Jon Lane’s lab has published a new paper describing new regulators of autophagy during starvation and mitophagy. The authors screened 61 genes involved ER and mitochondrial function by silencing them in RP1 cells and measuring autophagic activity after starvation with two assays: the mCherry-GFP-LC3 assay, to measure autophagosome formation and flux, and the GFP-ATG5 assay to independently measure autophagosome formation and maturation. These assays identified the σ-receptor 1 (SIGMAR1) gene as a hit, as silencing its expression led to accumulation of GFP-ATG5 puncta. The same genes were also assayed in a mitophagy assay by measuring the amount of mitochondria after CCCP (which induces mitochondiral damage) in YFP-PARKIN expresssing RP1 cells. In this mitophagy screen PE methyltransferase (PEMT) was shown to block mitophagy leading to the accumulation of mitochondria after CCCP treatment.
Access the article here: Targeted siRNA Screens Identify ER-to-Mitochondrial Calcium Exchange in Autophagy and Mitophagy Responses in RPE1 Cells. Int J Mol Sci. 2015 Jun 11;16(6):13356-80.