Smooth muscle myosin filament assembly under control of a kinase-related protein (KRP) and caldesmon

Kudryashov, D.S.; Vorotnikov, A.V.; Dudnakova, T.V.; Stepanova, O.V.; Lukas, T.J.; Sellers, J.R.; Martin, W.D.; Shirinsky, V.P.

Авторы: Kudryashov Dmitry S., Vorotnikov Alexander V., Dudnakova Tatyana V., Stepanova Olga V., Lukas Thomas J., Sellers James R., Martin Watterson D., Shirinsky Vladimir P.
Журнал: Journal of Muscle Research and Cell Motility
Том: 23
Номер: 4
Год издания: 2002
Издательство: Springer Nature
Местоположение издательства: Switzerland
Первая страница: 341
Последняя страница: 351
DOI: 10.1023/A:1022086228770
Аннотация: Kinase-related protein (KRP) and caldesmon are abundant myosin-binding proteins of smooth muscle. KRP induces the assembly of unphosphorylated smooth muscle myosin filaments in the presence of ATP by promoting the unfolded state of myosin. Based upon electron microscopy data, it was suggested that caldesmon also possessed a KRP-like activity (Katayama et al., 1995, J Biol Chem 270: 3919-3925). However, the nature of its activity remains obscure since caldesmon does not affect the equilibrium between the folded and unfolded state of myosin. Therefore, to gain some insight into this problem we compared the effects of KRP and caldesmon, separately, and together on myosin filaments using turbidity measurements, protein sedimentation and electron microscopy. Turbidity assays demonstrated that KRP reduced myosin filament aggregation, while caldesmon had no effect. Additionally, neither caldesmon nor its N-terminal myosin binding domain (N152) induced myosin polymerization at subthreshold Mg2+ concentrations in the presence of ATP, whereas the filament promoting action of KRP was enhanced by Mg2+. Moreover, the amino-terminal myosin binding fragment of caldesmon, like the whole protein, antagonizes Mg(2+)-induced myosin filament formation. In electron microscopy experiments, caldesmon shortened myosin filaments in the presence of Mg2+ and KRP, but N152 failed to change their appearance from control. Therefore, the primary distinction between caldesmon and KRP appears to be that caldesmon interacts with myosin to limit filament extension, while KRP induces filament propagation into defined polymers. Transfection of tagged-KRP into fibroblasts and overlay of fibroblast cytoskeletons with Cy3KRP demonstrated that KRP colocalizes with myosin structures in vivo. We propose a new model that through their independent binding to myosin and differential effects on myosin dynamics, caldesmon and KRP can, in concert, control the length and polymerization state of myosin filaments.
Добавил в систему: Воротников Александр Вячеславович

	ИСТИНА	Войти в систему Регистрация
	Интеллектуальная Система Тематического Исследования НАукометрических данных
	Главная Поиск Статистика О проекте Помощь

ИСТИНА

Интеллектуальная Система Тематического Исследования НАукометрических данных

Smooth muscle myosin filament assembly under control of a kinase-related protein (KRP) and caldesmonстатья

Прикрепленные файлы