The question of how cells achieve a high level of spatial organization marks a new frontier in cell biology. Most cells of the human body (e.g., epithelia, neurons) assume asymmetric shapes and develop specialized structures (e.g., cilia, axons, dendrites), which are asymmetrically positioned. Little is known about how cell shape and asymmetry arise from individual molecular interactions. My research lab is investigating the molecular mechanisms that affect spatial organization in epithelia and neurons. We focus on the cytoskeleton, a network of rigid and yet dynamic polymers that sculpt and support cell shape and provide a scaffold for the transport and positioning of the cell’s organelles and macromolecules. We are interested in understanding how cytoskeletal organization and cytoskeleton-dependent transport are spatially regulated. We have gained new insights into this problem by studying a family of GTP-binding proteins termed septins, which associate with the cytoskeleton and cell membranes. Unlike the monomeric small GTPases, septins polymerize into higher order filamentous structures that scaffold and restrict protein localization in the cytoplasm and cell membranes. We have discovered that septins demarcate spatially distinct regions of the cytoplasm, interacting with distinct subsets of microtubules and actin filaments. Importantly, we have found that septins are required for the generation of epithelial and neuronal cell asymmetry and the spatial organization of a variety of cell processes (e.g., cell division and motility) and structures (e.g., axon branches, primary cilia). We hypothesize that septins are key regulators of spatial organization and investigate the molecular mechanisms underlying the regulatory functions of septins.
Currently, we are interested in understanding:
- How septins affect the spatial organization of the microtubule cytoskeleton and microtubule motor-dependent transport of membrane cargo;
- How septins affect the spatial organization of actin stress fibers and their mechanotransducing properties that drive cell migration;
- How septins regulate the spatiotemporal dynamics of the molecular machinery of abscission, the final step in cytokinesis that separates two daughter cells.
These projects bear significance for understanding and treating neurological disorders and cancers, in which septins are abnormally expressed.
Elias Spiliotis received his Bachelor of Science from Boston College and Doctor Philosophy from The Johns Hopkins University. Subsequently, he moved to Stanford University, where he held a post-doctoral fellowship from The Jane Coffin Childs Memorial Fund for Medical Research. In the lab of cell biologist James Nelson, he focused on the regulation of the cytoskeleton and its functions by a novel family of GTP-binding proteins termed septins. Elias joined the Biology Department in the fall of 2008. He is a member of the American Society for Cell Biology and the American Association for Cancer Research; a recipient of the 2009 Drexel Career Development Award and was featured as the “Scientist to Watch” in the December 2010 issue of The Scientist magazine. Elias Spiliotis holds a joint appointment in the Department of Neurobiology and Anatomy (Drexel University College of Medicine), and serves as the Director of the Biology Cell Imaging Center. In his spare time, Elias has djed radio shows, written music reviews, and performed and recorded with an independent post-punk band.