Transcriptional control of dimorphism in Candida albicans

Abstract

Candida albicans uses a network of multiple signaling pathways to control the yeast-->hypha transition. These include a mitogen-activated protein kinase pathway through Cph1, the cAMP-dependent protein kinase pathway via Efg1, a pH-responsive pathway through Rim101, the Tup1-mediated repression through Rfg1 and Nrg1, and pathways represented by transcription factors Cph2, Tec1 and Czf1. These pathways control the transcription of a common set of hypha-specific genes, many of which encode known virulence factors. The link between the signaling pathways and hyphal elongation is currently unknown, but there is evidence to suggest that Cdc42 likely plays a key role in hyphal morphogenesis. Unlike pseudohyphal growth in Saccharomyces cerevisiae, hyphal elongation is regulated independently of the cell cycle. Cellular differences between pseudohyphae and hyphae are further revealed by septin localization.