REGULATION OF RAS-INDUCED HYPHAL FORMATION BY HISTONE ACETYLASE GCN5 IN CANDIDA ALBICANSAbstract
Candida albicans is the leading cause of superficial and systemic fungal infections in human beings and is very common in people with a weakened immune system. It can grow either as budding yeast, a pseudohyphae form, or in a true hyphal form, and the ability to switch between these three forms is important for its pathogenicity. To date, an in-depth study on the relationship between histone modification and hyphal formation is limited, and our study has therefore aimed at adding further information regarding this relationship. In our study, we have found that by disrupting the gene GCN5that codes for a histone acetylating protein Gcn5, there was indeed a defect in the hyphal formation confirming the previous report made by Chang et al., (2015). We also found that the defect in the hyphal formation was probably due to regulation of hyphal inducing signaling protein Ras1 by Gcn5 leading to its reduced expression as well as its downstream target hyphal transcription factors Efg1 and Cph1 in the homozygous mutant. The reduced expression of Ras1 is probably caused by the reduced binding of RNA pol II onto the promoter of RAS1.