Prestin-prestin and prestin-GLUT5 interactions in HEK293T cells.

The remarkable hearing sensitivity and frequency selectivity in mammals is attributed to cochlear amplifier in the outer hair cells (OHCs). Prestin, a membrane protein in the lateral wall of OHC plasma membrane, is required for OHC electromotility and cochlear amplifier. In addition, GLUT5, a fructose transporter, is reported to be abundant in the plasma membrane of the OHC lateral wall and has been originally proposed as the OHC motor protein. Here we provide evidence of interactions between prestin/prestin and prestin/GLUT5 in transiently transfected HEK293T cells. We used a combination of techniques: (1) membrane colocalization by confocal microscopy, (2) fluorescence resonance energy transfer (FRET) by fluorescence activated cell sorting (FACS), (3) FRET by acceptor photobleaching, (4) FRET by fluorescence lifetime imaging (FRET-FLIM), and (5) coimmunoprecipitation. Our results suggest that homomeric and heteromeric prestin interactions occur in native OHCs to facilitate its electromotile function and that GLUT5 interacts with prestin for its elusive function.