Defining the Role of Hem25 in Mitochondrial Function: Implications for Congenital Sideroblastic Anemia

Abstract

Congenital sideroblastic anemia (CSA) is a hematological disease caused by mutations in genes that result in a defect in heme/hemoglobin biosynthesis. Mutations in SLC25A38 cause CSA. I determined that SLC25A38, and its budding yeast Saccharomyces cerevisiae homologue Hem25, are mitochondrial glycine transporters with the imported glycine used in the first enzymatic step in heme synthesis. I also performed genetic interaction analyses and determined that loss of function of a small subset of the SLC25 members found in yeast results in decreased fitness for cells lacking Hem25 function. The genetic interaction between FLX1, encoding a flavin transporter, and HEM25 was studied in further detail. My results showed that the abundance in electron transport chain subunits was decreased in flx1 hem25 cells. My genetic screen may help discover new pathways and processes that affect cell fitness when Hem25 function/heme synthesis is deficient.