Lipid Research Division Seminar Series

Mitochondrial phosphatidylinositol abundance regulates coenzyme Q biosynthesis
Zak Baker, Washington University in St. Louis

Mitochondrial lipidomes are diverse, however, functional roles for multiple lipid classes within the organelle are unknown. One such lipid class is phosphatidylinositol (PI). We have characterized the mitochondrial protein Fmp30p as a PI phospholipase-D enzyme that regulates PI abundance within yeast mitochondria. Interestingly, we found that altering mitochondrial PI levels, through changes in Fmp30p expression, impacts the biosynthesis of the redox-active lipid cofactor coenzyme Q (CoQ). My webinar will cover our efforts to biochemically characterize Fmp30p and uncover how it regulates CoQ metabolism through PI. This work will have great interest from the lipid metabolism and mitochondrial biology fields.

Alterations in lipid saturation trigger remodeling of the outer mitochondrial membrane
Sara Wong, University of Utah

Lipid saturation is a key determinant of membrane function and organelle health, with changes in saturation triggering adaptive quality control mechanisms to maintain membrane integrity. Among cellular membranes, the outer mitochondrial membrane (OMM) is an important interface for many cellular functions, but how lipid saturation impacts OMM function remains unclear. Here, we show that increased intracellular unsaturated fatty acids (UFAs) remodel the OMM by promoting the formation of mitochondrial-derived compartments (MDC). Our findings suggest that alterations in phospholipid saturation may destabilize OMM protein complexes and trigger an adaptive response to sequester excess membrane proteins through MDC formation.