Messenger RNA transport in the opportunistic fungal pathogen Candida albicans

Candida albicans, a common commensal fungus, can cause disease in immunocompromised hosts ranging from mild mucosal infections to severe bloodstream infections with high mortality rates. The ability of C. albicans cells to switch between a budding yeast form and an elongated hyphal form is linked to pathogenicity in animal models. Hyphal-specific proteins such as cell-surface adhesins and secreted hydrolases facilitate tissue invasion and host cell damage, but the specific mechanisms leading to asymmetric protein localization in hyphae remain poorly understood. In many eukaryotes, directional cytoplasmic transport of messenger RNAs that encode asymmetrically localized proteins allows efficient local translation at the site of protein function. Over the past two decades, detailed mechanisms for polarized mRNA transport have been elucidated in the budding yeast Saccharomyces cerevisiae and the filamentous fungus Ustilago maydis. This review highlights recent studies of RNA-binding proteins in C. albicans that have revealed intriguing similarities to and differences from known fungal mRNA transport systems. I also discuss outstanding questions that will need to be answered to reach an in-depth understanding of C. albicans mRNA transport mechanisms and the roles of asymmetric mRNA localization in polarized growth, hyphal function, and virulence of this opportunistic pathogen.