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 - This article is protected by copyright. All rights reserved.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited
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 -