Trypanosoma cruzi Proline Transport Presents a Cell Density-dependent Regulation

SAYE M; MIRANDA MR; REIGADA C; PEREIRA CA

JOURNAL OF EUKARYOTIC MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2016

1066-5234

Trypanosoma cruzi, the etiological agent of Chagas disease, uses proline as itsmain carbon source, essential for parasite growth and stage differentiation inepimastigotes and amastigotes. Since proline is mainly obtained from extracellular medium by transport proteins, in this work we studied the regulation of the T. cruzi proline transporter TcAAAP069. Proline uptake and intracellularconcentration presented oscillations during epimastigote growth phases,increasing during the early exponential phase (322 pmol/min) and decreasing to undetectable levels during the late exponential phase. Transporter expression rate correlated with proline uptake, and its subcellular localization alternated from both, the plasma membrane and close to the flagellar pocket,when the transport is higher, to only the flagellar pocket region, when thetransport decreased until proline uptake and TcAAAP069 protein became undetectableat the end of the growth curve. Interestingly, when parasites weretreated with conditioned medium or were concentrated to artificially increasethe culture density, the proline transport was completely abolished resemblingthe effects observed in late exponential phase. These data highlight for thefirst time the existence of a density-associated regulation of relevant physiologicalprocesses such as proline metabolism.