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A synthetic prestin reveals protein domains and molecular operation of outer hair cell piezoelectricity
Author(s) -
Schaechinger Thorsten J,
Gorbunov Dmitry,
Halaszovich Christian R,
Moser Tobias,
Kügler Sebastian,
Fakler Bernd,
Oliver Dominik
Publication year - 2011
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2011.202
Subject(s) - biology , prestin , hair cell , microbiology and biotechnology , computational biology , biophysics , cochlea , anatomy
Prestin, a transporter‐like protein of the SLC26A family, acts as a piezoelectric transducer that mediates the fast electromotility of outer hair cells required for cochlear amplification and auditory acuity in mammals. Non‐mammalian prestin orthologues are anion transporters without piezoelectric activity. Here, we generated synthetic prestin (SynPres), a chimera of mammalian and non‐mammalian prestin exhibiting both, piezoelectric properties and anion transport. SynPres delineates two distinct domains in the protein's transmembrane core that are necessary and sufficient for generating electromotility and associated non‐linear charge movement (NLC). Functional analysis of SynPres showed that the amplitude of NLC and hence electromotility are determined by the transport of monovalent anions. Thus, prestin‐mediated electromotility is a dual‐step process: transport of anions by an alternate access cycle, followed by an anion‐dependent transition generating electromotility. The findings define structural and functional determinants of prestin's piezoelectric activity and indicate that the electromechanical process evolved from the ancestral transport mechanism.