Seoul, Korea
- Department of Genomic Medicine, Seoul National University Hospital, Seoul, Korea
- Sensory Organ Research Institute, Seoul National University Medical Research Center, Seoul, Korea
| |
Collapse
|
5
|
Redfield SE, De-la-Torre P, Zamani M, Wang H, Khan H, Morris T, Shariati G, Karimi M, Kenna MA, Seo GH, Xu H, Lu W, Naz S, Galehdari H, Indzhykulian AA, Shearer AE, Vona B. PKHD1L1, a gene involved in the stereocilia coat, causes autosomal recessive nonsyndromic hearing loss. Hum Genet 2024; 143:311-329. [PMID: 38459354 PMCID: PMC11043200 DOI: 10.1007/s00439-024-02649-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 01/21/2024] [Indexed: 03/10/2024]
Abstract
Identification of genes associated with nonsyndromic hearing loss is a crucial endeavor given the substantial number of individuals who remain without a diagnosis after even the most advanced genetic testing. PKHD1L1 was established as necessary for the formation of the cochlear hair-cell stereociliary coat and causes hearing loss in mice and zebrafish when mutated. We sought to determine if biallelic variants in PKHD1L1 also cause hearing loss in humans. Exome sequencing was performed on DNA of four families segregating autosomal recessive nonsyndromic sensorineural hearing loss. Compound heterozygous p.[(Gly129Ser)];p.[(Gly1314Val)] and p.[(Gly605Arg)];p[(Leu2818TyrfsTer5)], homozygous missense p.(His2479Gln) and nonsense p.(Arg3381Ter) variants were identified in PKHD1L1 that were predicted to be damaging using in silico pathogenicity prediction methods. In vitro functional analysis of two missense variants was performed using purified recombinant PKHD1L1 protein fragments. We then evaluated protein thermodynamic stability with and without the missense variants found in one of the families and performed a minigene splicing assay for another variant. In silico molecular modeling using AlphaFold2 and protein sequence alignment analysis were carried out to further explore potential variant effects on structure. In vitro functional assessment indicated that both engineered PKHD1L1 p.(Gly129Ser) and p.(Gly1314Val) mutant constructs significantly reduced the folding and structural stabilities of the expressed protein fragments, providing further evidence to support pathogenicity of these variants. Minigene assay of the c.1813G>A p.(Gly605Arg) variant, located at the boundary of exon 17, revealed exon skipping leading to an in-frame deletion of 48 amino acids. In silico molecular modeling exposed key structural features that might suggest PKHD1L1 protein destabilization. Multiple lines of evidence collectively associate PKHD1L1 with nonsyndromic mild-moderate to severe sensorineural hearing loss. PKHD1L1 testing in individuals with mild-moderate hearing loss may identify further affected families.
Collapse
Affiliation(s)
- Shelby E Redfield
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, 300 Longwood Avenue, BCH-3129, Boston, MA, 02115, USA
| | - Pedro De-la-Torre
- Mass Eye and Ear, Eaton Peabody Laboratories, Boston, MA, USA
- Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA
| | - Mina Zamani
- Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
- Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
| | - Hanjun Wang
- Precision Medicine Center, Academy of Medical Science, Zhengzhou University, No. 40 Daxuebei Road, Zhengzhou, 450052, China
| | - Hina Khan
- School of Biological Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore, 54590, Pakistan
| | - Tyler Morris
- Mass Eye and Ear, Eaton Peabody Laboratories, Boston, MA, USA
| | - Gholamreza Shariati
- Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
- Department of Medical Genetics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Majid Karimi
- Khuzestan Cochlear Implantation Center (Tabassom), Ahvaz, Iran
| | - Margaret A Kenna
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, 300 Longwood Avenue, BCH-3129, Boston, MA, 02115, USA
- Mass Eye and Ear, Eaton Peabody Laboratories, Boston, MA, USA
| | | | - Hongen Xu
- Precision Medicine Center, Academy of Medical Science, Zhengzhou University, No. 40 Daxuebei Road, Zhengzhou, 450052, China
| | - Wei Lu
- Department of Otorhinolaryngology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jian-She Road, Zhengzhou, 450052, China
| | - Sadaf Naz
- School of Biological Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore, 54590, Pakistan
| | - Hamid Galehdari
- Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Artur A Indzhykulian
- Mass Eye and Ear, Eaton Peabody Laboratories, Boston, MA, USA.
- Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA.
| | - A Eliot Shearer
- Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, 300 Longwood Avenue, BCH-3129, Boston, MA, 02115, USA.
- Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, 25 Shattuck Street, Boston, MA, 02115, USA.
| | - Barbara Vona
- Institute of Human Genetics, University Medical Center Göttingen, 37073, Göttingen, Germany.
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075, Göttingen, Germany.
| |
Collapse
|
6
|
Arora N, Hazra JP, Roy S, Bhati GK, Gupta S, Yogendran KP, Chaudhuri A, Sagar A, Rakshit S. Emergence of slip-ideal-slip behavior in tip-links serve as force filters of sound in hearing. Nat Commun 2024; 15:1595. [PMID: 38383683 PMCID: PMC10881517 DOI: 10.1038/s41467-024-45423-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Accepted: 01/23/2024] [Indexed: 02/23/2024] Open
Abstract
Tip-links in the inner ear convey force from sound and trigger mechanotransduction. Here, we present evidence that tip-links (collectively as heterotetrameric complexes of cadherins) function as force filters during mechanotransduction. Our force-clamp experiments reveal that the tip-link complexes show slip-ideal-slip bond dynamics. At low forces, the lifetime of the tip-link complex drops monotonically, indicating slip-bond dynamics. The ideal bond, rare in nature, is seen in an intermediate force regime where the survival of the complex remains constant over a wide range. At large forces, tip-links follow a slip bond and dissociate entirely to cut-off force transmission. In contrast, the individual tip-links (heterodimers) display slip-catch-slip bonds to the applied forces. While with a phenotypic mutant, we showed the importance of the slip-catch-slip bonds in uninterrupted hearing, our coarse-grained Langevin dynamics simulations demonstrated that the slip-ideal-slip bonds emerge as a collective feature from the slip-catch-slip bonds of individual tip-links.
Collapse
Affiliation(s)
- Nisha Arora
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Jagadish P Hazra
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Sandip Roy
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Gaurav K Bhati
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Sarika Gupta
- National Institute of Immunology, New Delhi, India
| | - K P Yogendran
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Abhishek Chaudhuri
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India.
| | - Amin Sagar
- Centre de Biologie Structurale, INSERM, CNRS, Université de Montpellier, Montpellier, France.
| | - Sabyasachi Rakshit
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India.
