Macropinocytosis and phagocytosis are the processes by which eukaryotic cells use their plasma membrane to engulf liquid or a large particle and give rise to an internal compartment called the macropinosomes or phagosome, respectively. Dictyostelium discoideum provides a powerful system to understand the molecular mechanism of these two fundamental cellular processes that impact human health and disease. Recent developments in fluorescence microscopy allow direct visualization of intracellular signaling events with high temporal and spatial resolution. Here, we describe methods to visualize temporospatial activation or localization of key signaling components that are crucial for macropinocytosis and phagocytosis using confocal fluorescence microscopy.
Keywords: Active Ras-binding domain of Raf1 (RBD); Dictyostelium discoideum; Fluorescence microscopy; Macropinocytosis; Phagocytosis; Phosphatidylinositol 3,4,5-trisphosphate (PIP3); Phosphatidylinositol 4,5-bisphosphate (PIP2); Phosphoinositide 3-kinases (PI3K); Pleckstrin homology domain (PH domain); Ras.