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BIO SEMINAR:Understanding organelle structure and function...

Speaker:Bala Anı Akpınar

Title: Understanding organelle structure and function: insights from peroxisomes and mitochondria

Date/Time:March 30, 2023 12:40PM


Abstract:Peroxisomes and mitochondria are organelles with crucial roles to the proper  functioning of the cell. In addition to distinct functions, these organelles are also  interlinked in fatty acid and ROS metabolism. Peroxisomes are single membrane-bound  organelles that lack their own genomes. Thus, all proteins that are required for  peroxisome assembly and function must be imported from the cytosol. Matrix proteins, required for peroxisome biogenesis, are generally recognized and imported through a  peroxisomal targeting signal (PTS). We studied peroxisome structure and function  experimentally using an APEX2-ePTS1 construct that allows proximity labeling in living  cells and aids in enhanced contrast in fixed cells. Our preliminary data suggest the  capture of new, potentially essential, unknown peroxisomal biogenesis factors. Our  fusion construct also enables a better understanding of peroxisomal ultrastructure and  interorganellar contact sites by improved contrast in electron microscopy. Mitochondria, on the other hand, are double membrane-bound organelles with their own  genomes, which are highly compact and remarkably conserved across mammalians.  Mutations in the mitochondrial genome (mtDNA) across several conserved residues  often lead to severe mitochondrial diseases. Yet, the prediction of clinical outcomes of  mtDNA variations is highly challenging due to heteroplasmy, genetic interactions among  alleles and environmental effects. We devised a new computational approach,  combined with machine learning, to assess the pathogenicity of mtDNA variants. Our  work on thousands of human mtDNA variants suggest that a substantial fraction of  variants, which have not been linked to mitochondrial diseases yet, are likely  deleterious.

Bio:Dr. Akpınar received her PhD in 2015 in Sabancı University on plant genomics. She  continued to work on plant genomics, expanding her work into wild wheat germplasm  and insect resistance during her early postdoctoral career. She later moved to the  University of Helsinki, as a postdoctoral fellow in Dunn lab, where she worked on  organelle structure and function. Since 2020, she is working remotely as a senior  scientist at Montana BioAgriculture Inc., leading the omics team. In addition to her  current work in plant genomics with a focus on non-coding elements, her research  interests, inspired by her work at the University of Helsinki, also include chloroplasts  and mitochondria, and how these organelles modulate the energy metabolism in plant