Open AccessDifferences in molecular mechanisms of K+ clearance in the auditory sensory epithelium of birds and mammals
Author(s) -
Viviane Wilms,
Chris Söffgen,
Hans Gerd Nothwang
Publication year - 2017
Publication title -
journal of experimental biology
Language(s) - English
Resource type - Journals
eISSN - 1477-9145
pISSN - 0022-0949
DOI - 10.1242/jeb.158030
Subject(s) - vertebrate , sensory system , biology , hair cell , microbiology and biotechnology , inner ear , efflux , basilar membrane , mechanism (biology) , epithelium , transduction (biophysics) , anatomy , cochlea , neuroscience , biophysics , gene , biochemistry , genetics , philosophy , epistemology
Mechanoelectrical transduction in the vertebrate inner ear is a highly conserved mechanism depending on K+ influx into hair cells. Here, we investigated the molecular underpinnings of subsequent K+ recycling in the chicken basilar papilla and compared it with those in the mammalian auditory sensory epithelium. Like mammals, the avian auditory hair cell uses KCNQ4, KCNMA1, and KCNMB1 as K+ efflux systems. Expression of KCNQ1 and KCNE1 suggests an additional efflux apparatus in avian hair cells. Marked differences were observed for K+ clearance. In mammals, KCC3, KCC4, Kir4.1, and CLC-K are present in supporting cells. Of these proteins, only CLC-K is expressed in avian supporting cells. Instead, they possess NKCC1 to move K+ across the membrane. This expression pattern suggests an avian clearance mechanism reminiscent of the well-established K+ uptake apparatus present in inner ear secretory cells. Altogether, tetrapod hair cells show similar mechanisms and supporting cells distinct molecular underpinnings of K+ recycling.