| |
Collapse
|
7
|
Redfield SE, De-la-Torre P, Zamani M, Wang H, Khan H, Morris T, Shariati G, Karimi M, Kenna MA, Seo GH, Xu H, Lu W, Naz S, Galehdari H, Indzhykulian AA, Shearer AE, Vona B. PKHD1L1, A Gene Involved in the Stereocilia Coat, Causes Autosomal Recessive Nonsyndromic Hearing Loss. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.10.08.23296081. [PMID: 37873491 PMCID: PMC10593026 DOI: 10.1101/2023.10.08.23296081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Identification of genes associated with nonsyndromic hearing loss is a crucial endeavor given the substantial number of individuals who remain without a diagnosis after even the most advanced genetic testing. PKHD1L1 was established as necessary for the formation of the cochlear hair-cell stereociliary coat and causes hearing loss in mice and zebrafish when mutated. We sought to determine if biallelic variants in PKHD1L1 also cause hearing loss in humans. Exome sequencing was performed on DNA of four families segregating autosomal recessive nonsyndromic sensorineural hearing loss. Compound heterozygous p.[(Gly129Ser)];p.[(Gly1314Val)] and p.[(Gly605Arg)];p[(Leu2818TyrfsTer5)], homozygous missense p.(His2479Gln) and nonsense p.(Arg3381Ter) variants were identified in PKHD1L1 that were predicted to be damaging using in silico pathogenicity prediction methods. In vitro functional analysis of two missense variants was performed using purified recombinant PKHD1L1 protein fragments. We then evaluated protein thermodynamic stability with and without the missense variants found in one of the families and performed a minigene splicing assay for another variant. In silico molecular modelling using AlphaFold2 and protein sequence alignment analysis were carried out to further explore potential variant effects on structure. In vitro functional assessment indicated that both engineered PKHD1L1 p.(Gly129Ser) and p.(Gly1314Val) mutant constructs significantly reduced the folding and structural stabilities of the expressed protein fragments, providing further evidence to support pathogenicity of these variants. Minigene assay of the c.1813G>A p.(Gly605Arg) variant, located at the boundary of exon 17, revealed exon skipping leading to an in-frame deletion of 48 amino acids. In silico molecular modelling exposed key structural features that might suggest PKHD1L1 protein destabilization. Multiple lines of evidence collectively associate PKHD1L1 with nonsyndromic mild-moderate to severe sensorineural hearing loss. PKHD1L1 testing in individuals with mild-moderate hearing loss may identify further affected families.
Collapse
Affiliation(s)
- Shelby E. Redfield
- Department of Otolaryngology and Communication Enhancement, Boston Children’s Hospital, 300 Longwood Avenue, BCH-3129, Boston, MA 02115, USA
| | - Pedro De-la-Torre
- Mass Eye and Ear, Eaton Peabody Laboratories, Boston, Massachusetts, USA
- Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Mina Zamani
- Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
- Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
| | - Hanjun Wang
- Precision Medicine Center, Academy of Medical Science, Zhengzhou University, No. 40 Daxuebei Road, Zhengzhou, 450052, China
| | - Hina Khan
- School of Biological Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore 54590, Pakistan
| | - Tyler Morris
- Mass Eye and Ear, Eaton Peabody Laboratories, Boston, Massachusetts, USA
| | - Gholamreza Shariati
- Narges Medical Genetics and Prenatal Diagnosis Laboratory, Kianpars, Ahvaz, Iran
- Department of Medical Genetics, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran
| | - Majid Karimi
- Khuzestan Cochlear Implantation Center (Tabassom), Ahvaz, Iran
| | - Margaret A. Kenna
- Department of Otolaryngology and Communication Enhancement, Boston Children’s Hospital, 300 Longwood Avenue, BCH-3129, Boston, MA 02115, USA
- Mass Eye and Ear, Eaton Peabody Laboratories, Boston, Massachusetts, USA
| | | | - Hongen Xu
- Precision Medicine Center, Academy of Medical Science, Zhengzhou University, No. 40 Daxuebei Road, Zhengzhou, 450052, China
| | - Wei Lu
- Department of Otorhinolaryngology, The First Affiliated Hospital of Zhengzhou University, No. 1 Jian-she Road, Zhengzhou, 450052, China
| | - Sadaf Naz
- School of Biological Sciences, University of the Punjab, Quaid-e-Azam Campus, Lahore 54590, Pakistan
| | - Hamid Galehdari
- Department of Biology, Faculty of Science, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Artur A. Indzhykulian
- Mass Eye and Ear, Eaton Peabody Laboratories, Boston, Massachusetts, USA
- Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - A. Eliot Shearer
- Department of Otolaryngology and Communication Enhancement, Boston Children’s Hospital, 300 Longwood Avenue, BCH-3129, Boston, MA 02115, USA
- Department of Otolaryngology Head and Neck Surgery, Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA
| | - Barbara Vona
- Institute of Human Genetics, University Medical Center Göttingen, 37073 Göttingen, Germany
- Institute for Auditory Neuroscience and InnerEarLab, University Medical Center Göttingen, 37075 Göttingen, Germany
| |
Collapse
|
8
|
Ivanchenko MV, Hathaway DM, Mulhall EM, Booth KT, Wang M, Peters CW, Klein AJ, Chen X, Li Y, György B, Corey DP. PCDH15 Dual-AAV Gene Therapy for Deafness and Blindness in Usher Syndrome Type 1F. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.09.566447. [PMID: 38014037 PMCID: PMC10680673 DOI: 10.1101/2023.11.09.566447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Usher syndrome type 1F (USH1F), resulting from mutations in the protocadherin-15 (PCDH15) gene, is characterized by congenital lack of hearing and balance, and progressive blindness in the form of retinitis pigmentosa. In this study, we explore a novel approach for USH1F gene therapy, exceeding the single AAV packaging limit by employing a dual adeno-associated virus (AAV) strategy to deliver the full-length PCDH15 coding sequence. We demonstrate the efficacy of this strategy in mouse USH1F models, effectively restoring hearing and balance in these mice. Importantly, our approach also proves successful in expressing PCDH15 in clinically relevant retinal models, including human retinal organoids and non-human primate retina, showing efficient targeting of photoreceptors and proper protein expression in the calyceal processes. This research represents a major step toward advancing gene therapy for USH1F and the multiple challenges of hearing, balance, and vision impairment.
Collapse
|
9
|
Zhang N, Häring M, Wolf F, Großhans J, Kong D. Dynamics and functions of E-cadherin complexes in epithelial cell and tissue morphogenesis. MARINE LIFE SCIENCE & TECHNOLOGY 2023; 5:585-601. [PMID: 38045551 PMCID: PMC10689684 DOI: 10.1007/s42995-023-00206-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 10/31/2023] [Indexed: 12/05/2023]
Abstract
Cell-cell adhesion is at the center of structure and dynamics of epithelial tissue. E-cadherin-catenin complexes mediate Ca2+-dependent trans-homodimerization and constitute the kernel of adherens junctions. Beyond the basic function of cell-cell adhesion, recent progress sheds light the dynamics and interwind interactions of individual E-cadherin-catenin complex with E-cadherin superclusters, contractile actomyosin and mechanics of the cortex and adhesion. The nanoscale architecture of E-cadherin complexes together with cis-interactions and interactions with cortical actomyosin adjust to junctional tension and mechano-transduction by reinforcement or weakening of specific features of the interactions. Although post-translational modifications such as phosphorylation and glycosylation have been implicated, their role for specific aspects of in E-cadherin function has remained unclear. Here, we provide an overview of the E-cadherin complex in epithelial cell and tissue morphogenesis focusing on nanoscale architectures by super-resolution approaches and post-translational modifications from recent, in particular in vivo, studies. Furthermore, we review the computational modelling in E-cadherin complexes and highlight how computational modelling has contributed to a deeper understanding of the E-cadherin complexes.
