Description
Title: "Exploring Plasmodium Parasite Cell Division Processes through Expansion Microscopy Visualization"
Speaker: 
Sabrina Absalon, PhD
Associate Professor,
Department of Pharmacology and Toxicology
Indiana University School of Medicine
Indianapolis, Indiana
Abstract:
The centrosome, a prominent microtubule organizing center (MTOC) in animal cells, plays a pivotal role in orchestrating microtubule organization during cell division, ensuring proper chromosome segregation and genetic material distribution to daughter cells. Additionally, non- centrosomal MTOCs (ncMTOCs) are prevalent in non-dividing animal cells, crucial for microtubule organization involved in cell polarity, motility, and intracellular transport. Unicellular eukaryotic pathogens within the Apicomplexa phylum, including Plasmodium falciparum, Toxoplasma gondii, and Cryptosporidium parvum, utilize distinct ncMTOCs for their unique cell division strategies. Despite their medical significance, fundamental understanding of the biology of these pathogens, especially pertaining to cell division processes and the role of ncMTOCs, remains limited. Using Ultrastructure Expansion Microscopy (U-ExM) coupled with fluorescence microscopy, our recent study investigated the biogenesis and protein distribution of 14 structures within the parasite during erythrocytic asexual replication. An intriguing finding was the anchoring of the nucleus to the parasite plasma membrane by the cytosolic extension of the ncMTOC or centriolar plaque (CP) during replication. This interaction ceases during cell division, where the CP associates with mitochondria instead. The space between the parasite plasma membrane and CP contains crucial structures and organelles, including the Golgi and other apical structures essential for cytokinesis and invasion. While ncMTOCs play a role in establishing apical-basal polarity in differentiated animal cells, their role in this aspect within Plasmodium remains elusive. Understanding Plasmodium ncMTOCs is essential for advancing parasite biology and identifying drug targets. Our lab focuses on unraveling the molecular mechanisms underlying ncMTOC formation and function during P. falciparum asexual replication, recognizing their potential as drug targets.
Bio:
Dr. Sabrina Absalon received her B.S. in Biochemistry and Ph.D. in cellular and molecular biology from the University Pierre and Marie Curie in Paris, France. Her graduate work in Dr. Philippe Bastin's Lab at Pasteur Institute Paris focused on studying flagellum assembly and function in the protozoan parasite Trypanosoma brucei. She then moved to Boston for her first postdoctoral training in Dr. Anna Krichevsky's Lab at the Harvard Institute of Medicine to determine the contribution of microRNAs to Alzheimer's disease progression.
In 2011, she went back to parasitology and joined a research group led by Dr. Jeffrey Dvorin at Boston Children's Hospital, where she studied the molecular pathogenesis of malaria infection. She joined the Department of Pharmacology and Toxicology at the Indiana University School of Medicine in October 2019, where she is currently an Assistant professor.
Date: Monday, November 20, 2023
Time: 12 pm
Location: Hill Pavilion Room 132 and available virtually Via Zoom
Questions? Please contact Michael Black if you have questions.