Interaction of Ipa proteins of Shigella flexneri with alpha5beta1 integrin promotes entry of the bacteria into mammalian cells.
Interaction of Ipa proteins of Shigella flexneri with alpha5beta1 integrin promotes entry of the bacteria into mammalian cells.
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DOI：
10.1084/jem.183.3.991
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发表时间：
1996-03-01
影响因子：
15.3
通讯作者：
Sasakawa, C
中科院分区：
文献类型：
--
作者：
Watarai, M;Funato, S;Sasakawa, C
志贺氏菌是引起人类细菌性痢疾的高度适应性细菌病原体属。到达结肠的细菌通过由志贺氏菌的Ipa蛋白介导的细菌定向内吞作用侵入肠上皮细胞：IpaB， IpaC和IpaD。上皮细胞的侵袭被认为是一种受体介导的现象，尽管与Ipa蛋白相互作用的宿主细胞成分尚未被确定。我们在此报道了在福氏志贺氏菌侵袭系统和中国仓鼠卵巢（CHO）细胞单层中，Ipa蛋白能够直接与alpha5beta1整合素相互作用。随着α 5beta1整合素水平的升高，福氏梭菌对CHO细胞的侵袭能力增强。当flexneri感染CHO细胞时，整合素调控的125k黏附激酶pp125fak和paxillin的酪氨酸磷酸化均受到刺激。相比之下，由于其spa32基因突变而导致入侵缺陷的flexneri等基因菌株未能诱导这种磷酸化。在体外和体内条件下，释放的IpaB、IpaC和IpaD蛋白与α 5 β 1整合素的结合方式与可溶性纤维连接蛋白不同，但与纤维连接蛋白的组织形式相似。在flexneri与CHO细胞的附着位点，alpha5beta1整合素与肌动蛋白聚合聚合。因此，这些数据表明Ipa蛋白与α 5beta1整合素相互作用的能力可能是触发肌动蛋白细胞骨架重组的重要志贺氏菌因子。
Shigella is a genus of highly adapted bacterial pathogens that cause bacillary dysentery in humans. Bacteria reaching the colon invade intestinal epithelial cells by a process of bacterial-directed endocytosis mediated by the Ipa proteins: IpaB, IpaC, and IpaD of Shigella. The invasion of epithelial cells is thought to be a receptor- mediated phenomenon, although the cellular components of the host that interact with the Ipa proteins have not yet been identified. We report here that in a Shigella flexneri invasive system and Chinese hamster ovary (CHO) cell monolayers, the Ipa proteins were capable of interacting directly with alpha5beta1 integrin. The invasive capacity of S. flexneri for CHO cells increased as levels of alpha5beta1 integrin were elevated. When CHO cells were infected with S. flexneri, the tyrosine phosphorylation both of pp 125FAK, an integrin-regulated 125 K focal adhesion kinase, and of paxillin was stimulated. In contrast, an isogenic strain of S. flexneri that was defective in invasion owing to a mutation in its spa32 gene failed to induce such phosphorylation. Under in vitro and in vivo conditions, the released IpaB, IpaC, and IpaD proteins bound to alpha 5 beta 1 integrin in a manner different from that of soluble fibronectin but similar to that of the tissue form of fibronectin. At the site of attachment of S. flexneri to CHO cells, alpha5beta1 integrin converged with polymerization of actin. These data thus suggest that the capacity of Ipa proteins to interact with alpha5beta1 integrin may be an important Shigella factor in triggering the reorganization of actin cytoskeletons.
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DOI：
10.1073/pnas.89.13.5976
发表时间：
1992-07-01
影响因子：
11.1
作者：
GINOCCHIO, C;PACE, J;GALAN, JE
通讯作者：
GALAN, JE
影响因子：
64.5
作者：
ISBERG, RR;LEONG, JM
通讯作者：
LEONG, JM
影响因子：
3.1
作者：
ROSENSHINE, I;DURONIO, V;FINLAY, BB
通讯作者：
FINLAY, BB
影响因子：
3.2
作者：
SASAKAWA, C;KOMATSU, K;YOSHIKAWA, M
通讯作者：
YOSHIKAWA, M
影响因子：
56.9
作者：
MIYAMOTO, S;AKIYAMA, SK;YAMADA, KM
通讯作者：
YAMADA, KM