ADF/Cofilin controls cell polarity during fibroblast migration
ADF/Cofilin controls cell polarity during fibroblast migration
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DOI：
10.1016/s0960-9822(03)00040-x
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发表时间：
2003-02-04
期刊：
影响因子：
9.2
通讯作者：
Cramer, LP
中科院分区：
文献类型：
--
作者：
Dawe, HR;Minamide, LS;Cramer, LP
为了迁移，正常情况下细胞必须建立形态极性，并连续突出单个板状伪足，在迁移方向上极化。我们以前已经表明，肌动蛋白丝拆卸是必要的突出的板状伪足成纤维细胞迁移。由于ADF/cofilin（AC）蛋白是催化细胞中细丝解体所必需的，我们评估了它们在迁移成纤维细胞中极化板状伪足突出中的作用。我们比较了AC和非活性的磷酸化AC（pAC）在迁移细胞中的空间分布。AC，而不是pAC，定位于板状伪足。为了研究AC在细胞极性中的作用，我们通过过表达组成型活性（CA）LIM激酶1来增加迁移成纤维细胞中pAC的比例。在87%表达CA LIM激酶的细胞中，细胞极性被消除。在这样的细胞中，单一的极化板状伪足被多个非极化的板状伪足所取代，与非表达迁移细胞相反，pAC染色。通过共表达活性的、不可磷酸化的爪蟾AC（CA XAC）与CA LIMK来拯救细胞极性。此外，过度表达假磷酸化（活性较低）XAC本身也消除了细胞极性。我们的结论是，局部维持ADF/cofilin在活跃的，nonphosphorylated状态内的板状伪足是必要的，以保持极化突起细胞迁移过程中。
To migrate, normally a cell must establish morphological polarity and continuously protrude a single lamellipodium, polarized in the direction of migration. We have previously shown that actin filament disassembly is necessary for protrusion of the lamellipodium during fibroblast migration. As ADF/cofilin (AC) proteins are essential for the catalysis of filament disassembly in cells, we assessed their role in polarized lamellipodium protrusion in migrating fibroblasts. We compared the spatial distribution of AC and the inactive, phosphorylated AC (pAC) in migrating cells. AC, but not pAC, localized to the lamellipodium. To investigate a role for AC in cell polarity, we increased the proportion of pAC in migrating fibroblasts by overexpressing constitutively active (CA) LIM kinase 1. In 87% of cells expressing CA LIM kinase, cell polarity was abolished. In such cells, the single polarized lamellipodium was replaced by multiple nonpolarized lamellipodia, which, in contrast to nonexpressing migrating cells, stained for pAC. Cell polarity was rescued by coexpressing an active, nonphosphorylatable Xenopus AC (CA XAC) with the CA LIMK. Furthermore, overexpressing a pseudophosphorylated (less active) XAC by itself also abolished cell polarity. We conclude that locally maintaining ADF/cofilin in the active, nonphosphorylated state within the lamellipodium is necessary to maintain polarized protrusion during cell migration.