Yeast phospholipase D, Spo14, is not required for macroautophagy

Autophagy-related gene (Atg) proteins are key players in autophagy. Some proteins that function in vesicle trafficking and lipid metabolism are also involved in autophagy. The SPO14 in yeast, which encodes phospholipase D (PLD), is involved in membrane trafficking and plays a vital role in sporulation during meiosis. Crosstalk has been identified between autophagy and sporulation. Although the PLD is required for macroautophagy in mammals, its role in yeast macroautophagy remains unclear. We observed that Spo14 is not required for macroautophagy in yeast and that it is dispensable for Atg8 lipidation, which plays an important role in phagophore extension. Our results also revealed that green fluorescent protein (GFP)-Atg8 degradation is not completely blocked in atg1 Δ/ atg1 Δ cells under sporulation condition. Therefore, Spo14 is not required for macroautophagy in yeast. Take away Yeast phospholipase D, Spo14, is dispensable for macroautophagy in haploid and diploid cells. The essential role of Spo14 in sporulation in diploid yeast cells is not associated with macroautophagy. The unique distribution of fluorescent proteins in WT/WT tetrads in a sporulation medium is not autofluorescence.