Bierne Hélène, Miki Hiroaki, Innocenti Metello, Scita Giorgio, Gertler Frank B, Takenawa Tadaomi, Cossart Pascale
Unité des Interactions Bactéries-Cellules, Institut Pasteur, INSERM U604, INRA USC2020, 28 rue du Docteur Roux, 75724 Paris Cedex 15, France.
J Cell Sci. 2005 Apr 1;118(Pt 7):1537-47. doi: 10.1242/jcs.02285. Epub 2005 Mar 15.
Internalisation of the pathogenic bacterium Listeria monocytogenes involves interactions between the invasion protein InlB and the hepatocyte growth factor receptor, Met. Using colocalisation studies, dominant-negative constructs and small interfering RNA (siRNA), we demonstrate a cell-type-dependent requirement for various WASP-related proteins in Listeria entry and InlB-induced membrane ruffling. The WAVE2 isoform is essential for InlB-induced cytoskeletal rearrangements in Vero cells. In HeLa cells, WAVE1, WAVE2 and N-WASP cooperate to promote these processes. Abi1, a key component of WAVE complexes, is recruited at the entry site in both cell types and its inactivation by RNA interference impairs InlB-mediated processes. Ena/VASP proteins also play a role in Listeria internalization, and their deregulation by sequestration or overexpression, modifies actin cups beneath entering particles. Taken together, these results identify the WAVE complex, N-WASP and Ena/VASP as key effectors of the Met signalling pathway and of Listeria entry and highlight the existence of redundant and/or cooperative functions among WASP-family members.
致病性细菌单核细胞增生李斯特菌的内化涉及入侵蛋白InlB与肝细胞生长因子受体Met之间的相互作用。通过共定位研究、显性负性构建体和小干扰RNA（siRNA），我们证明了李斯特菌进入细胞和InlB诱导的膜皱褶过程中，不同WASP相关蛋白对细胞类型有依赖性需求。WAVE2亚型对于InlB诱导的Vero细胞细胞骨架重排至关重要。在HeLa细胞中，WAVE1、WAVE2和N-WASP协同促进这些过程。Abi1是WAVE复合物的关键组成部分，在两种细胞类型的进入位点均被募集，通过RNA干扰使其失活会损害InlB介导的过程。Ena/VASP蛋白在李斯特菌内化过程中也发挥作用，通过隔离或过表达对其进行失调调节会改变进入颗粒下方的肌动蛋白杯。综上所述，这些结果确定了WAVE复合物、N-WASP和Ena/VASP是Met信号通路以及李斯特菌进入细胞过程的关键效应因子，并突出了WASP家族成员之间存在冗余和/或协同功能。
