Departments of Biosciences and Chemistry, Minnesota State University Moorhead, Moorhead, Minnesota 56563, USA.
J Cell Biochem. 2011 Oct;112(10):3025-34. doi: 10.1002/jcb.23227.
The role of phospholipase D (PLD) in cytoskeletal reorganization, ERK activation, and migration is well established. Both isoforms of PLD (PLD1 and PLD2) can independently activate stress fiber formation and increase ERK phosphorylation. However, the isoform's specificity, upstream activators, and downstream targets of PLD that coordinate this process are less well understood. This study explores the role of α(1) -adrenergic receptor stimulation and its effect on PLD activity. We demonstrate that PLD1 activators, RhoA, and PKCα are critical for stress fiber formation and ERK activation, and enhance the production of phosphatidic acid (PA) upon phenylephrine addition. Ectopic expression of dominant negative PLD1 and not PLD2 blocks ERK activation, inhibits stress fiber formation, and reduces cell motility in CCL39 fibroblasts. Furthermore, we demonstrate the mechanism for PLD1 activation of ERK involves Ras. This work indicates that PLD1 plays a novel role mediating growth factor and cell motility events in α(1) -adrenergic receptor-activated cells.
磷脂酶 D（PLD）在细胞骨架重排、ERK 激活和迁移中的作用已得到充分证实。两种 PLD 同工型（PLD1 和 PLD2）都可以独立激活应力纤维形成并增加 ERK 磷酸化。然而，PLD 协调这一过程的同工型特异性、上游激活剂和下游靶标还不太清楚。本研究探讨了α(1) -肾上腺素能受体刺激及其对 PLD 活性的影响。我们证明了 PLD1 激活剂、RhoA 和 PKCα 对于应力纤维形成和 ERK 激活至关重要，并在苯肾上腺素加入时增强了磷酸脂酰肌醇（PA）的产生。显性负 PLD1 的异位表达而非 PLD2 阻断了 ERK 的激活，抑制了应力纤维的形成，并降低了 CCL39 成纤维细胞的迁移能力。此外，我们还证明了 PLD1 激活 ERK 的机制涉及 Ras。这项工作表明，PLD1 在α(1) -肾上腺素能受体激活细胞中发挥了一种新的作用，介导生长因子和细胞迁移事件。
