Direct observation of extension and retraction of type IV pili
By Jeffrey M. Skerker, H. Berg. Proceedings of the National Academy of Sciences of the United States of America, 2001
612 citations recorded by the source corpus.
Type IV pili are thin filaments that extend from the poles of a diverse group of bacteria, enabling them to move at speeds of a few tenths of a micrometer per second. They are required for twitching motility, e.g., in Pseudomonas aeruginosa and Neisseria gonorrhoeae, and for social gliding motility in Myxococcus xanthus. Here we report direct observation of extension and retraction of type IV pili in P. aeruginosa. Cells without flagellar filaments were labeled with an amino-specific Cy3 fluorescent dye and were visualized on a quartz slide by total internal reflection microscopy. When pili were attached to a cell and their distal ends were free, they extended or retracted at rates of about 0.5 μm s−1 (29°C). They also flexed by Brownian motion, exhibiting a persistence length of about 5 μm. Frequently, the distal tip of a filament adsorbed to the substratum and the filament was pulled taut. From the absence of lateral deflections of such filaments, we estimate tensions of at least 10 pN. Occasionally, cell bodies came free and were pulled forward by pilus retraction. Thus, type IV pili are linear actuators that extend, attach at their distal tips, exert substantial force, and retract.
Subfields: Genetics, Molecular Biology
View Paper: https://www.semanticscholar.org/paper/1f7cfd3a9a97a62acb5cd0cac12911de73c397d6
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Citations in the corpus
- Quorum sensing and swarming migration in bacteria. (2004, background): “aeruginosa is a gram-negative bacterium that contains a single polar flagellum and several type IV pili [80], living in soil and aqueous environments.”
- Average nutrient uptake by a self-propelled unsteady squirmer (2005, background): “…have functional slimeextruding pores and helical fibrils on their surface for screw thread gliding (Hoiczyk & Baumeister 1995; Hoiczyk 2000), while Synechocystis (Skerker & Berg 2001) and Myxococcus (Wall & Kaiser 1999) use tentacle-like organelles (type IV pili) for social gliding.”
- DNA uptake during bacterial transformation (2004, background): “T4P function in bacterial cell-to-cell interactions, adhesion to host cells and twitching motility — a form of locomotion that is powered by extension and retraction of the pilus filamen”
- Nutrient Uptake by a Self‐Propelled Steady Squirmer (2003, background): “Skerker and Berg (6) h averecently made direct observations of extension and contraction of some elements localized on the surface of certain cyanobacteria, but only at the tail of the microorganism.”
- Crystal structures of the pilus retraction motor PilT suggest large domain movements and subunit cooperation drive motility. (2007, background): “Introduction Type IV pili are grappling lines that extend from bacterial cells to solid substrates to be subsequently reeled in by membrane-associated motors, thereby promoting motility on surfaces (Merz et al., 2000;Skerker and Berg, 2001).”
- Signals, Regulatory Networks, and Materials That Build and Break Bacterial Biofilms (2009, background): “Although not all types of pili have been demonstrated to be retractable, many types of pili are able to retract against great force (209, 225, 294).”
- Type IV pilus structure and bacterial pathogenicity (2004, background): “Surface motility involves pilus retraction, where the pili attach nonspecifically to mucosal surfaces and are retracted into the bacterium, thereby pulling the cells alon”
- Biofilm formation by Pseudomonas aeruginosa wild type, flagella and type IV pili mutants (2003, background): “The surface-associated so-called twitching motility is powered by extension and retraction of type IV pili (Skerker and Berg, 2001).”