The LINC complex is essential for hearing

• Published in: The Journal of clinical investigation 2013-02, Vol.123 (2), p.740-750
• Main Authors: Horn, Henning F, Brownstein, Zippora, Lenz, Danielle R, Shivatzki, Shaked, Dror, Amiel A, Dagan-Rosenfeld, Orit, Friedman, Lilach M, Roux, Kyle J, Kozlov, Serguei, Jeang, Kuan-Teh, Frydman, Moshe, Burke, Brian, Stewart, Colin L, Avraham, Karen B
• Format: Article
• Language: English
• Subjects: Animals; Biomedical research; Cellular proteins; Chromosomes; DNA Mutational Analysis; Female; Ferrous Compounds; Gene mutations; Genes; Genetic aspects; Hair Cells, Auditory, Outer - pathology; Hair Cells, Auditory, Outer - physiology; Health aspects; Hearing - genetics; Hearing - physiology; Hearing loss; Hearing Loss, High-Frequency - etiology; Hearing Loss, High-Frequency - genetics; Hearing Loss, High-Frequency - physiopathology; Hearing protection; Humans; Iraq - ethnology; Israel; Jews - genetics; Localization; Male; Membrane Proteins - deficiency; Membrane Proteins - genetics; Membrane Proteins - physiology; Membranes; Mice; Mice, Inbred C57BL; Mice, Knockout; Motility; Multiprotein Complexes - deficiency; Multiprotein Complexes - genetics; Multiprotein Complexes - physiology; Mutation; Nuclear Envelope - metabolism; Nuclear Proteins - deficiency; Nuclear Proteins - genetics; Nuclear Proteins - physiology; Pedigree; Physiological aspects; Proteins; Risk factors; Sound waves
• ISSN: 0021-9738; 1558-8238
• DOI: 10.1172/JCI66911

Hereditary hearing loss is the most common sensory deficit. We determined that progressive high-frequency hearing loss in 2 families of Iraqi Jewish ancestry was due to homozygosity for the protein truncating mutation SYNE4 c.228delAT. SYNE4, a gene not previously associated with hearing loss, encodes nesprin-4 (NESP4), an outer nuclear membrane (ONM) protein expressed in the hair cells of the inner ear. The truncated NESP4 encoded by the families' mutation did not localize to the ONM. NESP4 and SUN domain-containing protein 1 (SUN1), which localizes to the inner nuclear membrane (INM), are part of the linker of nucleoskeleton and cytoskeleton (LINC) complex in the nuclear envelope. Mice lacking either Nesp4 or Sun1 were evaluated for hair cell defects and hearing loss. In both Nesp4-/- and Sun1-/- mice, OHCs formed normally, but degenerated as hearing matured, leading to progressive hearing loss. The nuclei of OHCs from mutant mice failed to maintain their basal localization, potentially affecting cell motility and hence the response to sound. These results demonstrate that the LINC complex is essential for viability and normal morphology of OHCs and suggest that the position of the nucleus in sensory epithelial cells is critical for maintenance of normal hearing.