Selective Inhibition of Type III Secretion Activated Signaling by the Salmonella Effector AvrA

PLoS Pathogens

Fangyong Du¹  Jorge E. Galán¹ 

[1] Section of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, United States of America

关键词: Salmonella typhimurium;    Phosphorylation;    Saccharomyces cerevisiae;    Salmonellosis;    Salmonella;    Transcription factors;    Gastrointestinal tract;    c-Jun N-terminal kinase signaling cascade;   

DOI  :  10.1371/journal.ppat.1000595

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

Salmonella enterica utilizes a type III secretion system (TTSS) encoded in its pathogenicity island 1 to mediate its initial interactions with intestinal epithelial cells, which are characterized by the stimulation of actin cytoskeleton reorganization and a profound reprogramming of gene expression. These responses result from the stimulation of Rho-family GTPases and downstream signaling pathways by specific effector proteins delivered by this TTSS. We show here that AvrA, an effector protein of this TTSS, specifically inhibits the Salmonella-induced activation of the JNK pathway through its interaction with MKK7, although it does not interfere with the bacterial infection-induced NF-κB activation. We also show that AvrA is phosphorylated at evolutionary conserved residues by a TTSS-effector-activated ERK pathway. This interplay between effector proteins delivered by the same TTSS highlights the remarkable complexity of these systems.

【 授权许可】

CC BY