title: Quantitative Analyses of Force-Induced Amyloid Formation in Candida albicans Als5p: Activation by Standard Laboratory Procedures.
abstract: Candida albicans adhesins have amyloid-forming sequences. In Als5p, these amyloid sequences cluster cell surface adhesins to create high avidity surface adhesion nanodomains. Such nanodomains form after force is applied to the cell surface by atomic force microscopy or laminar flow. Here we report centrifuging and resuspending S. cerevisiae cells expressing Als5p led to 1.7-fold increase in initial rate of adhesion to ligand coated beads. Furthermore, mechanical stress from vortex-mixing of Als5p cells or C. albicans cells also induced additional formation of amyloid nanodomains and consequent activation of adhesion. Vortex-mixing for 60 seconds increased the initial rate of adhesion 1.6-fold. The effects of vortex-mixing were replicated in heat-killed cells as well. Activation was accompanied by increases in thioflavin T cell surface fluorescence measured by flow cytometry or by confocal microscopy. There was no adhesion activation in cells expressing amyloid-impaired Als5pV326N or in cells incubated with inhibitory concentrations of anti-amyloid dyes. Together these results demonstrated the activation of cell surface amyloid nanodomains in yeast expressing Als adhesins, and further delineate the forces that can activate adhesion in vivo. Consequently there is quantitative support for the hypothesis that amyloid forming adhesins act as both force sensors and effectors.
authors.affiliation: Biology Department, Brooklyn College City University of New York, New York, New York, United States of America; The Graduate Center, City University of New York, New York, New York, United States of America; Haskins Laboratories and the Department of Chemistry and Physical Sciences, Pace University, New York, New York, United States of America.
authors.forename: Cho X J
authors.initials: CX
authors.lastname: Chan
authors.affiliation: Biology Department, Brooklyn College City University of New York, New York, New York, United States of America.
authors.forename: Ivor G
authors.initials: IG
authors.lastname: Joseph
authors.affiliation: Biology Department, Brooklyn College City University of New York, New York, New York, United States of America.
authors.forename: Andy
authors.initials: A
authors.lastname: Huang
authors.affiliation: Biology Department, Brooklyn College City University of New York, New York, New York, United States of America.
authors.forename: Desmond N
authors.initials: DN
authors.lastname: Jackson
authors.affiliation: Biology Department, Brooklyn College City University of New York, New York, New York, United States of America; The Graduate Center, City University of New York, New York, New York, United States of America.
authors.forename: Peter N
authors.initials: PN
authors.lastname: Lipke
mesh_terms: D000682:Amyloid / Q000235:genetics / Q000378:metabolism*; D002176:Candida albicans / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D002498:Centrifugation; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D017354:Point Mutation; D013314:Stress, Mechanical
chemical_list: C109455:ALA1 protein, Candida albicans; D000682:Amyloid; D015815:Cell Adhesion Molecules; D005656:Fungal Proteins