Prestin forms oligomer with four mechanically independent subunits

Xiang Wang, Shiming Yang, Shuping Jia, David Z.Z. He

Research output: Contribution to journalArticle

31 Scopus citations

Abstract

Prestin is the motor protein of cochlear outer hair cells (OHCs) with the unique capability of performing direct, rapid, and reciprocal electromechanical conversion. Prestin consists of 744 amino acids with a molecular mass of ∼ 81.4 kDa. The predicted membrane topology and molecular mass of a single prestin molecule appear inadequate to account for the size of intramembrane particles (IMPs) expressed in the OHC membrane. Although recent biochemical evidence suggests that prestin forms homo-oligomers, most likely as a tetramer, the oligomeric structure of prestin in OHCs remains unclear. We obtained the charge density of prestin in the gerbil OHCs by measuring their nonlinear capacitance (NLC). The average charge density (22,608 μm-2) measured was four times the average IMP density (5686 μm-2) reported in the freeze-fracture study. This suggests that each IMP contains four prestin molecules, based on the general notion that each prestin transfers a single elementary charge. We subsequently compared the voltage dependency and the values of slope factor of NLC and somatic motility simultaneously measured from the same OHCs to determine whether NLC and motility are fully coupled and how prestin subunits function within the tetramer. We showed that the voltage dependency and slope factors of NLC and motility were not statistically different, suggesting that NLC and motility are fully coupled. The fact that the slope factor is the same between NLC and motility suggests that each prestin monomer in the tetramer is in parallel, each interacting independently with cytoplasmic or other partners to facilitate the mechanical response.

Original languageEnglish (US)
Pages (from-to)28-35
Number of pages8
JournalBrain Research
Volume1333
DOIs
StatePublished - May 28 2010

All Science Journal Classification (ASJC) codes

  • Neuroscience(all)
  • Molecular Biology
  • Clinical Neurology
  • Developmental Biology

Fingerprint Dive into the research topics of 'Prestin forms oligomer with four mechanically independent subunits'. Together they form a unique fingerprint.

  • Cite this