title: N-terminal-mediated homomultimerization of prestin, the outer hair cell motor protein.
abstract: The outer hair cell lateral membrane motor, prestin, drives the cell's mechanical response that underpins mammalian cochlear amplification. Little is known about the protein's structure-function relations. Here we provide evidence that prestin is a 10-transmembrane domain protein whose membrane topology differs from that of previous models. We also present evidence that both intracellular termini of prestin are required for normal voltage sensing, with short truncations of either terminal resulting in absent or modified activity despite quantitative findings of normal membrane targeting. Finally, we show with fluorescence resonance energy transfer that prestin-prestin interactions are dependent on an intact N-terminus, suggesting that this terminus is important for homo-oligomerization of prestin. These domains, which we have perturbed, likely contribute to allosteric modulation of prestin via interactions among prestin molecules or possibly between prestin and other proteins, as well.
authors.affiliation: Departments of Neurology and Neurobiology, and Otolaryngology and Neurobiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06510, USA.
authors.forename: Dhasakumar
authors.initials: D
authors.lastname: Navaratnam
authors.forename: Jun-Ping
authors.initials: JP
authors.lastname: Bai
authors.forename: Haresha
authors.initials: H
authors.lastname: Samaranayake
authors.forename: Joseph
authors.initials: J
authors.lastname: Santos-Sacchi
mesh_terms: D000495:Allosteric Site; D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D002462:Cell Membrane / Q000378:metabolism; D002469:Cell Separation; D006224:Cricetinae; D019281:Dimerization; D025802:Electric Capacitance; D004553:Electric Conductivity; D004594:Electrophysiology; D005434:Flow Cytometry; D031541:Fluorescence Resonance Energy Transfer; D005849:Gerbillinae; D049452:Green Fluorescent Proteins / Q000737:chemistry; D018072:Hair Cells, Auditory, Outer / Q000378:metabolism*; D040542:Mechanotransduction, Cellular; D008564:Membrane Potentials; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D020409:Molecular Motor Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D011485:Protein Binding; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry*; D014162:Transfection
chemical_list: C485182:Cyan Fluorescent Protein; D020409:Molecular Motor Proteins; C498720:Pres protein, mouse; D011506:Proteins; D049452:Green Fluorescent Proteins