Inagaki M, Yokokura H, Itoh T, Kanmura Y, Kuriyama H, Hidaka H
Arch Biochem Biophys. 1987 Apr;254(1):136-41. doi: 10.1016/0003-9861(87)90089-0.
To clarify the role of protein kinase C in the mechanical response, the effects of exogenous protein kinase C and its cofactors were investigated on skinned smooth muscle preparations of the rabbit mesenteric artery. Addition of protein kinase C with 12-O-tetradecanoylphorbol-13-acetate (TPA) and phosphatidylserine (PS) caused slow inactivation of a maximal Ca2+ contraction of the muscle fiber and correspondingly increased protein kinase C phosphorylation of myosin light chain. Neither protein kinase C nor enzyme cofactors (PS and TPA) produced relaxation of this tissue and all three components caused significant relaxation. Furthermore, when the muscle fiber was activated by Ca2+-insensitive fragment of MLC-kinase, addition of protein kinase C with PS and TPA decreased the tension and increased protein kinase C phosphorylation of myosin light chain. This evidence suggests that protein kinase C phosphorylation of myosin light chain may play an inhibitory role in the contraction of vascular smooth muscle.
为阐明蛋白激酶C在机械反应中的作用，研究了外源性蛋白激酶C及其辅因子对兔肠系膜动脉去表皮平滑肌制剂的影响。添加蛋白激酶C与12 - O - 十四烷酰佛波醇 - 13 - 乙酸酯（TPA）和磷脂酰丝氨酸（PS）会导致肌纤维最大Ca2 +收缩的缓慢失活，并相应增加肌球蛋白轻链的蛋白激酶C磷酸化。蛋白激酶C及其酶辅因子（PS和TPA）均未使该组织松弛，且这三种成分均引起显著松弛。此外，当肌纤维由MLC - 激酶的Ca2 +不敏感片段激活时，添加蛋白激酶C与PS和TPA可降低张力并增加肌球蛋白轻链的蛋白激酶C磷酸化。该证据表明，肌球蛋白轻链的蛋白激酶C磷酸化可能在血管平滑肌收缩中起抑制作用。
