TY - JOUR
T1 - Contact-induced apical asymmetry drives the thigmotropic responses of Candida albicans hyphae
AU - Thomson, Darren D
AU - Wehmeier, Silvia
AU - Byfield, FitzRoy J
AU - Janmey, Paul A
AU - Caballero-Lima, David
AU - Crossley, Alison
AU - Brand, Alexandra C
N1 - Acknowledgements
We thank Marco Thiel for assistance with data interpretation, Peter Sudbery for the provision of strains and Jeremy Craven for useful discussions. This work was supported by a BBSRC-DTG to D. D. T., NIH award DK083592 to F. J. B. and P. A. J., and a Royal Society URF UF080611 and MRC NIRG 90671 to A. C. B.
PY - 2015/3
Y1 - 2015/3
N2 - Filamentous hyphae of the human pathogen, Candida albicans, invade mucosal layers and medical silicones. In vitro, hyphal tips re-orient thigmotropically on contact with small obstacles. It is not known how surface topography is sensed but hyphae lacking the cortical marker, Rsr1/Bud1, are unresponsive. We show that, on surfaces, the morphology of hyphal tips and the position of internal polarity-protein complexes are asymmetrically skewed towards the substratum, and biased towards the softer of two surfaces. In nano-fabricated chambers, the Spitzenkörper (Spk) responded to touch by translocating across the apex towards the point of contact, where its stable maintenance correlated with contour-following growth. In the rsr1Δ mutant, the position of the Spk meandered and these responses were attenuated. Perpendicular collision caused lateral Spk oscillation within the tip until after establishment of a new growth axis, suggesting Spk position does not predict the direction of growth in C. albicans. Acute tip re-orientation occurred only in cells where forward growth was countered by hyphal friction sufficient to generate a tip force of ∼ 8.7 μN (1.2 MPa), more than that required to penetrate host-cell membranes. These findings suggest mechanisms through which the organisation of hyphal tip growth in C. albicans facilitates the probing, penetration and invasion of host tissue.
AB - Filamentous hyphae of the human pathogen, Candida albicans, invade mucosal layers and medical silicones. In vitro, hyphal tips re-orient thigmotropically on contact with small obstacles. It is not known how surface topography is sensed but hyphae lacking the cortical marker, Rsr1/Bud1, are unresponsive. We show that, on surfaces, the morphology of hyphal tips and the position of internal polarity-protein complexes are asymmetrically skewed towards the substratum, and biased towards the softer of two surfaces. In nano-fabricated chambers, the Spitzenkörper (Spk) responded to touch by translocating across the apex towards the point of contact, where its stable maintenance correlated with contour-following growth. In the rsr1Δ mutant, the position of the Spk meandered and these responses were attenuated. Perpendicular collision caused lateral Spk oscillation within the tip until after establishment of a new growth axis, suggesting Spk position does not predict the direction of growth in C. albicans. Acute tip re-orientation occurred only in cells where forward growth was countered by hyphal friction sufficient to generate a tip force of ∼ 8.7 μN (1.2 MPa), more than that required to penetrate host-cell membranes. These findings suggest mechanisms through which the organisation of hyphal tip growth in C. albicans facilitates the probing, penetration and invasion of host tissue.
U2 - 10.1111/cmi.12369
DO - 10.1111/cmi.12369
M3 - Article
C2 - 25262778
VL - 17
SP - 342
EP - 354
JO - Cellular Microbiology
JF - Cellular Microbiology
SN - 1462-5814
IS - 3
ER -