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