Collapse
Affiliation(s)
- Na Zhang
- Department of Biology, Philipps University, 35043 Marburg, Germany
| | - Matthias Häring
- Göttingen Campus Institute for Dynamics of Biological Networks (CIDBN), Georg August University Göttingen, 37073 Göttingen, Germany
| | - Fred Wolf
- Göttingen Campus Institute for Dynamics of Biological Networks (CIDBN), Georg August University Göttingen, 37073 Göttingen, Germany
| | - Jörg Großhans
- Department of Biology, Philipps University, 35043 Marburg, Germany
- Göttingen Campus Institute for Dynamics of Biological Networks (CIDBN), Georg August University Göttingen, 37073 Göttingen, Germany
| | - Deqing Kong
- Department of Biology, Philipps University, 35043 Marburg, Germany
- Göttingen Campus Institute for Dynamics of Biological Networks (CIDBN), Georg August University Göttingen, 37073 Göttingen, Germany
| |
Collapse
|
10
|
Villasante CM, Deng X, Cohen JE, Hudspeth AJ. Nanomechanics of wild-type and mutant dimers of the tip-link protein protocadherin 15. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.17.562769. [PMID: 37905108 PMCID: PMC10614884 DOI: 10.1101/2023.10.17.562769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
Mechanical force controls the opening and closing of mechanosensitive ion channels atop the hair bundles of the inner ear. The filamentous tip link connecting transduction channels to the tallest neighboring stereocilium modulates the force transmitted to the channels and thus changes their probability of opening. Each tip link comprises four molecules: a dimer of protocadherin 15 and a dimer of cadherin 23, all of which are stabilized by Ca2+ binding. Using a high-speed optical trap to examine dimeric PCDH15, we find that the protein's configuration is sensitive to Ca2+ and that the molecule exhibits limited unfolding at a physiological Ca2+ concentration. PCDH15 can therefore modulate its stiffness without undergoing large unfolding events in physiological Ca2+ conditions. The experimentally determined stiffness of PCDH15 accords with published values for the stiffness of the gating spring, the mechanical element that controls the opening of mechanotransduction channels. When PCDH15 has a point mutation, V507D, associated with non-syndromic hearing loss, unfolding events occur more frequently under tension and refolding events occur less often than in the wild-type protein. Our results suggest that the maintenance of appropriate tension in the gating spring is critical to the appropriate transmission of force to transduction channels, and hence to hearing.
Collapse
Affiliation(s)
- Camila M Villasante
- Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065 USA
| | - Xinyue Deng
- Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065 USA
| | - Joel E Cohen
- Laboratory of Populations, The Rockefeller University, New York, NY 10065 USA
- Earth Institute and Department of Statistics, Columbia University, New York, NY 10027 USA
- Department of Statistics, University of Chicago, Chicago, IL 60637 USA
| | - A J Hudspeth
- Laboratory of Sensory Neuroscience, The Rockefeller University, New York, NY 10065 USA
- Howard Hughes Medical Institute, The Rockefeller University, New York, NY 10065 USA
| |
Collapse
|
11
|
Kaur V, Ghosh SK, Bhatia T, Rakshit S. Redefining the Structure of Tip Links in Hair Cells. Biochemistry 2023. [PMID: 37399091 DOI: 10.1021/acs.biochem.3c00161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2023]
Abstract
Tip links are seen under microscopes as double-helical tetrameric complexes of long nonclassical cadherins, cadherin-23 and protocadherin-15. The twisted filamentous structure enables tip links to regulate mechanotransduction in hearing and balance. While the molecular details of the double-helical protocadherin-15 cis dimers have been deciphered, a similar conformation of cadherin-23 is still elusive. In a search of cadherin-23 cis dimers, we performed photoinduced cross-linking of unmodified proteins in solution and on lipid membranes and observed no trace of cadherin-23 cis dimers. Reportedly, tip links are dynamic connections, assembling and disassembling in seconds. Using lipid vesicles, we measured significantly slower aggregations between cis dimers of tip link cadherins than via dimer-monomer interactions, indicating that the trans interactions between two cis dimers may possess steric restraints and defer reassociations. Reconnections of tip links are thus kinetically most desired between protocadherin-15 cis dimers and cadherin-23 monomers. Here we propose that the helical geometry of tip links is induced by protocadherin-15 cis dimers, while cadherin-23 remains single before tip linking.
Collapse
Affiliation(s)
- Veerpal Kaur
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Mohali 140306, Punjab, India
| | - Sanat K Ghosh
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Mohali 140306, Punjab, India
| | - Tripta Bhatia
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Mohali 140306, Punjab, India
| | - Sabyasachi Rakshit
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Mohali 140306, Punjab, India
| |
Collapse
|
12
|
Ivanchenko MV, Hathaway DM, Klein AJ, Pan B, Strelkova O, De-la-Torre P, Wu X, Peters CW, Mulhall EM, Booth KT, Goldstein C, Brower J, Sotomayor M, Indzhykulian AA, Corey DP. Mini-PCDH15 gene therapy rescues hearing in a mouse model of Usher syndrome type 1F. Nat Commun 2023; 14:2400. [PMID: 37100771 PMCID: PMC10133396 DOI: 10.1038/s41467-023-38038-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 04/11/2023] [Indexed: 04/28/2023] Open
Abstract
Usher syndrome type 1 F (USH1F), caused by mutations in the protocadherin-15 gene (PCDH15), is characterized by congenital deafness, lack of balance, and progressive blindness. In hair cells, the receptor cells of the inner ear, PCDH15 is a component of tip links, fine filaments which pull open mechanosensory transduction channels. A simple gene addition therapy for USH1F is challenging because the PCDH15 coding sequence is too large for adeno-associated virus (AAV) vectors. We use rational, structure-based design to engineer mini-PCDH15s in which 3-5 of the 11 extracellular cadherin repeats are deleted, but which still bind a partner protein. Some mini-PCDH15s can fit in an AAV. An AAV encoding one of these, injected into the inner ears of mouse models of USH1F, produces a mini-PCDH15 which properly forms tip links, prevents the degeneration of hair cell bundles, and rescues hearing. Mini-PCDH15s may be a useful therapy for the deafness of USH1F.
Collapse
Affiliation(s)
| | - Daniel M Hathaway
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Massachusetts Eye and Ear, Boston, MA, USA
| | - Alex J Klein
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Bifeng Pan
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Olga Strelkova
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Massachusetts Eye and Ear, Boston, MA, USA
| | - Pedro De-la-Torre
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Massachusetts Eye and Ear, Boston, MA, USA
| | - Xudong Wu
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Cole W Peters
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Eric M Mulhall
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Kevin T Booth
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Corey Goldstein
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Joseph Brower
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Massachusetts Eye and Ear, Boston, MA, USA
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Artur A Indzhykulian
- Department of Otolaryngology - Head and Neck Surgery, Harvard Medical School and Massachusetts Eye and Ear, Boston, MA, USA
| | - David P Corey
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
13
|
Krey JF, Chatterjee P, Halford J, Cunningham CL, Perrin BJ, Barr-Gillespie PG. Control of stereocilia length during development of hair bundles. PLoS Biol 2023; 21:e3001964. [PMID: 37011103 PMCID: PMC10101650 DOI: 10.1371/journal.pbio.3001964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 04/13/2023] [Accepted: 03/14/2023] [Indexed: 04/05/2023] Open
Abstract
Assembly of the hair bundle, the sensory organelle of the inner ear, depends on differential growth of actin-based stereocilia. Separate rows of stereocilia, labeled 1 through 3 from tallest to shortest, lengthen or shorten during discrete time intervals during development. We used lattice structured illumination microscopy and surface rendering to measure dimensions of stereocilia from mouse apical inner hair cells during early postnatal development; these measurements revealed a sharp transition at postnatal day 8 between stage III (row 1 and 2 widening; row 2 shortening) and stage IV (final row 1 lengthening and widening). Tip proteins that determine row 1 lengthening did not accumulate simultaneously during stages III and IV; while the actin-bundling protein EPS8 peaked at the end of stage III, GNAI3 peaked several days later-in early stage IV-and GPSM2 peaked near the end of stage IV. To establish the contributions of key macromolecular assemblies to bundle structure, we examined mouse mutants that eliminated tip links (Cdh23v2J or Pcdh15av3J), transduction channels (TmieKO), or the row 1 tip complex (Myo15ash2). Cdh23v2J/v2J and Pcdh15av3J/av3J bundles had adjacent stereocilia in the same row that were not matched in length, revealing that a major role of these cadherins is to synchronize lengths of side-by-side stereocilia. Use of the tip-link mutants also allowed us to distinguish the role of transduction from effects of transduction proteins themselves. While levels of GNAI3 and GPSM2, which stimulate stereocilia elongation, were greatly attenuated at the tips of TmieKO/KO row 1 stereocilia, they accumulated normally in Cdh23v2J/v2J and Pcdh15av3J/av3J stereocilia. These results reinforced the suggestion that the transduction proteins themselves facilitate localization of proteins in the row 1 complex. By contrast, EPS8 concentrates at tips of all TmieKO/KO, Cdh23v2J/v2J, and Pcdh15av3J/av3J stereocilia, correlating with the less polarized distribution of stereocilia lengths in these bundles. These latter results indicated that in wild-type hair cells, the transduction complex prevents accumulation of EPS8 at the tips of shorter stereocilia, causing them to shrink (rows 2 and 3) or disappear (row 4 and microvilli). Reduced rhodamine-actin labeling at row 2 stereocilia tips of tip-link and transduction mutants suggests that transduction's role is to destabilize actin filaments there. These results suggest that regulation of stereocilia length occurs through EPS8 and that CDH23 and PCDH15 regulate stereocilia lengthening beyond their role in gating mechanotransduction channels.
