Monitoring Phosphatidic Acid Signaling in Breast Cancer Cells Using Genetically Encoded Biosensors.

Phospholipids are important signaling molecules that regulate cell proliferation, death, migration, and metabolism. Many phospholipid signaling cascades are altered in breast cancer. To understand the functions of phospholipid signaling molecules, genetically encoded phospholipid biosensors have been developed to monitor their spatiotemporal dynamics. Compared to other phospholipids, much less is known about the subcellular production and cellular functions of phosphatidic acid (PA), partially due to the lack of a specific and sensitive PA biosensor in the past. This chapter describes the use of a newly developed PA biosensor, PASS, in two applications: regular fluorescent microscopy and fluorescence lifetime imaging microscopy-Förster/fluorescence resonance energy transfer (FLIM-FRET). These protocols can be also used with other phospholipid biosensors.