Journal of Smooth Muscle Research
Online ISSN : 1884-8796
Print ISSN : 0916-8737
ISSN-L : 0916-8737
Inhibitory effects of rubratoxin A, a potent inhibitor of protein phosphatase 2, on the Ca2+-dependent contraction of skinned carotid artery from guinea pig
Yasuyuki NarakiMasaru WatanabeKosuke Takeya
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2019 Volume 55 Pages 14-22


Rubratoxin A, a potent inhibitor of PP2A, is known to suppress smooth muscle contraction. The inhibitory role of PP2A in smooth muscle contraction is still unclear. In order to clarify the regulatory mechanisms of PP2A on vascular smooth muscle contractility, we examined the effects of rubratoxin A on the Ca2+-induced contraction of β-escin skinned carotid artery preparations from guinea pigs. Rubratoxin A at 1 µM and 10 µM significantly inhibited skinned carotid artery contraction at any Ca2+ concentration. The data fitting to the Hill equation in [Ca2+]-contraction relationship indicated that rubratoxin A decreased Fmax-Ca2+ and increased [Ca2+]50, indices of Ca2+ sensitivity for the force and myosin-actin interaction, respectively. These results suggest that PP2A inhibition causes downregulation of the myosin light chain phosphorylation and direct interference with myosin-actin interaction.

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この記事はクリエイティブ・コモンズ [表示 - 非営利 4.0 国際]ライセンスの下に提供されています。
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