Collapse
Affiliation(s)
- Jocelyn F. Krey
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Paroma Chatterjee
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Julia Halford
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Christopher L. Cunningham
- Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States of America
| | - Benjamin J. Perrin
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, Indiana, United States of America
| | - Peter G. Barr-Gillespie
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science University, Portland, Oregon, United States of America
| |
Collapse
|
14
|
Srinivas CS, Singaraju GS, Kaur V, Das S, Ghosh SK, Sagar A, Kumar A, Bhatia T, Rakshit S. Transient interactions drive the lateral clustering of cadherin-23 on membrane. Commun Biol 2023; 6:293. [PMID: 36934176 PMCID: PMC10024700 DOI: 10.1038/s42003-023-04677-6] [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: 09/21/2022] [Accepted: 03/07/2023] [Indexed: 03/20/2023] Open
Abstract
Cis and trans-interactions among cadherins secure multicellularity. While the molecular structure of trans-interactions of cadherins is well understood, work to identify the molecular cues that spread the cis-interactions two-dimensionally is still ongoing. Here, we report that transient, weak, yet multivalent, and spatially distributed hydrophobic interactions that are involved in liquid-liquid phase separations of biomolecules in solution, alone can drive the lateral-clustering of cadherin-23 on a membrane. No specific cis-dimer interactions are required for the lateral clustering. In cells, the cis-clustering accelerates cell-cell adhesion and, thus, contributes to cell-adhesion kinetics along with strengthening the junction. Although the physiological connection of cis-clustering with rapid adhesion is yet to be explored, we speculate that the over-expression of cadherin-23 in M2-macrophages may facilitate faster attachments to circulatory tumor cells during metastasis.
Collapse
Affiliation(s)
- Cheerneni S Srinivas
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Gayathri S Singaraju
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Veerpal Kaur
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Sayan Das
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Sanat K Ghosh
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Amin Sagar
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Anuj Kumar
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
- Centre for Protein Science Design and Engineering, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Tripta Bhatia
- Department of Physical Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India
| | - Sabyasachi Rakshit
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India.
- Centre for Protein Science Design and Engineering, Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India.
| |
Collapse
|
15
|
Han H, McGivney BA, Allen L, Bai D, Corduff LR, Davaakhuu G, Davaasambuu J, Dorjgotov D, Hall TJ, Hemmings AJ, Holtby AR, Jambal T, Jargalsaikhan B, Jargalsaikhan U, Kadri NK, MacHugh DE, Pausch H, Readhead C, Warburton D, Dugarjaviin M, Hill EW. Common protein-coding variants influence the racing phenotype in galloping racehorse breeds. Commun Biol 2022; 5:1320. [PMID: 36513809 PMCID: PMC9748125 DOI: 10.1038/s42003-022-04206-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Accepted: 11/01/2022] [Indexed: 12/14/2022] Open
Abstract
Selection for system-wide morphological, physiological, and metabolic adaptations has led to extreme athletic phenotypes among geographically diverse horse breeds. Here, we identify genes contributing to exercise adaptation in racehorses by applying genomics approaches for racing performance, an end-point athletic phenotype. Using an integrative genomics strategy to first combine population genomics results with skeletal muscle exercise and training transcriptomic data, followed by whole-genome resequencing of Asian horses, we identify protein-coding variants in genes of interest in galloping racehorse breeds (Arabian, Mongolian and Thoroughbred). A core set of genes, G6PC2, HDAC9, KTN1, MYLK2, NTM, SLC16A1 and SYNDIG1, with central roles in muscle, metabolism, and neurobiology, are key drivers of the racing phenotype. Although racing potential is a multifactorial trait, the genomic architecture shaping the common athletic phenotype in horse populations bred for racing provides evidence for the influence of protein-coding variants in fundamental exercise-relevant genes. Variation in these genes may therefore be exploited for genetic improvement of horse populations towards specific types of racing.
Collapse
Affiliation(s)
- Haige Han
- grid.411638.90000 0004 1756 9607Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, College of Animal Science, Equine Research Center, Inner Mongolia Agricultural University, Hohhot, 010018 China
| | - Beatrice A. McGivney
- grid.496984.ePlusvital Ltd, The Highline, Dun Laoghaire Business Park, Dublin, A96 W5T3 Ireland
| | - Lucy Allen
- grid.417905.e0000 0001 2186 5933Royal Agricultural University, Cirencester, Gloucestershire GL7 6JS UK
| | - Dongyi Bai
- grid.411638.90000 0004 1756 9607Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, College of Animal Science, Equine Research Center, Inner Mongolia Agricultural University, Hohhot, 010018 China
| | - Leanne R. Corduff
- grid.496984.ePlusvital Ltd, The Highline, Dun Laoghaire Business Park, Dublin, A96 W5T3 Ireland
| | - Gantulga Davaakhuu
- grid.425564.40000 0004 0587 3863Institute of Biology, Mongolian Academy of Sciences, Peace Avenue 54B, Ulaanbaatar, 13330 Mongolia
| | - Jargalsaikhan Davaasambuu
- Ajnai Sharga Horse Racing Team, Encanto Town 210-11, Ikh Mongol State Street, 26th Khoroo, Bayanzurkh district Ulaanbaatar, 13312 Mongolia
| | - Dulguun Dorjgotov
- grid.440461.30000 0001 2191 7895School of Industrial Technology, Mongolian University of Science and Technology, Ulaanbaatar, 661 Mongolia
| | - Thomas J. Hall
- grid.7886.10000 0001 0768 2743UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin D04 V1W8 Ireland
| | - Andrew J. Hemmings
- grid.417905.e0000 0001 2186 5933Royal Agricultural University, Cirencester, Gloucestershire GL7 6JS UK
| | - Amy R. Holtby
- grid.496984.ePlusvital Ltd, The Highline, Dun Laoghaire Business Park, Dublin, A96 W5T3 Ireland
| | - Tuyatsetseg Jambal
- grid.440461.30000 0001 2191 7895School of Industrial Technology, Mongolian University of Science and Technology, Ulaanbaatar, 661 Mongolia
| | - Badarch Jargalsaikhan
- grid.444534.60000 0000 8485 883XDepartment of Obstetrics and Gynecology, Mongolian National University of Medical Sciences, Ulaanbaatar, 14210 Mongolia
| | - Uyasakh Jargalsaikhan
- Ajnai Sharga Horse Racing Team, Encanto Town 210-11, Ikh Mongol State Street, 26th Khoroo, Bayanzurkh district Ulaanbaatar, 13312 Mongolia
| | - Naveen K. Kadri
- grid.5801.c0000 0001 2156 2780Animal Genomics, Institute of Agricultural Sciences, ETH Zürich, Universitätstrasse 2, 8092 Zürich, Switzerland
| | - David E. MacHugh
- grid.7886.10000 0001 0768 2743UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin D04 V1W8 Ireland ,grid.7886.10000 0001 0768 2743UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin D04 V1W8 Ireland
