Interaction of the Salmonella-containing vacuole with the endocytic recycling system.
Upon entry of the pathogen Salmonella enterica serovar Typhimurium into host cells, the majority of bacteria reside in a membrane-bound compartment called the Salmonella-containing vacuole (SCV). Previous studies have established that the SCV transiently interacts with early endosomes but only acquires a subset of late endosomal/lysosomal proteins. However, the complete set of interactions between the SCV and the endocytic machinery has yet to be characterized. In this study, we have shown that four characterized regulators of endocytic recycling were present on the SCV after invasion. Interaction kinetics were different for each of the regulators; ARF6 and Rab4 associated immediately, but their presence was diminished 60 min post-infection, whereas syntaxin13 and Rab11 association peaked at 60 min. Using a dominant negative approach, we determined that Rab11 regulates the recycling of CD44 from the vacuole but had no effect on major histocompatibility complex (MHC) class I recycling. In contrast, syntaxin13 regulated the recycling of MHC class I but not of CD44. We also determined that maturation of the SCV, measured by the acquisition of lysosomal associated membrane protein-1, slowed when recycling was impaired. These findings suggest that protein movement through the endocytic recycling system is regulated through at least two concurrent pathways and that efficient interaction with these pathways is necessary for maturation of the Salmonella-containing vacuole. We also demonstrate the utility of using Salmonella invasion as a model of endosomal recycling events.
Smith
Adam C
AC
Infection, Immunity, Injury, and Repair Program, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada.
Cirulis
Judith T
JT
Casanova
James E
JE
Scidmore
Marci A
MA
Brumell
John H
JH
D000089982:ADP-Ribosylation Factor 6; D020727:ADP-Ribosylation Factors / Q000737:chemistry; D015703:Antigens, CD / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism; D005799:Genes, Dominant; D005805:Genes, MHC Class I; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D018960:Hyaluronan Receptors / Q000096:biosynthesis / Q000737:chemistry; D007700:Kinetics; D051907:Lysosomal Membrane Proteins; D008247:Lysosomes / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D008856:Microscopy, Fluorescence; D010957:Plasmids / Q000378:metabolism; D011485:Protein Binding; D050765:Qa-SNARE Proteins; D012475:Salmonella / Q000378:metabolism*; D012480:Salmonella Infections / Q000473:pathology; D012486:Salmonella typhimurium / Q000378:metabolism; D013997:Time Factors; D014162:Transfection; D014617:Vacuoles / Q000737:chemistry*; D020695:rab4 GTP-Binding Proteins / Q000737:chemistry
D000089982:ADP-Ribosylation Factor 6; D015703:Antigens, CD; D018960:Hyaluronan Receptors; D051907:Lysosomal Membrane Proteins; D008565:Membrane Proteins; D050765:Qa-SNARE Proteins; D049452:Green Fluorescent Proteins; D020727:ADP-Ribosylation Factors; C000715348:ARF6 protein, human; D020695:rab4 GTP-Binding Proteins