Fig. 7.

Model for Ubxd8-mediated cellular responses to exogenous unsaturated FAs. (A) Cells incubated in the absence of exogenous unsaturated FAs. In these cells Ubxd8 promotes synthesis of FAs and inhibits incorporation of FAs into TGs. These two regulatory actions allow cells to maintain enough FAs for their survival. (B) Cells incubated in the presence of exogenous unsaturated fatty acids (uFAs). In these cells excessive unsaturated FAs inactivate Ubxd8 by promoting its polymerization. In the absence of active Ubxd8, synthesis of endogenous FAs is inhibited and excessive FAs are channeled into TGs. These two regulatory actions prevent toxic overaccumulation of FAs.