| | - Hubert Pausch
- grid.5801.c0000 0001 2156 2780Animal Genomics, Institute of Agricultural Sciences, ETH Zürich, Universitätstrasse 2, 8092 Zürich, Switzerland
| | - Carol Readhead
- grid.20861.3d0000000107068890Biology and Bioengineering, California Institute of Technology, Pasadena, CA 91125 USA
| | - David Warburton
- grid.42505.360000 0001 2156 6853The Saban Research Institute, Children’s Hospital Los Angeles, Keck School of Medicine, University of Southern California, Los Angeles, CA 90027 USA
| | - Manglai Dugarjaviin
- grid.411638.90000 0004 1756 9607Inner Mongolia Key Laboratory of Equine Genetics, Breeding and Reproduction, College of Animal Science, Equine Research Center, Inner Mongolia Agricultural University, Hohhot, 010018 China
| | - Emmeline W. Hill
- grid.496984.ePlusvital Ltd, The Highline, Dun Laoghaire Business Park, Dublin, A96 W5T3 Ireland ,grid.7886.10000 0001 0768 2743UCD School of Agriculture and Food Science, University College Dublin, Belfield, Dublin D04 V1W8 Ireland
| |
Collapse
|
16
|
Qiu X, Müller U. Sensing sound: Cellular specializations and molecular force sensors. Neuron 2022; 110:3667-3687. [PMID: 36223766 PMCID: PMC9671866 DOI: 10.1016/j.neuron.2022.09.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 08/03/2022] [Accepted: 09/14/2022] [Indexed: 11/08/2022]
Abstract
Organisms of all phyla express mechanosensitive ion channels with a wide range of physiological functions. In recent years, several classes of mechanically gated ion channels have been identified. Some of these ion channels are intrinsically mechanosensitive. Others depend on accessory proteins to regulate their response to mechanical force. The mechanotransduction machinery of cochlear hair cells provides a particularly striking example of a complex force-sensing machine. This molecular ensemble is embedded into a specialized cellular compartment that is crucial for its function. Notably, mechanotransduction channels of cochlear hair cells are not only critical for auditory perception. They also shape their cellular environment and regulate the development of auditory circuitry. Here, we summarize recent discoveries that have shed light on the composition of the mechanotransduction machinery of cochlear hair cells and how this machinery contributes to the development and function of the auditory system.
Collapse
Affiliation(s)
- Xufeng Qiu
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Ulrich Müller
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| |
Collapse
|
17
|
Qian F, Wei G, Gao Y, Wang X, Gong J, Guo C, Wang X, Zhang X, Zhao J, Wang C, Xu M, Hu Y, Yin G, Kang J, Chai R, Xie G, Liu D. Single-cell RNA-sequencing of zebrafish hair cells reveals novel genes potentially involved in hearing loss. Cell Mol Life Sci 2022; 79:385. [PMID: 35753015 PMCID: PMC11072488 DOI: 10.1007/s00018-022-04410-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 05/18/2022] [Accepted: 06/01/2022] [Indexed: 01/22/2023]
Abstract
Hair cells play key roles in hearing and balance, and hair cell loss would result in hearing loss or vestibular dysfunction. Cellular and molecular research in hair cell biology provides us a better understanding of hearing and deafness. Zebrafish, owing to their hair cell-enriched organs, have been widely applied in hair cell-related research worldwide. Similar to mammals, zebrafish have inner ear hair cells. In addition, they also have lateral line neuromast hair cells. These different types of hair cells vary in morphology and function. However, systematic analysis of their molecular characteristics remains lacking. In this study, we analyzed the GFP+ cells isolated from Tg(Brn3c:mGFP) larvae with GFP expression in all hair cells using single-cell RNA-sequencing (scRNA-seq). Three subtypes of hair cells, namely macula hair cell (MHC), crista hair cell (CHC), and neuromast hair cell (NHC), were characterized and validated by whole-mount in situ hybridization analysis of marker genes. The hair cell scRNA-seq data revealed hair cell-specific genes, including hearing loss genes that have been identified in humans and novel genes potentially involved in hair cell formation and function. Two novel genes were discovered to specifically function in NHCs and MHCs, corresponding to their specific expression in NHCs and MHCs. This study allows us to understand the specific genes in hair cell subpopulations of zebrafish, which will shed light on the genetics of both human vestibular and cochlear hair cell function.
Collapse
Affiliation(s)
- Fuping Qian
- School of Life Sciences, Nantong Laboratory of Development and Diseases, Nantong University, Nantong, 226019, China
| | - Guanyun Wei
- School of Life Sciences, Nantong Laboratory of Development and Diseases, Nantong University, Nantong, 226019, China
| | - Yajing Gao
- Co-Innovation Center of Neuroregeneration, School of Life SciencesKey Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong, 226019, China
| | - Xin Wang
- Co-Innovation Center of Neuroregeneration, School of Life SciencesKey Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong, 226019, China
| | - Jie Gong
- School of Life Sciences, Nantong Laboratory of Development and Diseases, Nantong University, Nantong, 226019, China
| | - Chao Guo
- School of Life Sciences, Nantong Laboratory of Development and Diseases, Nantong University, Nantong, 226019, China
| | - Xiaoning Wang
- Co-Innovation Center of Neuroregeneration, School of Life SciencesKey Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong, 226019, China
| | - Xu Zhang
- Co-Innovation Center of Neuroregeneration, School of Life SciencesKey Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong, 226019, China
| | - Jinxiang Zhao
- Co-Innovation Center of Neuroregeneration, School of Life SciencesKey Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong, 226019, China
| | - Cheng Wang
- School of Life Sciences, Nantong Laboratory of Development and Diseases, Nantong University, Nantong, 226019, China
| | - Mengting Xu
- Co-Innovation Center of Neuroregeneration, School of Life SciencesKey Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong, 226019, China
| | - Yuebo Hu
- Co-Innovation Center of Neuroregeneration, School of Life SciencesKey Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong, 226019, China
| | - Guoli Yin
- Co-Innovation Center of Neuroregeneration, School of Life SciencesKey Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong, 226019, China
| | - Jiahui Kang
- Institute of Reproductive Medicine, Medical School, Nantong University, Nantong, 226001, China
| | - Renjie Chai
- Co-Innovation Center of Neuroregeneration, School of Life SciencesKey Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong, 226019, China.
- State Key Laboratory of Bioelectronics, Co-Innovation Center of Neuroregeneration, Department of Otolaryngology Head and Neck Surgery, Zhongda Hospital, Jiangsu Province High-Tech Key Laboratory for Bio-Medical Research, School of Life Science and Technology, Southeast University, Nanjing, 210096, China.
- Institute for Stem Cell and Regeneration, Chinese Academy of Science, Beijing, 100864, China.
- Beijing Key Laboratory of Neural Regeneration and Repair, Capital Medical University, Beijing, 100069, China.
