Relationship between paxillin and myosin phosphorylation during muscarinic stimulation of smooth muscle.
Relationship between paxillin and myosin phosphorylation during muscarinic stimulation of smooth muscle.
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DOI：
10.1152/ajpcell.1998.274.3.c741
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发表时间：
1998-03
期刊：
影响因子：
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通讯作者：
Dolly Mehta;Zhonglin Wang;M. Wu;S. Gunst
中科院分区：
文献类型：
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作者：
Dolly Mehta;Zhonglin Wang;M. Wu;S. Gunst
在气管平滑肌收缩过程中，桩蛋白的酪氨酸磷酸化增加与力的发展相关，表明桩蛋白在平滑肌的收缩激活中起作用[Z. L. Wang，F. M. Pavalko和S. J. Gunst Am. J.Physiol.271（Cell Physiol.40）：C1594-C1602，1996]。我们比较了Ca 2+敏感性的酪氨酸磷酸化的桩蛋白和肌球蛋白轻链（MLC）磷酸化在气管肌肉和评估是否MLC磷酸化是必要的诱导桩蛋白磷酸化。用10-7-10- 4 M乙酰胆碱（ACh）在0、0.05、0.1或0.5 mM细胞外Ca 2+中刺激Ca 2+耗尽的肌条。在细胞外钙离子的情况下，10-4 M ACh诱导桩蛋白磷酸化的最大增加，而不增加MLC磷酸化或力。细胞外Ca 2+浓度的增加没有进一步增加桩蛋白磷酸化。然而，在10-6 M ACh刺激，桩蛋白磷酸化增加细胞外Ca 2+浓度的增加。我们的结论是，桩蛋白的酪氨酸磷酸化可以刺激信号通路，不依赖于Ca 2+动员和收缩蛋白的激活是不需要引起桩蛋白磷酸化。
The tyrosine phosphorylation of paxillin increases in association with force development during tracheal smooth muscle contraction, suggesting that paxillin plays a role in the contractile activation of smooth muscle [Z. L. Wang, F. M. Pavalko, and S. J. Gunst. Am. J. Physiol. 271 ( Cell Physiol. 40): C1594-C1602, 1996]. We compared the Ca2+ sensitivity of the tyrosine phosphorylation of paxillin and myosin light chain (MLC) phosphorylation in tracheal muscle and evaluated whether MLC phosphorylation is necessary to induce paxillin phosphorylation. Ca2+-depleted muscle strips were stimulated with 10-7-10-4M acetylcholine (ACh) in 0, 0.05, 0.1, or 0.5 mM extracellular Ca2+. In the absence of extracellular Ca2+, 10-4 M ACh induced a maximal increase in paxillin phosphorylation without increasing MLC phosphorylation or force. Increases in extracellular Ca2+ concentration did not further increase paxillin phosphorylation. However, during stimulation with 10-6 M ACh, paxillin phosphorylation increased with increases in extracellular Ca2+ concentration. We conclude that the tyrosine phosphorylation of paxillin can be stimulated by signaling pathways that do not depend on Ca2+ mobilization and that the activation of contractile proteins is not required to elicit paxillin phosphorylation.