University of Pittsburgh

The broad objective of my current research is to develop a multiscale imaging pipeline for determining complex molecular structures that explicitly closes the gaps between distinct imaging modalities. Structural determination of 3D biological molecules and complexes in cellular context, is crucial for understanding, exploiting, and even engineering biological functions. These 3D structures visualize the mechanisms underlying health and disease and guide hypotheses for strategies to prevent or cure disease. Recent advances in structural biology, computer science, and single-particle cryogenic electron microscopy (cryo-EM) have revolutionized our ability to solve near-atomic structures of macromolecules in solution. The next major challenge is to link our understanding of the structures of these molecules/complexes to specific molecular contexts in health and disease; this challenge is complicated by the powerful yet distinct imaging modalities being used around the world. To meet this challenge, I will integrate complementary cryo-EM imaging tools including cryogenic electron tomography (cryo-ET), cryo-focused ion beam and scanning electron microscopy (cryoFIB-SEM) to establish a scale-bridging 3D imaging pipeline. I will employ machine-learning algorithms for imaging analysis, including cellular annotation, and integrate these algorithms with subvolume alignment and reconstruction to derive structures from cellular machinery in context all the way down to the level of single molecules. My lab is interested in 1) Determine the assembly process of the flagellar membrane adhesion protein in the extracellular parasite Trypanosoma brucei, a causative agent for the sleeping sickness in humans and Nagana in Africa, to understand the flagellum driven motility and pathogenesis; 2) Determine the molecular structure of the invasion machinery in the intracellular apicomplexan parasites including several of the most prevalent and important human pathogens, causing malaria (Plasmodium) to understand the cytoskeleton-based invasion and proliferation mechanism.