- Department of Otolaryngology Head and Neck Surgery, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China.
| | - Gangcai Xie
- Institute of Reproductive Medicine, Medical School, Nantong University, Nantong, 226001, China.
| | - Dong Liu
- School of Life Sciences, Nantong Laboratory of Development and Diseases, Nantong University, Nantong, 226019, China.
- Co-Innovation Center of Neuroregeneration, School of Life SciencesKey Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Nantong University, Nantong, 226019, China.
| |
Collapse
|
18
|
Neel BL, Nisler CR, Walujkar S, Araya-Secchi R, Sotomayor M. Collective mechanical responses of cadherin-based adhesive junctions as predicted by simulations. Biophys J 2022; 121:991-1012. [PMID: 35150618 PMCID: PMC8943820 DOI: 10.1016/j.bpj.2022.02.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 01/02/2022] [Accepted: 02/07/2022] [Indexed: 12/13/2022] Open
Abstract
Cadherin-based adherens junctions and desmosomes help stabilize cell-cell contacts with additional function in mechano-signaling, while clustered protocadherin junctions are responsible for directing neuronal circuits assembly. Structural models for adherens junctions formed by epithelial cadherin (CDH1) proteins indicate that their long, curved ectodomains arrange to form a periodic, two-dimensional lattice stabilized by tip-to-tip trans interactions (across junction) and lateral cis contacts. Less is known about the exact architecture of desmosomes, but desmoglein (DSG) and desmocollin (DSC) cadherin proteins are also thought to form ordered junctions. In contrast, clustered protocadherin (PCDH)-based cell-cell contacts in neuronal tissues are thought to be responsible for self-recognition and avoidance, and structural models for clustered PCDH junctions show a linear arrangement in which their long and straight ectodomains form antiparallel overlapped trans complexes. Here, we report all-atom molecular dynamics simulations testing the mechanics of minimalistic adhesive junctions formed by CDH1, DSG2 coupled to DSC1, and PCDHγB4, with systems encompassing up to 3.7 million atoms. Simulations generally predict a favored shearing pathway for the adherens junction model and a two-phased elastic response to tensile forces for the adhesive adherens junction and the desmosome models. Complexes within these junctions first unbend at low tensile force and then become stiff to unbind without unfolding. However, cis interactions in both the CDH1 and DSG2-DSC1 systems dictate varied mechanical responses of individual dimers within the junctions. Conversely, the clustered protocadherin PCDHγB4 junction lacks a distinct two-phased elastic response. Instead, applied tensile force strains trans interactions directly, as there is little unbending of monomers within the junction. Transient intermediates, influenced by new cis interactions, are observed after the main rupture event. We suggest that these collective, complex mechanical responses mediated by cis contacts facilitate distinct functions in robust cell-cell adhesion for classical cadherins and in self-avoidance signaling for clustered PCDHs.
Collapse
Affiliation(s)
- Brandon L Neel
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; The Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio
| | - Collin R Nisler
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; Biophysics Graduate Program, The Ohio State University, Columbus, Ohio
| | - Sanket Walujkar
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; Chemical Physics Graduate Program, The Ohio State University, Columbus, Ohio
| | - Raul Araya-Secchi
- Facultad de Ingenieria y Tecnologia, Universidad San Sebastian, Santiago, Chile
| | - Marcos Sotomayor
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio; The Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio; Biophysics Graduate Program, The Ohio State University, Columbus, Ohio; Chemical Physics Graduate Program, The Ohio State University, Columbus, Ohio.
| |
Collapse
|
19
|
Gupta C, Sarkar D, Tieleman DP, Singharoy A. The ugly, bad, and good stories of large-scale biomolecular simulations. Curr Opin Struct Biol 2022; 73:102338. [PMID: 35245737 DOI: 10.1016/j.sbi.2022.102338] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 11/29/2021] [Accepted: 01/24/2022] [Indexed: 12/20/2022]
Abstract
Molecular modeling of large biomolecular assemblies exemplifies a disruptive area holding both promises and contentions. Propelled by peta and exascale computing, several simulation methodologies have now matured into user-friendly tools that are successfully employed for modeling viruses, membranous nano-constructs, and key pieces of the genetic machinery. We present three unifying biophysical themes that emanate from some of the most recent multi-million atom simulation endeavors. Despite connecting molecular changes with phenotypic outcomes, the quality measures of these simulations remain questionable. We discuss the existing and upcoming strategies for constructing representative ensembles of large systems, how new computing technologies will boost this area, and make a point that integrative modeling guided by experimental data is the future of biomolecular computations.
Collapse
Affiliation(s)
- Chitrak Gupta
- School of Molecular Sciences, Center for Applied Structural Discovery, Arizona State University at Tempe, Tempe, AZ, 85282, USA; Biodesign Institute, Tempe, AZ, 85281, USA. https://twitter.com/ChitrakGupta2
| | - Daipayan Sarkar
- School of Molecular Sciences, Center for Applied Structural Discovery, Arizona State University at Tempe, Tempe, AZ, 85282, USA; MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824-1319, USA. https://twitter.com/17Dsarkar
| | - D Peter Tieleman
- Centre for Molecular Simulation and Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada.
| | - Abhishek Singharoy
- School of Molecular Sciences, Center for Applied Structural Discovery, Arizona State University at Tempe, Tempe, AZ, 85282, USA; Biodesign Institute, Tempe, AZ, 85281, USA.
| |
Collapse
|
20
|
Mechanotransduction in mammalian sensory hair cells. Mol Cell Neurosci 2022; 120:103706. [PMID: 35218890 PMCID: PMC9177625 DOI: 10.1016/j.mcn.2022.103706] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 02/14/2022] [Accepted: 02/18/2022] [Indexed: 11/23/2022] Open
Abstract
In the inner ear, the auditory and vestibular systems detect and translate sensory information regarding sound and balance. The sensory cells that transform mechanical input into an electrical signal in these systems are called hair cells. A specialized organelle on the apical surface of the hair cells called the hair bundle detects the mechanical signals. Displacement of the hair bundle causes mechanotransduction channels to open. The morphology and organization of the hair bundle, as well as the properties and characteristics of the mechanotransduction process, differ between the different hair cell types in the auditory and vestibular systems. These differences likely contribute to maximizing the transduction of specific signals in each system. This review will discuss the molecules essential for mechanotransduction and the properties of the mechanotransduction process, focusing our attention on recent data and differences between the auditory and vestibular systems.
Collapse
|
21
|
Al-Choboq J, Ferlazzo ML, Sonzogni L, Granzotto A, El-Nachef L, Maalouf M, Berthel E, Foray N. Usher Syndrome Belongs to the Genetic Diseases Associated with Radiosensitivity: Influence of the ATM Protein Kinase. Int J Mol Sci 2022; 23:ijms23031570. [PMID: 35163494 PMCID: PMC8836140 DOI: 10.3390/ijms23031570] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 01/23/2022] [Accepted: 01/27/2022] [Indexed: 12/23/2022] Open
Abstract
Usher syndrome (USH) is a rare autosomal recessive disease characterized by the combination of hearing loss, visual impairment due to retinitis pigmentosa, and in some cases vestibular dysfunctions. Studies published in the 1980s reported that USH is associated with cellular radiosensitivity. However, the molecular basis of this particular phenotype has not yet been documented. The aim of this study was therefore to document the radiosensitivity of USH1—a subset of USH—by examining the radiation-induced nucleo-shuttling of ATM (RIANS), as well as the functionality of the repair and signaling pathways of the DNA double-strand breaks (DSBs) in three skin fibroblasts derived from USH1 patients. The clonogenic cell survival, the micronuclei, the nuclear foci formed by the phosphorylated forms of the X variant of the H2A histone (ɣH2AX), the phosphorylated forms of the ATM protein (pATM), and the meiotic recombination 11 nuclease (MRE11) were used as cellular and molecular endpoints. The interaction between the ATM and USH1 proteins was also examined by proximity ligation assay. The results showed that USH1 fibroblasts were associated with moderate but significant radiosensitivity, high yield of micronuclei, and impaired DSB recognition but normal DSB repair, likely caused by a delayed RIANS, suggesting a possible sequestration of ATM by some USH1 proteins overexpressed in the cytoplasm. To our knowledge, this report is the first radiobiological characterization of cells from USH1 patients at both molecular and cellular scales.
