Absence of plastin 1 causes abnormal maintenance of hair cell stereocilia and a moderate form of hearing loss in mice.
Bottom Line: Several actin-associated proteins are essential for stereocilia formation and maintenance, and their absence leads to deafness.Auditory hair cells developed normally in Pls1 KO, but in young adult animals, the stereocilia of inner hair cells were reduced in width and length.These results show that in contrast to other actin-bundling proteins such as espin, harmonin or Eps8, plastin 1 is dispensable for the initial formation of stereocilia.
Affiliation: Centre for Auditory Research, UCL Ear Institute, University College London, London, UK.Show MeSH
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Mentions: We next asked whether mature (P24) IHCs from Pls1 KO mice had normal biophysical properties, such as a rapidly activating large conductance Ca2+-activated K+ current (IK,f) and a current carried by KCNQ4 channels (IK,n) with an unusually hyperpolarized activation range (25). Depolarizing and hyperpolarizing voltage steps from the holding potential of −64 mV elicited similar voltage-dependent outward K+ currents in all IHCs tested from het and Pls1 KO mice (Fig. 7A–C). IK,f and IK,n were expressed with a similar amplitude in IHCs from both genotypes (Table 2). Voltage responses as well as all other biophysical properties (Table 2) were also similar between het and Pls1 KO IHCs (Fig. 7D and E), indicating that the absence of plastin 1 has no impact on the overall acquisition of the biophysical characteristics of IHCs.Table 2.
Affiliation: Centre for Auditory Research, UCL Ear Institute, University College London, London, UK.