A Mutation in Synaptojanin 2 Causes Progressive Hearing Loss in the ENU-Mutagenised Mouse Strain Mozart
Publication Year 2011-03-15, Volume 6, Issue #3, Page e17607
- Journal Title
- PLOS ONE
- Publication Type
- Journal Article
- Background: Hearing impairment is the most common sensory impairment in humans, affecting 1:1,000 births. We have identified an ENU generated mouse mutant, Mozart, with recessively inherited, non-syndromic progressive hearing loss caused by a mutation in the synaptojanin 2 (Synj2), a central regulatory enzyme in the phosphoinositide-signaling cascade. Methodology/Principal Findings: The hearing loss in Mozart is caused by a p.Asn538Lys mutation in the catalytic domain of the inositol polyphosphate 5-phosphatase synaptojanin 2. Within the cochlea, Synj2 mRNA expression was detected in the inner and outer hair cells but not in the spiral ganglion. Synj2(N538K) mutant protein showed loss of lipid phosphatase activity, and was unable to degrade phosphoinositide signaling molecules. Mutant Mozart mice (Synj2(N538K/N538K)) exhibited progressive hearing loss and showed signs of hair cell degeneration as early as two weeks of age, with fusion of stereocilia followed by complete loss of hair bundles and ultimately loss of hair cells. No changes in vestibular or neurological function, or other clinical or behavioral manifestations were apparent. Conclusions/Significance: Phosphoinositides are membrane associated signaling molecules that regulate many cellular processes including cell death, proliferation, actin polymerization and ion channel activity. These results reveal Synj2 as a critical regulator of hair cell survival that is essential for hair cell maintenance and hearing function.
- PUBLIC LIBRARY SCIENCE
- INOSITOL POLYPHOSPHATE 5-PHOSPHATASES; ZEBRAFISH NRC MUTANT; HAIR-CELLS; HEREDITARY DEAFNESS; TARGETED DISRUPTION; SUPPORTING CELLS; INNER-EAR; IN-VIVO; PHOSPHATASE; PHOSPHOINOSITIDES
- WEHI Research Division(s)
- Publisher's Version
- Open Access at Publisher's Site
- Rights Notice
- Copyright Manji et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Creation Date: 2011-03-15 12:00:00Last Modified: 0001-01-01 12:00:00