Structural highlights
Disease
CAD23_MOUSE Defects in Cdh23 are the cause of waltzer (v) phenotype. Waltzer mice are characterized by deafness and vestibular dysfunction due to degeneration of the neuroepithelium within the inner ear.
Function
CAD23_MOUSE Cadherins are calcium-dependent cell adhesion proteins. They preferentially interact with themselves in a homophilic manner in connecting cells. CDH23 is required for establishing and/or maintaining the proper organization of the stereocilia bundle of hair cells in the cochlea and the vestibule during late embryonic/early postnatal development. It is part of the functional network formed by USH1C, USH1G, CDH23 and MYO7A that mediates mechanotransduction in cochlear hair cells. Required for normal hearing.[1]
Publication Abstract from PubMed
Cadherin-23 (CDH23) is an essential component of hair-cell tip links, fine filaments that mediate inner-ear mechanotransduction. The extracellular domain of CDH23 forms about three-fourths of the tip link with 27 extracellular cadherin (EC) repeats that are structurally similar but not identical to each other. Calcium (Ca(2+)) coordination at the EC linker regions is key for tip-link elasticity and function. There are approximately 116 sites in CDH23 affected by deafness-causing mutations, many of which alter conserved Ca(2+)-binding residues. Here we present crystal structures showing 18 CDH23 EC repeats, including the most and least conserved, a fragment carrying disease mutations, and EC repeats with non-canonical Ca(2+)-binding motif sequences and unusual secondary structure. Complementary experiments show deafness mutations' effects on stability and affinity for Ca(2+). Additionally, a model of nine contiguous CDH23 EC repeats reveals helicity and potential parallel dimerization faces. Overall, our studies provide detailed structural insight into CDH23 function in mechanotransduction.
Zooming in on Cadherin-23: Structural Diversity and Potential Mechanisms of Inherited Deafness.,Jaiganesh A, De-la-Torre P, Patel AA, Termine DJ, Velez-Cortes F, Chen C, Sotomayor M Structure. 2018 Jun 27. pii: S0969-2126(18)30209-0. doi:, 10.1016/j.str.2018.06.003. PMID:30033219[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Di Palma F, Holme RH, Bryda EC, Belyantseva IA, Pellegrino R, Kachar B, Steel KP, Noben-Trauth K. Mutations in Cdh23, encoding a new type of cadherin, cause stereocilia disorganization in waltzer, the mouse model for Usher syndrome type 1D. Nat Genet. 2001 Jan;27(1):103-7. PMID:11138008 doi:http://dx.doi.org/10.1038/83660
- ↑ Jaiganesh A, De-la-Torre P, Patel AA, Termine DJ, Velez-Cortes F, Chen C, Sotomayor M. Zooming in on Cadherin-23: Structural Diversity and Potential Mechanisms of Inherited Deafness. Structure. 2018 Jun 27. pii: S0969-2126(18)30209-0. doi:, 10.1016/j.str.2018.06.003. PMID:30033219 doi:http://dx.doi.org/10.1016/j.str.2018.06.003
