Snf1/AMPK protein kinase modulates cell wall integrity in the human pathogenic yeast cryptococcus neoformans.

OBJECTIVE

The Snf1/AMPK family of protein kinases is highly conserved among eukaryotes. Our previous study showed that Cryptococcus neoformans SNF1 played critical roles in the production of virulence factors and virulence itself. In this paper, we report a novel function of SNF1 in cell wall integrity.

METHODS

We used Calcofluor white staining epifluorescence microscopy to evaluate the cell wall integrity and cell segregation; tap water with constant flow rate and pressure to wash yeast colonies to evaluate cell-to-agar adhesion capability; growth on Sodium dodecyl sulfate (SDS), Congo red and Fluorescent Brightener 28-containing agar to examine cell wall integrity.

RESULTS

The disruption mutant of SNF1 was sensitive to SDS and Congo red, suggesting impairments in the cell wall. The mutant cells showed abnormal separation, defects in adhesion to agar surface, and growth defects at high temperature which could be suppressed by osmotic stabilization.

CONCLUSION

C. neoformans SNF1 was essential for cell wall integrity that was likely responsible for normal adhesion of the cells to agar and resistance to heat.