high-throughput-measurement-dictyostelium-discoideum-macropinocytosis

High-throughput Measurement of <em>Dictyostelium discoideum</em> Macropinocytosis by Flow Cytometry

Large-scale non-specific fluid uptake by macropinocytosis is important for the proliferation of certain cancer cells, antigen sampling, host cell invasion ...

MRC-Laboratory of Molecular Biology, Cambridge, UK

Macropinocytosis is a conserved endocytic process used by  amoebae for feeding on liquid medium. To further  as a model for macropinocytosis, we developed a high-throughput flow cytometry assay to measure macropinocytosis, and used it to identify inhibitors and investigate the physiological regulation of macropinocytosis.  has two feeding states: phagocytic and macropinocytic. When cells are switched from phagocytic growth on bacteria to liquid media, the rate of macropinocytosis slowly increases, due to increased size and frequency of macropinosomes. Upregulation is triggered by a minimal medium containing three amino acids plus glucose and likely depends on macropinocytosis itself. The presence of bacteria suppresses macropinocytosis while their product, folate, partially suppresses upregulation of macropinocytosis. Starvation, which initiates development, does not of itself suppress macropinocytosis: this can continue in isolated cells, but is shut down by a conditioned-medium factor or activation of PKA signalling. Thus macropinocytosis is a facultative ability of  cells, regulated by environmental conditions that are identified here.This article has an associated First Person interview with the first author of the paper.

Thomas Williams

MRC-Laboratory of Molecular Biology, Cambridge, UK

High-throughput Measurement of Dictyostelium discoideum Macropinocytosis by Flow Cytometry