bioRxiv Science⌕ Search

Biology subjects

Rogers, S. W.

Publications and source records attributed to Rogers, S. W..

2 recordsLinked to original sources

Fmp30 is a phosphatidylinositol hydrolase that regulates CoQ biosynthesis

Coenzyme Q (CoQ, ubiquinone) is a redox-active isoprene lipid that supports fundamental enzymatic and antioxidant roles in mitochondria and beyond. Despite CoQs importance in organismal health and disease, the mechanisms that regulate its biosynthetic pathway remain elusive. Motivated by this, we mined S. cerevisiae multiomics datasets for genes whose disruptions alter CoQ levels and discovered the gene FMP30 as an unexpected negative regulator of CoQ biosynthesis. Loss of FMP30 results in elevated complex Q protein abundance, increased number and intensity of CoQ domains, and ultimately enhanced CoQ biosynthetic flux. We demonstrate that Fmp30, a member of the metallo-{beta}-lactamase super family, displays phospholipase type D activity toward phosphatidylinositol and phosphoinositides, and that its deletion causes marked elevation of these lipid species in purified mitochondria. Collectively, our work nominates Fmp30 as a novel regulator linking mitochondrial phospholipid metabolism to CoQ biosynthesis.

biochemistry↗

Hem25p is a mitochondrial IPP transporter

Coenzyme Q (CoQ, ubiquinone) is an essential cellular cofactor comprised of a redox-active quinone head group and a long hydrophobic polyisoprene tail. How mitochondria access cytosolic isoprenoids for CoQ biosynthesis is a longstanding mystery. Here, via a combination of genetic screening, metabolic tracing, and targeted uptake assays, we reveal that Hem25p--a mitochondrial glycine transporter required for heme biosynthesis--doubles as an isopentenyl pyrophosphate (IPP) transporter in Saccharomyces cerevisiae. Mitochondria lacking Hem25p fail to efficiently incorporate IPP into early CoQ precursors, leading to loss of CoQ and turnover of CoQ biosynthetic proteins. Expression of Hem25p in Escherichia coli enables robust IPP uptake demonstrating that Hem25p is sufficient for IPP transport. Collectively, our work reveals that Hem25p drives the bulk of mitochondrial isoprenoid transport for CoQ biosynthesis in yeast.

biochemistry↗