Identification of Nile red as a fluorescent substrate of the Candida albicans ATP-binding cassette transporters Cdr1p and Cdr2p and the major facilitator superfamily transporter Mdr1p.
Clinically relevant azole resistance in the fungal pathogen Candida albicans is most often associated with the increased expression of plasma membrane efflux pumps, specifically the ATP-binding cassette (ABC) transporters CaCdr1p and CaCdr2p and the major facilitator superfamily (MFS) transporter CaMdr1p. Development of potent pump inhibitors that chemosensitize cells to azoles is a promising approach to overcome antifungal resistance. Here we identify Nile red as a new fluorescent substrate for CaCdr1p, CaCdr2p, and CaMdr1p. Nile red was effluxed efficiently from Saccharomyces cerevisiae cells heterologously expressing these transporters. Enniatin selectively inhibited the efflux of Nile red from S. cerevisiae cells expressing CaCdr1p or CaMdr1p but not from cells expressing CaCdr2p. This indicates that Nile red can be used for the identification of inhibitors specific for particular transporters mediating antifungal resistance in pathogenic yeast.
Ivnitski-Steele
Irena
I
New Mexico Center for Molecular Discovery, University of New Mexico, Albuquerque, NM 87131, USA. iivnitski@salud.unm.edu
Holmes
Ann R
AR
Lamping
Erwin
E
Monk
Brian C
BC
Cannon
Richard D
RD
Sklar
Larry A
LA
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D001692:Biological Transport / Q000187:drug effects; D002176:Candida albicans; D047630:Depsipeptides / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000378:metabolism*; D005656:Fungal Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010078:Oxazines / Q000032:analysis / Q000378:metabolism*; D012235:Rhodamines / Q000378:metabolism
D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D047630:Depsipeptides; D005456:Fluorescent Dyes; D005656:Fungal Proteins; D010078:Oxazines; D012235:Rhodamines; C100264:enniatins; C026188:rhodamine 6G; C044808:nile red