Mutation-induced reinforcement of prestin-expressing cells.
The motor protein prestin in cochlear outer hair cells is a member of the solute carrier 26 family, but among the proteins of that family, only prestin can confer the cells with nonlinear capacitance (NLC) and motility. In the present study, to clarify contributions of unique amino acids of prestin, namely, Met-122, Met-225 and Thr-428, to the characteristics of prestin, mutations were introduced into those amino acids. As a result, NLC remained unchanged by both replacement of Met-122 by isoleucine and that of Thr-428 by leucine, suggesting that those amino acids were not important for the generation of NLC. Surprisingly, the replacement of Met-225 by glutamine statistically increased NLC as well as the motility of prestin-expressing cells without an increase in the amount of prestin expression in the plasma membrane. This indicates that Met-225 in prestin somehow adjusts NLC and the motility of prestin-expressing cells.
Kumano
Shun
S
Department of Bioengineering and Robotics, Tohoku University, Sendai, Japan. kumano@wadalab.mech.tohoku.ac.jp
Tan
Xiaodong
X
He
David Z Z
DZ
Iida
Koji
K
Murakoshi
Michio
M
Wada
Hiroshi
H
D000595:Amino Acid Sequence / Q000235:genetics; D027321:Anion Transport Proteins / Q000235:genetics / Q000502:physiology*; D002460:Cell Line; D002465:Cell Movement; D025802:Electric Capacitance; D006801:Humans; D008715:Methionine / Q000235:genetics; D017354:Point Mutation; D000076988:Sulfate Transporters; D013912:Threonine / Q000235:genetics
D027321:Anion Transport Proteins; C498719:SLC26A5 protein, human; D000076988:Sulfate Transporters; D013912:Threonine; D008715:Methionine