The TEA/ATTS transcription factor YlTec1p represses yeast-to-hypha transition in the dimorphic yeast Yarrowia lipolytica

Abstract

Tec1p in the budding yeast Saccharomyces cerevisiae is important for dimorphic transition. In this study, we identified a homologue of Tec1p, YlTec1p, in the distantly related dimorphic yeast Yarrowia lipolytica. YlTec1p contains an evolutionarily conserved TEA/ATTS DNA-binding domain. Expression of YlTEC1 in S. cerevisiae tec1Δ cells rescued invasive growth defect and activated a FLO11-lacZ reporter, indicating that YlTec1p is functionally related to Tec1p. However, YlTEC1 expression failed to activate a FRE-lacZ reporter, suggesting that difference exists between these two transcription factors. YlTEC1 plays a negative role in yeast-to-hypha transition in Y. lipolytica based on gene deletion and overexpression studies. We show that YlTec1p activates rather than represses gene expression in Y. lipolytica by yeast one-hybrid assay, and YlTec1p is critical for the activation of FLO11-lacZ in Y. lipolytica. In addition, YlTec1p localized to the nucleus and its nuclear localization decreased during hyphal growth. We speculate that YlTec1p may normally regulate the expression of a set of target genes that may prevent rather than promote hyphal development in Y. lipolytica. Our study also suggests that YlTEC1 may not be largely regulated by the cAMP-PKA pathway. © 2012 Federation of European Microbiological Societies. Published by Blackwell PublishingLtd. All rights reserved.