Joseph Santos-Sacchi

Lei Song18
Dhasakumar Navaratnam9
Jun-Ping Bai7
Shumin Bian4
Alexei Surguchev3
18Lei Song
9Dhasakumar Navaratnam
7Jun-Ping Bai
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Mitochondrial dysfunction causes poorly understood tissue-specific pathology stemming from primary defects in respiration, coupled with altered reactive oxygen species (ROS), metabolic signaling, and apoptosis. The A1555G mtDNA mutation that causes maternally inherited deafness disrupts mitochondrial ribosome function, in part, via increased methylation of(More)
Chloride ions have been hypothesized to interact with the membrane outer hair cell (OHC) motor protein, prestin on its intracellular domain to confer voltage sensitivity (Oliver et al., 2001). Thus, we hypothesized previously that transmembrane chloride movements via the lateral membrane conductance of the cell, GmetL, could serve to underlie cochlear(More)
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(More)
Sensory hair cell ribbon synapses respond to graded stimulation in a linear, indefatigable manner, requiring that vesicle trafficking to synapses be rapid and nonrate-limiting. Real-time monitoring of vesicle fusion identified two release components. The first was saturable with both release rate and magnitude varying linearly with Ca(2+), however the(More)
The amplification of acoustic stimuli is a feature of hair cells that evolved early on in vertebrates. Though standard stereocilia mechanisms to promote such amplification may persist in the mammal, an additional mechanism evolved to enhance high frequency sensation. Only in mammals, a special cell type, the outer hair cell, arose that possesses a(More)
The development of motor protein activity in the lateral membrane of the mouse outer hair cell (OHC) from postnatal day 5 (P5) to P18 was investigated under whole-cell voltage clamp. Voltage-dependent, nonlinear capacitance (C (v)), which represents the conformational fluctuations of the motor molecule, progressively increased during development. At P12,(More)
The integral membrane protein prestin, a member of the SLC26 anion transporter family, is responsible for the voltage-driven electromotility of mammalian outer hair cells. It was argued that the evolution of prestin's motor function required a loss of the protein's transport capabilities. Instead, it was proposed that prestin manages only an abortive(More)
There are known differences in the properties of hair cells along the tonotopic axis of the avian auditory epithelium, the basilar papilla (BP). To determine the genetic basis of these differences, we compared gene expression between the high- (HF), middle-, and low-frequency (LF) thirds of 0-day-old chick auditory epithelia. RNA amplified from each sample(More)
Specialized sensory-transducing hair cells regenerate in response to injury in non-mammalian vertebrates such as birds and fish but not in mammals. Previous work has shown that overexpression of microRNA181a (miR181a) in cultured chicken basilar papillae, the avian counterpart of the cochlea, is sufficient to stimulate proliferation with production of new(More)
In the outer hair cell (OHC), membrane capacitance principally derives from two components - that associated with lateral membrane sensor/motor charge movement, and that proportional to the membrane surface area (C(sa)). We used measures of membrane capacitance to test a model hypothesis that OHC lateral membrane molecular motors, recently identified as the(More)