Responses to phosphate deprivation in yeast cells

Inorganic phosphate is an essential nutrient
because it is required for the biosynthesis of nucleotides,
phospholipids and metabolites in energy metabolism. During
phosphate starvation, phosphatases play a major role
in phosphate acquisition by hydrolyzing phosphorylated
macromolecules. In Saccharomyces cerevisiae, PHM8
(YER037W), a lysophosphatidic acid phosphatase, plays
an important role in phosphate acquisition by hydrolyzing
lysophosphatidic acid and nucleotide monophosphate that
results in accumulation of triacylglycerol and nucleotides
under phosphate limiting conditions. Under phosphate limiting
conditions, it is transcriptionally regulated by Pho4p,
a phosphate-responsive transcription factor. In this review,
we focus on triacylglycerol metabolism in transcription
factors deletion mutants involved in phosphate metabolism
and propose a link between phosphate and triacylglycerol
metabolism. Deletion of these transcription factors results
in an increase in triacylglycerol level. Based on these
observations, we suggest that PHM8 is responsible for the
increase in triacylglycerol in phosphate metabolising gene
deletion mutants.