A multinucleating Escherichia coli cytotoxin perturbs cell cycle in cultured epithelial cells

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• 作者：A. Giamboi-Miraglia ; S. Travaglione ; P. Filippini ; A. Fabbri ; C. Fiorentini ; L. Falzano
• 关键词：CNF1 ; Cell cycle ; Epithelial cells
• 刊名：Toxicology in Vitro
• 出版年：2007
• 出版时间：March 2007
• 年：2007
• 卷：21
• 期：2
• 页码：235-239
• 全文大小：432 K

文摘

Pathogenic Escherichia coli strains produce a number of virulence-associated factors, among which cytotoxic necrotizing factor 1 (CNF1). CNF1 is a chromosomally encoded toxin that permanently activates the small GTP-binding proteins of the Rho family (Rho, Rac and Cdc42) by catalizing their deamidation at a specific glutamine residue. This activation modulates a high number of cellular functions, including the reorganization of the actin cytoskeleton, the promotion of cell spreading and the multinucleation. Indeed, accumulating evidence indicates that, in addition to the well-characterized Ras GTPases, also Rho family proteins are crucial in different points of cell cycle regulation.

Here, we report that CNF1 induces a block of the cell cycle at the G₂/M transition in epithelial cell line HEp-2, and up-regulates cyclin B1 and p53 proteins confining them in the cytoplasm region. The ability of CNF1 to perturb cell cycle progression could play a role in E. coli pathogenicity.