We performed our deletion pool experiment under starvation conditions (no external fermentable carbon sources or nitrogen sources added to the media). In this condition autophagy-related genes become essential. In rich media, however, these genes are not essential and would therefore not be observed in a deletion mutant screen. Could this be a possible explanation for the observed differences between your screens and ours?

At this point we don't know the precise underlying mechanism by which tripelennamine interferes with autophagy, nor do we know whether tripelennamine prefers to reside within certain types of membranes (for example PE-enriched membranes).

One challenge we encountered while writing the paper was to reconcile your observation (published in Rainey et al. and more recently in Chen et al.) that sertraline-treated yeast cells show an elevated number of undigested autophagosomes (presumably due to a stimulation in autophagic activities) and our claim that tripelennamine inhibits these processes. Of course both drugs may not act through the same molecular MOA. However, if we assume they did: do they diminish or increase autophagy?

You may have seen that there is a paper on the problem of measuring flux through the autophagy pathway published in the journal 'Autophagy' in April of this year (PMID: 22966490). We tried to think of ways to prove one or the other with a more direct autophagy assay, but eventually decided to publish the work as it was.