Spatial regulation of the cAMP-dependent protein kinase during chemotactic cell migration
Spatial regulation of the cAMP-dependent protein kinase during chemotactic cell migration
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DOI：
10.1073/pnas.0507072102
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发表时间：
2005-10-04
影响因子：
11.1
通讯作者：
Hogan, BP
中科院分区：
文献类型：
--
作者：
Howe, AK;Baldor, LC;Hogan, BP
从历史上看，camp依赖性蛋白激酶（PKA）在细胞运动中具有矛盾的作用，已被证明可以促进和抑制肌动蛋白细胞骨架动力学和细胞迁移。为了理解这种二分法，我们在这里展示了PKA在细胞迁移过程中在亚细胞空间受到调节。免疫荧光显微镜和伪足生化富集显示，趋化过程中形成的突起细胞结构中富集了PKA II型调控亚基和PKA活性。这种富集与PKA关键细胞骨架底物磷酸化增加有关，包括血管扩张剂刺激磷酸化蛋白（VASP）和含有PEST基元的蛋白酪氨酸磷酸酶。重要的是，抑制PKA活性或其与A激酶锚定蛋白相互作用的能力抑制了假足内Rac GTPase的活性。这种效应与鸟嘌呤核苷交换因子活性降低和GTPase激活蛋白活性增加有关。最后，抑制PKA锚定，就像抑制PKA总活性一样，抑制假足的形成和趋化细胞的迁移。这些数据表明，PKA通过锚定的空间调节是正常趋化细胞运动的一个重要方面。
Historically, the cAMP-dependent protein kinase (PKA) has a paradoxical role in cell motility, having been shown to both facilitate and inhibit actin cytoskeletal dynamics and cell migration. In an effort to understand this dichotomy, we show here that PKA is regulated in subcellular space during cell migration. Immunofluorescence microscopy and biochemical enrichment of pseudopodia showed that type II regulatory subunits of PKA and PKA activity are enriched in protrusive cellular structures formed during chemotaxis. This enrichment correlates with increased phosphorylation of key cytoskeletal substrates for PKA, including the vasodilator-stimulated phosphoprotein (VASP) and the protein tyrosine phosphatase containing a PEST motif. Importantly, inhibition of PKA activity or its ability to interact with A kinase anchoring proteins inhibited the activity of the Rac GTPase within pseudopodia. This effect correlated with both decreased guanine nucleoticle exchange factor activity and increased GTPase activating protein activity. Finally, inhibition of PKA anchoring, like inhibition of total PKA activity, inhibited pseudopod formation and chemotactic cell migration. These data demonstrate that spatial regulation of PKA via anchoring is an important facet of normal chemotactic cell movement.