A chemical-genetic strategy implicates myosin-1c in adaptation by hair cells.
Myosin-1c (also known as myosin-Ibeta) has been proposed to mediate the slow component of adaptation by hair cells, the sensory cells of the inner ear. To test this hypothesis, we mutated tyrosine-61 of myosin-1c to glycine, conferring susceptibility to inhibition by N(6)-modified ADP analogs. We expressed the mutant myosin-1c in utricular hair cells of transgenic mice, delivered an ADP analog through a whole-cell recording pipette, and found that the analog rapidly blocked adaptation to positive and negative deflections in transgenic cells but not in wild-type cells. The speed and specificity of inhibition suggests that myosin-1c participates in adaptation in hair cells.
Holt
Jeffrey R
JR
Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
Gillespie
Susan K H
SK
Provance
D William
DW
Shah
Kavita
K
Shokat
Kevan M
KM
Corey
David P
DP
Mercer
John A
JA
Gillespie
Peter G
PG
D000244:Adenosine Diphosphate; D000818:Animals; D006198:Hair Cells, Auditory / Q000502:physiology*; D006309:Hearing / Q000235:genetics / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D020409:Molecular Motor Proteins / Q000737:chemistry* / Q000235:genetics; D009154:Mutation; D018995:Myosin Heavy Chains / Q000737:chemistry* / Q000235:genetics / Q000502:physiology
D020409:Molecular Motor Proteins; C491827:Myo1a protein, mouse; D000244:Adenosine Diphosphate; D018995:Myosin Heavy Chains