The QseC Adrenergic Signaling Cascade in Enterohemorrhagic E. coli (EHEC)

PLoS Pathogens

Vanessa Sperandio¹  David A. Rasko²  Marcie B. Clarke²  David T. Hughes³  Kaneyoshi Yamamoto³ 

[1] Department of Agricultural Chemistry, Kinki University, Nakamachi, Nara, Japan;Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America;Department of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America

关键词: Epinephrine;    Gene expression;    Gene regulation;    Phosphorylation;    Hormone receptor signaling;    Norepinephrine;    Stress signaling cascade;    Flagella;   

DOI  :  10.1371/journal.ppat.1000553

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

The ability to respond to stress is at the core of an organism's survival. The hormones epinephrine and norepinephrine play a central role in stress responses in mammals, which require the synchronized interaction of the whole neuroendocrine system. Mammalian adrenergic receptors are G-coupled protein receptors (GPCRs); bacteria, however, sense these hormones through histidine sensor kinases (HKs). HKs autophosphorylate in response to signals and transfer this phosphate to response regulators (RRs). Two bacterial adrenergic receptors have been identified in EHEC, QseC and QseE, with QseE being downstream of QseC in this signaling cascade. Here we mapped the QseC signaling cascade in the deadly pathogen enterohemorrhagic E. coli (EHEC), which exploits this signaling system to promote disease. Through QseC, EHEC activates expression of metabolic, virulence and stress response genes, synchronizing the cell response to these stress hormones. Coordination of these responses is achieved by QseC phosphorylating three of the thirty-two EHEC RRs. The QseB RR, which is QseC's cognate RR, activates the flagella regulon which controls bacteria motility and chemotaxis. The QseF RR, which is also phosphorylated by the QseE adrenergic sensor, coordinates expression of virulence genes involved in formation of lesions in the intestinal epithelia by EHEC, and the bacterial SOS stress response. The third RR, KdpE, controls potassium uptake, osmolarity, and also the formation of lesions in the intestine. Adrenergic regulation of bacterial gene expression shares several parallels with mammalian adrenergic signaling having profound effects in the whole organism. Understanding adrenergic regulation of a bacterial cell is a powerful approach for studying the underlying mechanisms of stress and cellular survival.

【 授权许可】

CC BY