Inorganic polyphosphate in methylotrophic yeasts.

Inorganic polyphosphate (polyP) is a significant regulatory and metabolic compound in yeast cells. We compared polyP content and localization, polyphosphatase activities, and transcriptional profile of polyP-related genes in industrially important methylotrophic yeasts, Hansenula polymorpha and Pichia pastoris. The increased need for phosphate, the decrease of long-chain polyP level, the accumulation of short-chain polyP, and enhanced endopolyphosphatase activity in the crude membrane fraction were observed in methanol-grown cells compared with glucose-grown cells of both species. Transcriptome analysis revealed notable differences in the expression patterns of key genes encoding proteins related to polyP metabolism. In methanol-grown cells, the genes encoding endopolyphosphatases and phosphate transporters were upregulated. The changes in polyP metabolism are probably related to the peculiarities of bioenergetics of methanol-grown cells.