Collapse
Affiliation(s)
- Joëlle Al-Choboq
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28 rue Laennec, 69008 Lyon, France; (J.A.-C.); (M.L.F.); (L.S.); (A.G.); (L.E.-N.); (E.B.)
| | - Mélanie L. Ferlazzo
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28 rue Laennec, 69008 Lyon, France; (J.A.-C.); (M.L.F.); (L.S.); (A.G.); (L.E.-N.); (E.B.)
| | - Laurène Sonzogni
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28 rue Laennec, 69008 Lyon, France; (J.A.-C.); (M.L.F.); (L.S.); (A.G.); (L.E.-N.); (E.B.)
| | - Adeline Granzotto
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28 rue Laennec, 69008 Lyon, France; (J.A.-C.); (M.L.F.); (L.S.); (A.G.); (L.E.-N.); (E.B.)
| | - Laura El-Nachef
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28 rue Laennec, 69008 Lyon, France; (J.A.-C.); (M.L.F.); (L.S.); (A.G.); (L.E.-N.); (E.B.)
| | - Mira Maalouf
- Department of Chemistry and Biochemistry, Faculty of Sciences II, Lebanese University, Fanar 1202, Lebanon;
| | - Elise Berthel
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28 rue Laennec, 69008 Lyon, France; (J.A.-C.); (M.L.F.); (L.S.); (A.G.); (L.E.-N.); (E.B.)
| | - Nicolas Foray
- Inserm, U1296 Unit, Radiation: Defense, Health and Environment, Centre Léon-Bérard, 28 rue Laennec, 69008 Lyon, France; (J.A.-C.); (M.L.F.); (L.S.); (A.G.); (L.E.-N.); (E.B.)
- Correspondence: ; Tel.: +33-4-78-78-28-28
| |
Collapse
|
22
|
Elferich J, Clark S, Ge J, Goehring A, Matsui A, Gouaux E. Molecular structures and conformations of protocadherin-15 and its complexes on stereocilia elucidated by cryo-electron tomography. eLife 2021; 10:74512. [PMID: 34964715 PMCID: PMC8776254 DOI: 10.7554/elife.74512] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 12/27/2021] [Indexed: 11/23/2022] Open
Abstract
Mechanosensory transduction (MT), the conversion of mechanical stimuli into electrical signals, underpins hearing and balance and is carried out within hair cells in the inner ear. Hair cells harbor actin-filled stereocilia, arranged in rows of descending heights, where the tips of stereocilia are connected to their taller neighbors by a filament composed of protocadherin 15 (PCDH15) and cadherin 23 (CDH23), deemed the ‘tip link.’ Tension exerted on the tip link opens an ion channel at the tip of the shorter stereocilia, thus converting mechanical force into an electrical signal. While biochemical and structural studies have provided insights into the molecular composition and structure of isolated portions of the tip link, the architecture, location, and conformational states of intact tip links, on stereocilia, remains unknown. Here, we report in situ cryo-electron microscopy imaging of the tip link in mouse stereocilia. We observe individual PCDH15 molecules at the tip and shaft of stereocilia and determine their stoichiometry, conformational heterogeneity, and their complexes with other filamentous proteins, perhaps including CDH23. The PCDH15 complexes occur in clusters, frequently with more than one copy of PCDH15 at the tip of stereocilia, suggesting that tip links might consist of more than one copy of PCDH15 complexes and, by extension, might include multiple MT complexes.
Collapse
Affiliation(s)
- Johannes Elferich
- Vollum Institute, Oregon Health and Science University, Portland, United States
| | - Sarah Clark
- Vollum Institute, Oregon Health and Science University, Portland, United States
| | - Jingpeng Ge
- Vollum Institute, Oregon Health and Science University, Portland, United States
| | - April Goehring
- Vollum Institute, Oregon Health and Science University, Portland, United States
| | - Aya Matsui
- Vollum Institute, Oregon Health and Science University, Portland, United States
| | - Eric Gouaux
- Vollum Institute, Oregon Health and Science University, Portland, United States
| |
Collapse
|
23
|
Gray ME, Johnson ZR, Modak D, Tamilselvan E, Tyska MJ, Sotomayor M. Heterophilic and homophilic cadherin interactions in intestinal intermicrovillar links are species dependent. PLoS Biol 2021; 19:e3001463. [PMID: 34871294 PMCID: PMC8691648 DOI: 10.1371/journal.pbio.3001463] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/21/2021] [Accepted: 10/30/2021] [Indexed: 11/19/2022] Open
Abstract
Enterocytes are specialized epithelial cells lining the luminal surface of the small intestine that build densely packed arrays of microvilli known as brush borders. These microvilli drive nutrient absorption and are arranged in a hexagonal pattern maintained by intermicrovillar links formed by 2 nonclassical members of the cadherin superfamily of calcium-dependent cell adhesion proteins: protocadherin-24 (PCDH24, also known as CDHR2) and the mucin-like protocadherin (CDHR5). The extracellular domains of these proteins are involved in heterophilic and homophilic interactions important for intermicrovillar function, yet the structural determinants of these interactions remain unresolved. Here, we present X-ray crystal structures of the PCDH24 and CDHR5 extracellular tips and analyze their species-specific features relevant for adhesive interactions. In parallel, we use binding assays to identify the PCDH24 and CDHR5 domains involved in both heterophilic and homophilic adhesion for human and mouse proteins. Our results suggest that homophilic and heterophilic interactions involving PCDH24 and CDHR5 are species dependent with unique and distinct minimal adhesive units.
Collapse
Affiliation(s)
- Michelle E. Gray
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio, United States of America
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
| | - Zachary R. Johnson
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
| | - Debadrita Modak
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
| | - Elakkiya Tamilselvan
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
- Biophysics Program, The Ohio State University, Columbus, Ohio, United States of America
| | - Matthew J. Tyska
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, United States of America
| | - Marcos Sotomayor
- Ohio State Biochemistry Program, The Ohio State University, Columbus, Ohio, United States of America
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, Ohio, United States of America
- Biophysics Program, The Ohio State University, Columbus, Ohio, United States of America
- * E-mail:
| |
Collapse
|
24
|
Holt JR, Tobin M, Elferich J, Gouaux E, Ballesteros A, Yan Z, Ahmed ZM, Nicolson T. Putting the Pieces Together: the Hair Cell Transduction Complex. J Assoc Res Otolaryngol 2021; 22:601-608. [PMID: 34617206 PMCID: PMC8599550 DOI: 10.1007/s10162-021-00808-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/16/2021] [Indexed: 11/30/2022] Open
Abstract
Identification of the components of the mechanosensory transduction complex in hair cells has been a major research interest for many auditory and vestibular scientists and has attracted attention from outside the field. The past two decades have witnessed a number of significant advances with emergence of compelling evidence implicating at least a dozen distinct molecular components of the transduction machinery. Yet, how the pieces of this ensemble fit together and function in harmony to enable the senses of hearing and balance has not been clarified. The goal of this review is to summarize a 2021 symposium presented at the annual mid-winter meeting of the Association for Research in Otolaryngology. The symposium brought together the latest insights from within and beyond the field to examine individual components of the transduction complex and how these elements interact at molecular, structural, and biophysical levels to gate mechanosensitive channels and initiate sensory transduction in the inner ear. The review includes a brief historical background to set the stage for topics to follow that focus on structure, properties, and interactions of proteins such as CDH23, PCDH15, LHFPL5, TMIE, TMC1/2, and CIB2/3. We aim to present the diversity of ideas in this field and highlight emerging theories and concepts. This review will not only provide readers with a deeper appreciation of the components of the transduction apparatus and how they function together, but also bring to light areas of broad agreement, areas of scientific controversy, and opportunities for future scientific discovery.
