Type III Protein Secretion in Yersinia Species

The type III mechanism of protein secretion is a pathogenic strategy shared by a number of gram-negative pathogens of plants and animals that has evolved in order to inject virulence proteins into the cytosol of target eukaryotic cells. The pathogens of the Yersinia genus represent a model system where much progress has been made in understanding this secretion pathway. Herein, we review what has been recently learned in yersiniae about the various environmental signals that induce type III secretion, how the synthesis of secretion substrates is regulated, and how such a diverse group of proteins is recognized as a substrate for secretion.