The LINC complex is essential for hearing.
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.
Institute of Medical Biology, A STAR, Singapore.
Henning F
HF
Horn
Zippora
Z
Brownstein
Danielle R
DR
Lenz
Shaked
S
Shivatzki
Amiel A
AA
Dror
Orit
O
Dagan-Rosenfeld
Lilach M
LM
Friedman
Kyle J
KJ
Roux
Serguei
S
Kozlov
Kuan-Teh
KT
Jeang
Moshe
M
Frydman
Brian
B
Burke
Colin L
CL
Stewart
Karen B
KB
Avraham
D000818:Animals; D004252:DNA Mutational Analysis; D005260:Female; D005296:Ferrous Compounds; D018072:Hair Cells, Auditory, Outer / Q000473:pathology / Q000502:physiology; D006309:Hearing / Q000235:genetics / Q000502:physiology*; D006316:Hearing Loss, High-Frequency / Q000209:etiology / Q000235:genetics / Q000503:physiopathology; D006801:Humans; D007493:Iraq / Q000208:ethnology; D007557:Israel; D007585:Jews / Q000235:genetics; D008297:Male; D008565:Membrane Proteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D046912:Multiprotein Complexes / Q000172:deficiency / Q000235:genetics / Q000502:physiology*; D009154:Mutation; D009685:Nuclear Envelope / Q000378:metabolism; D009687:Nuclear Proteins / Q000172:deficiency / Q000235:genetics / Q000502:physiology; D010375:Pedigree
C546614:BAE-2Fc; D005296:Ferrous Compounds; D008565:Membrane Proteins; D046912:Multiprotein Complexes; D009687:Nuclear Proteins; C539339:nesprin 4 protein, mouse