Li Jia, Wang Ruping, Gannon Olivia J, Rezey Alyssa C, Jiang Sixin, Gerlach Brennan D, Liao Guoning, Tang Dale D
From the Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York 12208.
From the Department of Molecular and Cellular Physiology, Albany Medical College, Albany, New York 12208
J Biol Chem. 2016 Nov 4;291(45):23693-23703. doi: 10.1074/jbc.M116.749341. Epub 2016 Sep 23.
Polo-like kinase 1 (Plk1) is a serine/threonine-protein kinase that has been implicated in mitosis, cytokinesis, and smooth muscle cell proliferation. The role of Plk1 in smooth muscle contraction has not been investigated. Here, stimulation with acetylcholine induced Plk1 phosphorylation at Thr-210 (an indication of Plk1 activation) in smooth muscle. Contractile stimulation also activated Plk1 in live smooth muscle cells as evidenced by changes in fluorescence resonance energy transfer signal of a Plk1 sensor. Moreover, knockdown of Plk1 in smooth muscle attenuated force development. Smooth muscle conditional knock-out of Plk1 also diminished contraction of mouse tracheal rings. Plk1 knockdown inhibited acetylcholine-induced vimentin phosphorylation at Ser-56 without affecting myosin light chain phosphorylation. Expression of T210A Plk1 inhibited the agonist-induced vimentin phosphorylation at Ser-56 and contraction in smooth muscle. However, myosin light chain phosphorylation was not affected by T210A Plk1. Ste20-like kinase (SLK) is a serine/threonine-protein kinase that has been implicated in spindle orientation and microtubule organization during mitosis. In this study knockdown of SLK inhibited Plk1 phosphorylation at Thr-210 and activation. Finally, asthma is characterized by airway hyperresponsiveness, which largely stems from airway smooth muscle hyperreactivity. Here, smooth muscle conditional knock-out of Plk1 attenuated airway resistance and airway smooth muscle hyperreactivity in a murine model of asthma. Taken together, these findings suggest that Plk1 regulates smooth muscle contraction by modulating vimentin phosphorylation at Ser-56. Plk1 activation is regulated by SLK during contractile activation. Plk1 contributes to the pathogenesis of asthma.
Polo样激酶1（Plk1）是一种丝氨酸/苏氨酸蛋白激酶，与有丝分裂、胞质分裂和平滑肌细胞增殖有关。尚未研究Plk1在平滑肌收缩中的作用。在此，乙酰胆碱刺激可诱导平滑肌中Plk1在苏氨酸210位点磷酸化（这是Plk1激活的标志）。收缩刺激也能在活的平滑肌细胞中激活Plk1，这可通过Plk1传感器的荧光共振能量转移信号变化得到证实。此外，平滑肌中Plk1的敲低会减弱力量的产生。平滑肌条件性敲除Plk1也会减少小鼠气管环的收缩。Plk1敲低抑制了乙酰胆碱诱导的波形蛋白在丝氨酸56位点的磷酸化，而不影响肌球蛋白轻链的磷酸化。T210A Plk1的表达抑制了激动剂诱导的波形蛋白在丝氨酸56位点的磷酸化和平滑肌收缩。然而，肌球蛋白轻链的磷酸化不受T210A Plk1的影响。Ste20样激酶（SLK）是一种丝氨酸/苏氨酸蛋白激酶，与有丝分裂期间的纺锤体定向和微管组织有关。在本研究中，SLK的敲低抑制了Plk1在苏氨酸210位点的磷酸化和激活。最后，哮喘的特征是气道高反应性，这在很大程度上源于气道平滑肌的高反应性。在此，平滑肌条件性敲除Plk1可减轻哮喘小鼠模型中的气道阻力和气道平滑肌高反应性。综上所述，这些发现表明Plk1通过调节波形蛋白在丝氨酸56位点的磷酸化来调节平滑肌收缩。在收缩激活过程中，Plk1的激活受SLK调节。Plk1参与了哮喘的发病机制。
