Calcium regulation of the ATPase activity of Physarum and scallop myosins using hybrid smooth muscle myosin: the role of the essential light chain.
To examine the role of two light chains (LCs) of the myosin II on Ca2+ regulation, we produced hybrid heavy meromyosin (HMM) having LCs from Physarum and/or scallop myosin using the smooth muscle myosin heavy chain. Ca2+ inhibited motility and ATPase activity of hybrid HMMs with LCs from Physarum myosin but activated those of hybrid HMM with LCs from scallop myosin, indicating an active role of LCs. ATPase activity of hybrid HMMs with LCs from different species showed the same effect by Ca2+ even though they did not support motility. Our results suggest that communication between the original combinations of LC is important for the motor function.
Zhang
Ying
Y
Department of Molecular and Cellular Pharmacology, Faculty of Medicine, Gunma University Graduate School of Medicine, 3-39-22 Showa-Machi, Maebashi, Gunma 371-8511, Japan.
Nakamura
Akio
A
Kawamichi
Hozumi
H
Yoshiyama
Shinji
S
Katayama
Takeshi
T
Kohama
Kazuhiro
K
D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D004789:Enzyme Activation / Q000187:drug effects; D018994:Myosin Light Chains / Q000378:metabolism*; D015879:Myosin Subfragments / Q000378:metabolism*; D049897:Pectinidae / Q000187:drug effects / Q000201:enzymology*; D010804:Physarum / Q000187:drug effects / Q000201:enzymology*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D024745:Smooth Muscle Myosins / Q000302:isolation & purification / Q000378:metabolism*
D018994:Myosin Light Chains; D015879:Myosin Subfragments; D011994:Recombinant Proteins; D024745:Smooth Muscle Myosins; D002118:Calcium