The fission yeast GATA factor, Gaf1, modulates sexual development via direct down-regulation of ste11+ expression in response to nitrogen starvation

• Published in: PloS one Vol. 7; no. 8; p. e42409
• Main Authors: Kim, Lila, Hoe, Kwang-Lae, Yu, Yeong Man, Yeon, Ji-Hyun, Maeng, Pil Jae
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 10-08-2012; Public Library of Science (PLoS)
• Subjects: Baking yeast; Base Sequence; Binding Sites - genetics; Biology; Cell cycle; Cloning; DNA microarrays; Down-Regulation; Electrophoretic mobility; Epistasis; Epistasis, Genetic; G1 Phase Cell Cycle Checkpoints - genetics; GATA Transcription Factors - metabolism; Gene Deletion; Gene expression; Gene Expression Profiling; Gene Expression Regulation, Fungal; Gene regulation; Genes; Genetic engineering; Glucose; Kinases; Meiosis; Molecular biology; Mutation; Nitrogen; Nitrogen - metabolism; Nucleotide Motifs; Phenotypes; Pheromones; Pheromones - genetics; Promoter Regions, Genetic; Proteins; Saccharomyces cerevisiae; Schizosaccharomyces - genetics; Schizosaccharomyces - metabolism; Schizosaccharomyces - physiology; Schizosaccharomyces pombe; Schizosaccharomyces pombe Proteins - genetics; Schizosaccharomyces pombe Proteins - metabolism; Signal transduction; Signaling; Spores, Fungal - genetics; Sporulation; Trans-Activators - genetics; Trans-Activators - metabolism; Transcription factors; Transcription Factors - genetics; Vitamin B; Yeast; Zinc; Zinc finger proteins
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0042409

Gaf1 is the first GATA family zinc-finger transcription factor identified in Schizosaccharomyces pombe. Here, we report that Gaf1 functions as a negatively acting transcription factor of ste11(+), delaying the entrance of cells exposed to transient nitrogen starvation into the meiotic cycle. gaf1Δ strains exhibited accelerated G(1)-arrest upon nitrogen starvation. Moreover, gaf1Δ mutation caused increased mating and sporulation frequency under both nitrogen-starved and unstarved conditions, while overexpression of gaf1(+) led to a significant impairment of sporulation. By microarray analysis, we found that approximately 63% (116 genes) of the 183 genes up-regulated in unstarved gaf1Δ cells were nitrogen starvation-responsive genes, and furthermore that 25 genes among the genes up-regulated by gaf1Δ mutation are Ste11 targets (e.g., gpa1(+), ste4(+), spk1(+), ste11(+), and mei2(+)). The phenotype caused by gaf1Δ mutation was masked by ste11Δ mutation, indicating that ste11(+) is epistatic to gaf1(+) with respect to sporulation efficiency, and accordingly that gaf1(+) functions upstream of ste11(+) in the signaling pathway governing sexual development. gaf1Δ strains showed accelerated ste11(+) expression under nitrogen starvation and increased ste11(+) expression even under normal conditions. Electrophoretic mobility shift assay analysis demonstrated that Gaf1 specifically binds to the canonical GATA motif (5'-HGATAR-3') spanning from -371 to -366 in ste11(+) promoter. Consequently, Gaf1 provides the prime example for negative regulation of ste11(+) transcription through direct binding to a cis-acting motif of its promoter.