A conserved set of pilin-like molecules controls type IV pilus dynamics and organelle-associated functions in Neisseria gonorrhoeae.
Type IV pili (Tfp) play central roles in prokaryotic cell biology and disease pathogenesis. As dynamic filamentous polymers, they undergo rounds of extension and retraction modelled as pilin subunit polymerization and depolymerization events. Currently, the molecular mechanisms and components influencing Tfp dynamics remain poorly understood. Using Neisseria gonorrhoeae as a model system, we show that mutants lacking any one of a set of five proteins sharing structural similarity to the pilus subunit are dramatically reduced in Tfp expression and that these defects are suppressed in the absence of the PilT pilus retraction protein. Thus, these molecules are not canonical assembly factors but rather act as effectors of pilus homeostasis by promoting extension/polymerization events in the presence of PilT. Furthermore, localization studies support the conclusion that these molecules form a Tfp-associated complex and influence levels of PilC, the epithelial cell adhesin, in Tfp-enriched shear fractions. This is the first time that the step at which individual pilin-like proteins impact on Tfp expression has been defined. The findings have important implications for understanding Tfp dynamics and fundamental Tfp structure/function relationships.
Winther-Larsen
Hanne C
HC
Centre for Molecular Biology and Neuroscience, University of Oslo, 0316 Oslo, Norway.
Wolfgang
Matthew
M
Dunham
Steven
S
van Putten
Jos P M
JP
Dorward
David
D
Løvold
Cecilia
C
Aas
Finn Erik
FE
Koomey
Michael
M
D000595:Amino Acid Sequence; D001422:Bacterial Adhesion; D048430:Cell Shape; D036781:Fimbriae Proteins / Q000235:genetics / Q000378:metabolism*; D010861:Fimbriae, Bacterial / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D006801:Humans; D008969:Molecular Sequence Data; D009344:Neisseria gonorrhoeae / Q000166:cytology* / Q000378:metabolism; D015388:Organelles / Q000378:metabolism*; D016415:Sequence Alignment; D014170:Transformation, Genetic
D036781:Fimbriae Proteins