Fig4 confers tolerance to rapamycin in a Ste20-dependent manner independent of the Vac14 scaffold.

A preprint abstract from biorxiv.org discusses the role of the lipid phosphatase Fig4 in modulating the production and turnover of the signaling lipid PI3,5P2. Mutations in Fig4 are associated with neurological diseases, and disruption of the Fab1-Vac14-Fig4 complex is thought to contribute to pathology. The study shows that expression of Fig4 disease-related mutants confers tolerance to the drug rapamycin, independent of the Fab1-Vac14-Fig4 complex. This altered stress response is mediated through binding interactions with unknown proteins, and the p21-activated kinase Ste20 is specifically required for this function. The research has not yet undergone peer review. [Extracted from the article]