A new pathway for the secretion of virulence factors by bacteria: the flagellar export apparatus functions as a protein-secretion system.
Biogenesis of the flagellum, a motive organelle of many bacterial species, is best understood for members of the Enterobacteriaceae. The flagellum is a heterooligomeric structure that protrudes from the surface of the cell. Its assembly initially involves the synthesis of a dedicated protein export apparatus that subsequently transports other flagellar proteins by a type III mechanism from the cytoplasm to the outer surface of the cell, where oligomerization occurs. In this study, the flagellum export apparatus was shown to function also as a secretion system for the transport of several extracellular proteins in the pathogenic bacterium Yersinia enterocolitica. One of the proteins exported by the flagellar secretion system was the virulence-associated phospholipase, YplA. These results suggest type III protein secretion by the flagellar system may be a general mechanism for the transport of proteins that influence bacterial-host interactions.
Young
G M
GM
Department of Molecular Microbiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Schmiel
D H
DH
Miller
V L
VL
D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000096:biosynthesis; D004755:Enterobacteriaceae / Q000472:pathogenicity* / Q000502:physiology*; D005407:Flagella / Q000502:physiology*; D005798:Genes, Bacterial; D009068:Movement / Q000187:drug effects / Q000502:physiology; D016296:Mutagenesis; D010740:Phospholipases / Q000235:genetics / Q000378:metabolism*; D018085:Regulon; D014774:Virulence; D015008:Yersinia enterocolitica / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D010740:Phospholipases