RfaL Is Required for Yersinia pestis Type III Secretion and Virulence

• DOI: 10.1128/iai.01417-12
• Publication Date: 2013-01-29T02:27:29Z
• Authors: Andrew S. Houppert; Lesley Bohman; Peter M. Merritt; Christopher B. Cole; Adam J. Caulfield; Wyndham W. Lathem; Melanie M. Marketon
• Keywords: Yersinia pestis; Virulence factor

Yersinia pestis, the causative agent of plague, uses a type III secretion system (T3SS) to inject cytotoxic Yop proteins directly into cytosol mammalian host cells. The T3SS can also be activated in vitro at 37°C absence calcium. chromosomal gene rfaL (waaL) was recently identified as virulence factor required for proper function T3SS. RfaL functions ligase that adds terminal N-acetylglucosamine lipooligosaccharide core Y. pestis. We previously showed deletion prevents Yops vitro. Here we show divalent cations calcium, strontium, and magnesium partially or fully rescue vitro, indicating phenotype mutant may due structural changes outer membrane corresponding feedback inhibition on In support this, found defect overcome by deleting regulatory lcrQ. Consistent with defective T3SS, is less virulent than wild type. here correlates decrease both expression ability innate immune cells, combined an increased sensitivity cationic antimicrobial peptides.