Role of actin-filament disassembly in lamellipodium protrusion in motile cells revealed using the drug jasplakinolide
Role of actin-filament disassembly in lamellipodium protrusion in motile cells revealed using the drug jasplakinolide
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DOI：
10.1016/s0960-9822(99)80478-3
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发表时间：
1999-10-07
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：
Cramer, LP
背景资料：在运动细胞中，片状伪足（一种细胞边缘）的突出需要肌动蛋白单体在片状伪足的尖端组装成肌动蛋白丝。肌动蛋白丝分解在这一过程中的重要性还不太清楚，在这里使用肌动蛋白药物jasplakinaldehyde进行评估，jasplakinaldehyde具有两种已知的活性-抑制丝分解和诱导肌动蛋白聚合物的增加。1 μ M的茉莉花激酶可渗透细胞，结合细胞丝状肌动蛋白（F-actin），并在3.5分钟内抑制丝状肌动蛋白的解体，但直到60分钟才检测到肌动蛋白聚合物的显着增加。在活的透化细胞中，jasplakinastatin并不抑制丝装配从供应，纯化的肌动蛋白单体。在迁移的鸡成纤维细胞，板状伪足突起被阻止在1-5分钟的治疗与1 μ M jasplakinidine，没有任何干扰肌动蛋白组织。在非迁移的鸡成纤维细胞，有一个延迟;在发病的jasplakinolide诱导抑制板状伪足突起，在此期间，板状伪足长度线性增加，没有增加的突起率。在感染的PtK 2细胞中的李斯特菌的运动性降低了2.3倍，在3分钟内与1 μ M的jasplakinasthen.Conclusions：肌动蛋白丝拆卸紧密耦合到板状伪足突起迁移鸡成纤维细胞和李斯特菌在PtK 2细胞的运动性。这些数据的一个简单的解释是，正在进行的肌动蛋白丝组装使用游离肌动蛋白单体来自丝拆卸，优先于存储的单体的情况。
Background: In motile cells, protrusion of the lamellipodium (a type of cell margin) requires assembly of actin monomers into actin filaments at the tip of the lamellipodium. The importance of actin-filament disassembly in this process is less well understood, and is assessed here using the actin drug jasplakinolide, which has two known activities - inhibition of filament disassembly and induction of an increase in actin polymer.Results: in cells the two activities of jasplakinolide were found to be separable; 1 mu M jasplakinolide could permeate cells, bind cellular filamentous actin (F-actin) and inhibit filament disassembly within 3.5 minutes, but significant increase in actin polymer was not detected until 60 minutes of treatment. In live, permeabilised cells, jasplakinolide did not inhibit filament assembly from supplied, purified actin monomers. In migrating chick fibroblasts, lamellipodium protrusion was blocked within 1-5 minutes of treatment with 1 mu M jasplakinolide, without any perturbation of actin organisation. In non-migrating chick fibroblasts, there was a delay;in the onset of jasplakinolide-induced inhibition of lamellipodium protrusion, during which lamellipodium length increased linearly with no increase in protrusion rate. Motility of the bacterium Listeria in infected PtK2 cells was reduced 2.3-fold within 3 minutes of treatment with 1 mu M jasplakinolide.Conclusions: Actin-filament disassembly is tightly coupled to lamellipodium protrusion in migrating chick fibroblasts and motility of Listeria in PtK2 cells. One simple interpretation of these data is a situation whereby ongoing actin-filament assembly uses free actin monomer derived from filament disassembly, in preference to stored monomer.