Boland A, Sory M P, Iriarte M, Kerbourch C, Wattiau P, Cornelis G R
Microbial Pathogenesis Unit, International Institute of Cellular and Molecular Pathology and Faculté de Médecine, Université Catholique de Louvain, Brussels, Belgium.
EMBO J. 1996 Oct 1;15(19):5191-201.
The Yersinia Yop virulon is an anti-host system made up of four elements: (i) a type III secretion system called Ysc; (ii) a system designed to deliver bacterial proteins into eukaryotic target cells (YopB, YopD); (iii) a control element (YopN); and (iv) a set of intracellularly delivered proteins designed to disarm these cells or disrupt their communications (YopE, YopH and possibly others). YopM, another Yop protein, binds thrombin and is thus presumed to act as an extracellular effector. Here, we analyzed YopM from Y.enterocolitica and we wondered whether it could also be delivered inside eukaryotic cells. To answer this question we applied the Yop-Cya reporter strategy. Hybrids made of 141 or 100 N-terminal residues of YopM fused to Cya were delivered inside PU5-1.8 macrophages by recombinant Y.enterocolitica strains. YopB and YopD were required as translocators. Leakage of the reporters into the macrophage culture supernatant during the bacterial infection increased strongly when YopN was missing, showing that YopN is involved in the control of delivery of YopM inside eukaryotic cells. YopN itself was not delivered into the macrophages. In conclusion, YopM is translocated inside the eukaryotic cells and its physiopathological role should be revised or completed.
耶尔森氏菌的Yop毒力蛋白分泌系统是一种由四个元件组成的抗宿主系统：（i）一种名为Ysc的III型分泌系统；（ii）一种将细菌蛋白递送至真核靶细胞的系统（YopB、YopD）；（iii）一个控制元件（YopN）；以及（iv）一组旨在解除这些细胞武装或破坏其通讯的细胞内递送蛋白（YopE、YopH以及可能的其他蛋白）。另一种Yop蛋白YopM可结合凝血酶，因此被推测作为一种细胞外效应物发挥作用。在此，我们分析了小肠结肠炎耶尔森氏菌的YopM，并想知道它是否也能被递送至真核细胞内部。为回答这个问题，我们应用了Yop-Cya报告策略。由YopM的141个或100个N端残基与Cya融合而成的杂种蛋白，通过重组小肠结肠炎耶尔森氏菌菌株被递送至PU5-1.8巨噬细胞内部。YopB和YopD作为转运蛋白是必需的。当缺少YopN时，在细菌感染期间报告蛋白泄漏至巨噬细胞培养上清液中的情况显著增加，这表明YopN参与了YopM在真核细胞内递送的控制。YopN自身并未被递送至巨噬细胞内。总之，YopM可转运至真核细胞内部，其生理病理作用应予以修正或补充。
