APSES proteins regulate morphogenesis and metabolism in Candida albicans.

Fungal APSES proteins regulate morphogenetic processes, including filamentation and differentiation. The human fungal pathogen Candida albicans contains two APSES proteins: the regulator Efg1p and its homologue Efh1p, described here. Overexpression of EFG1 or EFH1 led to similar phenotypes, including pseudohypha formation and opaque-white switching.

Adaptation of the Efg1p morphogenetic pathway in Candida albicans by negative autoregulation and PKA-dependent repression of the EFG1 gene.

The Efg1p regulator protein permits hyphal morphogenesis in the human fungal pathogen Candida albicans. We have identified the major promoter of the EFG1 gene as a direct target of Efg1p, resulting in negative autoregulation of EFG1. Enhanced activity of protein kinase A (PKA) isoforms Tpk1p and Tpk2p or exogenous overexpression of EFG1 led to Efg1p-dependent down-regulation of the endogenous EFG1 promoter.