Metabolic and developmental effects resulting from deletion of the citA gene encoding citrate synthase in Aspergillus nidulans

Abstract

Citrate synthase is a central activity in carbon metabolism. It is required for the tricarboxylic acid (TCA) cycle, respiration, and the glyoxylate cycle. In Saccharomyces cerevisiae and Arabidopsis thaliana, there are mitochondrial and peroxisomal isoforms encoded by separate genes, while in Aspergillus nidulans, a single gene, citA, encodes a protein with predicted mitochondrial and peroxisomal targeting sequences (PTS). Deletion of citA results in poor growth on glucose but not on derepressing carbon sources, including those requiring the glyoxylate cycle. Growth on glucose is restored by a mutation in the creA carbon catabolite repressor gene. Methylcitrate synthase, required for propion..