[Regulation of cell growth and filamentation in Candida albicans by high-affinity iron permeases Ftr1 and Ftr2].

OBJECTIVE

To determine the function of high-affinity iron permeases, Ftr1 and Ftr2, we studied cell growth and filamentation ability of the ftr1/ftr1, ftr2/ftr2, and ftr1/ftr1 ftr2/ftr2 mutants under different culture conditions.

METHODS

Cells of the wild type and mutants were cultured on different solid media at different temperatures. Cell growth and filamentation were observed.

RESULTS

Deletion of either one of the FTR genes had no effect on the growth under all conditions tested. Deletion of both FTR1 and FTR2 led to obvious growth defect on Spider media, although addition of FeCl3 restored their growth. The double mutant also grew much more slowly on nutrients-limited synthetic media such as Lee's glucose and Lee's GlcNAc (N-acetylglucosamine). Moreover, deletion of FTR1 enhanced filamentation, whereas deletion of FTR2 weakened this ability. Deletion of both FTR1 and FTR2 recovered the ability of filamentation.

CONCLUSION

Ftr1 and Ftr2 are very important for C. albicans growth under iron-limited condition and may participate in the utilization of some carbon sources including GlcNAc, ethnol, and glycerol. Ftr1 plays a negative, whereas Ftr2 plays a positive role in the regulation of filamentation in C. albicans.