Transcriptional Profiling of Biofilm Regulators Identified by an Overexpression Screen in <i>Saccharomyces cerevisiae</i>

Abstract

Biofilm formation by microorganisms is a major cause of recurring infections and removal of biofilms has proven to be extremely difficult given their inherent drug resistance . Understanding the biological processes that underlie biofilm formation is thus extremely important and could lead to the development of more effective drug therapies, resulting in better infection outcomes. Using the yeast <i>Saccharomyces cerevisiae</i> as a biofilm model, overexpression screens identified <i>DIG1</i>, <i>SFL1</i>, <i>HEK2</i>, <i>TOS8</i>, <i>SAN1</i>, and <i>ROF1/YHR177W</i> as regulators of biofilm formation. Subsequent RNA-seq analysis of biofilm and nonbiofilm-forming strains revealed that all of the overexpression strains, other than <i>DIG1</i> and <i>TOS8</i>, were adopting a single differential expression profile, although induced to varying degrees. <i>TOS8</i> adopted a separate profile, while the expression profile of <i>DIG1</i> reflected the common pattern seen in most of the strains, plus substantial <i>DIG1</i>-specific expression changes. We interpret the existence of the common transcriptional pattern seen across multiple, unrelated overexpression strains as reflecting a transcriptional state, that the yeast cell can access through regulatory signaling mechanisms, allowing an adaptive morphological change between biofilm-forming and nonbiofilm states.