ATG15 encodes a phospholipase and is transcriptionally regulated by YAP1 in Saccharomyces cerevisiae.

Phospholipases play a vital role in maintaining membrane phospholipids. In this
study, we found that deletion of the three major phospholipases B in Saccharomyces
cerevisiae did not affect the hydrolysis of phospholipids, thus suggesting
the presence of other, as yet unidentified, phospholipases. Indeed, in silico analysis
of the S. cerevisiae genome identified 13 proteins that contain a conserved, putative
serine hydrolase motif. In addition, expression profiling revealed that ATG15
(Autophagy 15) was highly expressed in the phospholipase B triple mutant. ATG15
encodes a phospholipase that preferentially hydrolyzes phosphatidylserine. Our
analysis of the ATG15 promoter identified binding sites for Yap1p. In vivo and
in vitro results showed that Yap1p positively regulates ATG15 expression. Collectively,
we demonstrate that Atg15p is a phosphatidylserine lipase and that Yap1p
activates the expression of ATG15 during autophagy.