10 March 2023
Elena Koslover
Department of Physics
UC San Diego
Eukaryotic cells face the challenging task of delivering and distributing a variety of components through a morphologically complex environment. In this talk, we will explore how intracellular transport is modulated by the geometry of cellular structures, focusing specifically on transport within network architectures. We will first discuss diffusive transport of proteins and ions in the tubular networks of organelles such as the endoplasmic reticulum, where highly looped architectures are shown to support more rapid encounter kinetics. Calcium transport within the ER will also be considered, demonstrating that local calcium release is enhanced by mobile buffer proteins of moderate binding strength, confined within a well-connected lattice network structure. We will then turn to active transport systems in cellular networks, focusing on the delivery of mitochondria in dendritic trees. The mitochondrial distribution is shown to be determined by scaling laws that govern dendritic branch width. Intriguingly, we find that the dendritic arbors of HS neurons in the Drosophila visual system obey a specific set of geometric laws that enables an equitable distribution of organelles between subtrees. Overall, our physical models of intracellular transport systems highlight the importance of network morphology in determining particle distribution and kinetics within the cell.