THE ACTA PROTEIN OF LISTERIA-MONOCYTOGENES ACTS AS A NUCLEATOR INDUCING REORGANIZATION OF THE ACTIN CYTOSKELETON
THE ACTA PROTEIN OF LISTERIA-MONOCYTOGENES ACTS AS A NUCLEATOR INDUCING REORGANIZATION OF THE ACTIN CYTOSKELETON
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DOI：
10.1002/j.1460-2075.1994.tb06318.x
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发表时间：
1994-02-15
期刊：
影响因子：
11.4
通讯作者：
WEHLAND, J
中科院分区：
文献类型：
--
作者：
PISTOR, S;CHAKRABORTY, T;WEHLAND, J
单核细胞增生性李斯特菌是一种兼性细胞内病原体，它利用肌动蛋白和其他微丝相关蛋白在宿主细胞胞浆中移动。缺乏表面结合ActA多肽的单核细胞增多性乳杆菌同基因突变株不再与细胞骨架元件相互作用，因此不能运动(Domann等人，1992，EMBO J.，11,1981-1990；Rock等人，1992，Cell，68,521-531)。为了研究在没有其他细菌因子的情况下ActA与微丝系统的相互作用，在真核细胞中表达了李斯特菌ActA基因。免疫荧光研究表明，完整的ActA，包括其C端定位的细菌膜锚，在转基因细胞中与线粒体共定位。当以线粒体为靶点时，Acta多肽将肌动蛋白和α-肌动蛋白招募到这些细胞器中，并伴随着微丝系统的重组。ActA内部富含脯氨酸的重复区域的移除完全取消了与细胞骨架组件的相互作用。我们的结果确定ActA多肽是肌动蛋白细胞骨架的核因子，并首次提供了对微丝组织中此类控制元件的分子性质的见解。
Listeria monocytogenes, a facultative intracellular pathogen, employs actin and other microfilament-associated proteins to move through the host cell cytoplasm. Isogenic mutants of L.monocytogenes lacking the surface-bound ActA polypeptide no longer interact with cytoskeletal elements and are, as a consequence, non-motile (Domann et al., 1992, EMBO J., 11, 1981-1990; Rocks et al., 1992, Cell, 68, 521-531). To investigate the interaction of ActA with the microfilament system in the absence of other bacterial factors, the listerial actA gene was expressed in eukaryotic cells. Immunofluorescence studies revealed that the complete ActA, including its C-terminally located bacterial membrane anchor, colocalized with mitochondria in transfected cells. When targeted to mitochondria, the ActA polypeptide recruited actin and alpha-actinin to these cellular organelles with concomitant reorganization of the microfilament system. Removal of the internal proline-rich repeat region of ActA completely abrogated interaction with cytoskeletal components. Our results identify the ActA polypeptide as a nucleator of the actin cytoskeleton and provide the first insights into the molecular nature of such controlling elements in microfilament organization.