Calcium-dependent regulation of the motor activity of recombinant full-length Physarum myosin.
We successfully synthesized full-length and the mutant Physarum myosin and heavy meromyosin (HMM) constructs associated with Physarum regulatory light chain and essential light chain (PhELC) using Physarum myosin heavy chain in Sf-9 cells, and examined their Ca(2+)-mediated regulation. Ca(2+) inhibited the motility and ATPase activities of Physarum myosin and HMM. The Ca(2+) effect is also reversible at the in vitro motility of Physarum myosin. We demonstrated that full-length myosin increases the Ca(2+) inhibition more effectively than HMM. Furthermore, Ca(2+) did not affect the motility and ATPase activities of the mutant Physarum myosin with PhELC that lost Ca(2+)-binding ability. Therefore, we conclude that PhELC plays a critical role in Ca(2+)-dependent regulation of Physarum myosin.
Department of Molecular and Cellular Pharmacology, Gunma University Graduate School of Medicine, 3-39-22 Showa-Machi, Maebashi, Gunma, Japan.
Ying
Y
Zhang
Hozumi
H
Kawamichi
Hideyuki
H
Tanaka
Shinji
S
Yoshiyama
Kazuhiro
K
Kohama
Akio
A
Nakamura
D000818:Animals; D002118:Calcium / Q000378:metabolism* / Q000494:pharmacology; D002478:Cells, Cultured; D009154:Mutation; D018994:Myosin Light Chains / Q000235:genetics / Q000378:metabolism; D015879:Myosin Subfragments / Q000235:genetics / Q000378:metabolism; D009218:Myosins / Q000235:genetics / Q000378:metabolism*; D010804:Physarum / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism
D018994:Myosin Light Chains; D015879:Myosin Subfragments; D011994:Recombinant Proteins; D009218:Myosins; D002118:Calcium