Elliott Simon J, O'Connell Colin B, Koutsouris Athanasia, Brinkley Carl, Donnenberg Michael S, Hecht Gail, Kaper James B
Center for Vaccine Development and Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
Infect Immun. 2002 May;70(5):2271-7. doi: 10.1128/IAI.70.5.2271-2277.2002.
Disruption of the barrier properties of the enterocyte tight junction is believed to be important in the pathogenesis of diarrhea caused by enteropathogenic Escherichia coli (EPEC). This phenotype can be measured in vitro as the ability of EPEC to reduce transepithelial resistance (TER) across enterocyte monolayers and requires the products of the locus of enterocyte effacement (LEE) and, in particular, the type III secreted effector protein EspF. We report a second LEE-encoded gene that is also necessary for EPEC to fully reduce TER. rorf10 is not necessary for EPEC adherence, EspADB secretion, or formation of attaching and effacing lesions. However, rorf10 mutants have a diminished TER phenotype, reduced intracellular levels of EspF, and a reduced ability to translocate EspF into epithelial cells. The product of rorf10 is a 14-kDa intracellular protein rich in alpha-helices that specifically interacts with EspF but not with Tir or other EPEC secreted proteins. These properties are consistent with the hypothesis that rorf10 encodes a type III secretion chaperone for EspF, and we rename this protein CesF, the chaperone for EPEC secreted protein F.
肠上皮细胞紧密连接的屏障特性破坏被认为在肠致病性大肠杆菌（EPEC）引起的腹泻发病机制中起重要作用。这种表型在体外可通过EPEC降低跨肠上皮细胞单层的跨上皮电阻（TER）的能力来测量，并且需要肠上皮细胞损伤位点（LEE）的产物，特别是III型分泌效应蛋白EspF。我们报告了另一个LEE编码基因，它对于EPEC完全降低TER也是必需的。rorf10对于EPEC黏附、EspADB分泌或黏附并抹去损伤的形成不是必需的。然而，rorf10突变体具有减弱的TER表型、EspF细胞内水平降低以及将EspF转运到上皮细胞中的能力降低。rorf10的产物是一种富含α螺旋的14 kDa细胞内蛋白，它与EspF特异性相互作用，但不与Tir或其他EPEC分泌蛋白相互作用。这些特性与rorf10编码EspF的III型分泌伴侣的假设一致，我们将该蛋白重新命名为CesF，即EPEC分泌蛋白F的伴侣。
