TY - JOUR
T1 - Flagellar biosynthesis exerts temporal regulation of secretion of specific Campylobacter jejuni colonization and virulence determinants
AU - Barrero-Tobon, Angelica M.
AU - Hendrixson, David R.
PY - 2014/9
Y1 - 2014/9
N2 - Summary: The Campylobacter jejuni flagellum exports both proteins that form the flagellar organelle for swimming motility and colonization and virulence factors that promote commensal colonization of the avian intestinal tract or invasion of human intestinal cells respectively. We explored how the C. jejuni flagellum is a versatile secretory organelle by examining molecular determinants that allow colonization and virulence factors to exploit the flagellum for their own secretion. Flagellar biogenesis was observed to exert temporal control of secretion of these proteins, indicating that a bolus of secretion of colonization and virulence factors occurs during hook biogenesis with filament polymerization itself reducing secretion of these factors. Furthermore, we found that intramolecular and intermolecular requirements for flagellar-dependent secretion of these proteins were most reminiscent to those for flagellin secretion. Importantly, we discovered that secretion of one colonization and virulence factor, CiaI, was not required for invasion of human colonic cells, which counters previous hypotheses for how this protein functions during invasion. Instead, secretion of CiaI was essential for C. jejuni to facilitate commensal colonization of the natural avian host. Our work provides insight into the versatility of the bacterial flagellum as a secretory machine that can export proteins promoting diverse biological processes.
AB - Summary: The Campylobacter jejuni flagellum exports both proteins that form the flagellar organelle for swimming motility and colonization and virulence factors that promote commensal colonization of the avian intestinal tract or invasion of human intestinal cells respectively. We explored how the C. jejuni flagellum is a versatile secretory organelle by examining molecular determinants that allow colonization and virulence factors to exploit the flagellum for their own secretion. Flagellar biogenesis was observed to exert temporal control of secretion of these proteins, indicating that a bolus of secretion of colonization and virulence factors occurs during hook biogenesis with filament polymerization itself reducing secretion of these factors. Furthermore, we found that intramolecular and intermolecular requirements for flagellar-dependent secretion of these proteins were most reminiscent to those for flagellin secretion. Importantly, we discovered that secretion of one colonization and virulence factor, CiaI, was not required for invasion of human colonic cells, which counters previous hypotheses for how this protein functions during invasion. Instead, secretion of CiaI was essential for C. jejuni to facilitate commensal colonization of the natural avian host. Our work provides insight into the versatility of the bacterial flagellum as a secretory machine that can export proteins promoting diverse biological processes.
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U2 - 10.1111/mmi.12711
DO - 10.1111/mmi.12711
M3 - Article
C2 - 25041103
AN - SCOPUS:84906938225
SN - 0950-382X
VL - 93
SP - 957
EP - 974
JO - Molecular Microbiology
JF - Molecular Microbiology
IS - 5
ER -