Collapse
Affiliation(s)
- Jeffrey R Holt
- Departments of Otolaryngology & Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, 02115, USA.
| | - Mélanie Tobin
- Laboratoire Physico-Chimie Curie, Institut Curie, Université PSL, Sorbonne Université, CNRS UMR168, Paris, 75005, France
- Departments of Otorhinolaryngology, Neuroscience and Neurology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Johannes Elferich
- Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Eric Gouaux
- Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
- Howard Hughes Medical Institute, Vollum Institute, Oregon Health & Science University, 3181 SW Sam Jackson Park Road, Portland, OR, 97239, USA
| | - Angela Ballesteros
- Molecular Physiology and Biophysics Section, Disorders and Stroke, National Institute of Neurological, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Zhiqiang Yan
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, 518132, China
| | - Zubair M Ahmed
- Department of Otolaryngology Head & Neck Surgery, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Teresa Nicolson
- Department of Otolaryngology-Head & Neck Surgery, Stanford University, Stanford, CA, USA
| |
Collapse
|
25
|
Mulhall EM, Ward A, Yang D, Koussa MA, Corey DP, Wong WP. Single-molecule force spectroscopy reveals the dynamic strength of the hair-cell tip-link connection. Nat Commun 2021; 12:849. [PMID: 33558532 PMCID: PMC7870652 DOI: 10.1038/s41467-021-21033-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Accepted: 01/08/2021] [Indexed: 01/11/2023] Open
Abstract
The conversion of auditory and vestibular stimuli into electrical signals is initiated by force transmitted to a mechanotransduction channel through the tip link, a double stranded protein filament held together by two adhesion bonds in the middle. Although thought to form a relatively static structure, the dynamics of the tip-link connection has not been measured. Here, we biophysically characterize the strength of the tip-link connection at single-molecule resolution. We show that a single tip-link bond is more mechanically stable relative to classic cadherins, and our data indicate that the double stranded tip-link connection is stabilized by single strand rebinding facilitated by strong cis-dimerization domains. The measured lifetime of seconds suggests the tip-link is far more dynamic than previously thought. We also show how Ca2+ alters tip-link lifetime through elastic modulation and reveal the mechanical phenotype of a hereditary deafness mutation. Together, these data show how the tip link is likely to function during mechanical stimuli.
Collapse
Affiliation(s)
- Eric M Mulhall
- Department of Neurobiology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Program in Neuroscience, Harvard University, Cambridge, MA, USA
| | - Andrew Ward
- Department of Neurobiology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Darren Yang
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Mounir A Koussa
- Department of Neurobiology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA
- Program in Neuroscience, Harvard University, Cambridge, MA, USA
| | - David P Corey
- Department of Neurobiology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
| | - Wesley P Wong
- Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA, USA.
- Department of Biological Chemistry and Molecular Pharmacology, Blavatnik Institute, Harvard Medical School, Boston, MA, USA.
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, MA, USA.
| |
Collapse
|
26
|
Garg S, Sagar A, Singaraju GS, Dani R, Bari NK, Naganathan AN, Rakshit S. Weakening of interaction networks with aging in tip-link protein induces hearing loss. Biochem J 2021; 478:121-134. [PMID: 33270084 PMCID: PMC7813477 DOI: 10.1042/bcj20200799] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 12/02/2020] [Accepted: 12/03/2020] [Indexed: 02/08/2023]
Abstract
Age-related hearing loss (ARHL) is a common condition in humans marking the gradual decrease in hearing with age. Perturbations in the tip-link protein cadherin-23 that absorbs the mechanical tension from sound and maintains the integrity of hearing is associated with ARHL. Here, in search of molecular origins for ARHL, we dissect the conformational behavior of cadherin-23 along with the mutant S47P that progresses the hearing loss drastically. Using an array of experimental and computational approaches, we highlight a lower thermodynamic stability, significant weakening in the hydrogen-bond network and inter-residue correlations among β-strands, due to the S47P mutation. The loss in correlated motions translates to not only a remarkable two orders of magnitude slower folding in the mutant but also to a proportionately complex unfolding mechanism. We thus propose that loss in correlated motions within cadherin-23 with aging may trigger ARHL, a molecular feature that likely holds true for other disease-mutations in β-strand-rich proteins.
Collapse
Affiliation(s)
- Surbhi Garg
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Amin Sagar
- Centre de Biochimie Structurale INSERM, CNRS, Université de Montpellier, Montpellier, France
| | - Gayathri S. Singaraju
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
| | - Rahul Dani
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - Naimat K. Bari
- Institute of Nano Science and Technology (INST), Phase-10, Sector-64, Mohali, Punjab 160062, India
| | - Athi N. Naganathan
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - Sabyasachi Rakshit
- Department of Chemical Sciences, Indian Institute of Science Education and Research Mohali, Punjab, India
- Centre for Protein Science Design and Engineering, Indian Institute of Science Education and Research Mohali, Punjab, India
| |
Collapse
|
27
|
Fast recovery of disrupted tip links induced by mechanical displacement of hair bundles. Proc Natl Acad Sci U S A 2020; 117:30722-30727. [PMID: 33199645 PMCID: PMC7720144 DOI: 10.1073/pnas.2016858117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Each of the sensory receptors responsible for hearing or balance—a hair cell—has a mechanosensitive hair bundle. Mechanical stimuli pull upon molecular filaments—the tip links—that open ionic channels in the hair bundle. Loud sounds can damage hearing by breaking the tip links; recovery by replacement of the constituent proteins then requires several hours. We disrupted the tip links in vitro by removing the calcium ions that stabilize them, and then monitored the electrical response or stiffness of hair bundles to determine whether the links could recover. We found that tip links recovered within seconds if their ends were brought back into contact. This form of repair might occur in normal ears to restore sensitivity after damage. Hearing and balance rely on the capacity of mechanically sensitive hair bundles to transduce vibrations into electrical signals that are forwarded to the brain. Hair bundles possess tip links that interconnect the mechanosensitive stereocilia and convey force to the transduction channels. A dimer of dimers, each of these links comprises two molecules of protocadherin 15 (PCDH15) joined to two of cadherin 23 (CDH23). The “handshake” that conjoins the four molecules can be disrupted in vivo by intense stimulation and in vitro by exposure to Ca2+ chelators. Using hair bundles from the rat’s cochlea and the bullfrog’s sacculus, we observed that extensive recovery of mechanoelectrical transduction, hair bundle stiffness, and spontaneous bundle oscillation can occur within seconds after Ca2+ chelation, especially if hair bundles are deflected toward their short edges. Investigating the phenomenon in a two-compartment ionic environment that mimics natural conditions, we combined iontophoretic application of a Ca2+ chelator to selectively disrupt the tip links of individual frog hair bundles with displacement clamping to control hair bundle motion and measure forces. Our observations suggest that, after the normal Ca2+ concentration has been restored, mechanical stimulation facilitates the reconstitution of functional tip links.
Collapse
|