Overexpression approaches to advance understanding of Candida albicans

Abstract

Candida albicans is an opportunistic fungal pathogen that is responsible for infections linked to high mortality. Loss-of-function approaches, taking advantage of gene knockouts or inducible down-regulation, have been successfully used in this species in order to understand gene function. However, overexpression of a gene provides an alternative, powerful tool to elucidate gene function and identify novel phenotypes. Notably, overexpression can identify pathway components that might remain undetected using loss-of-function approaches. Several repressible or inducible promoters have been developed which allow to shut off or turn on the expression of a gene in C. albicans upon growth in the presence of a repressor or inducer. In this review, we summarize recent overexpression approaches used to study different aspects of C. albicans biology, including morphogenesis, biofilm formation, drug tolerance, and commensalism.

FIGURE 1

Tools that facilitate high‐throughput overexpression screens to understand the biology of Candida albicans. (a) A collection of 49 Gateway™‐adapted destination vectors for constitutive or conditional overexpression of untagged or tagged ORFs in C. albicans. (b) 83% of the C. albicans ORFeome has been cloned in the Gateway™ vector pDONR207 allowing subsequent transfer of the cloned ORFs to Gateway™‐adapted destination vectors

FIGURE 2

Schematic of gene overexpression studies affecting Candida albicans phenotypic transitions. Novel genes identified with overexpression studies during yeast‐filament, white–opaque, and yeast–GUT phenotypic transitions, or planktonic to biofilm formation are shown here