Abstract

The intracellular environment contains a variety of complex morphologies that can substantially affect the transport, distribution, and kinetics of particles within the cell. In this talk, we will focus on organelle structures that form interconnected networks of tubules—specifically on mitochondrial and endoplasmic reticulum (ER) networks. The ER plays a crucial role in several cellular processes, including protein quality control and calcium homeostasis, which require the transport of proteins and ligands through the tubular network. Using a combination of analytic results and numerical simulations we explore how network morphology governs encounter and target-search rates for diffusing particles confined in the network. We quantify the transport of membrane and luminal proteins from the measured spatiotemporal evolution of photoactivated protein densities, provided by collaborating groups. Finally, we identify the role of transport and network architecture in local release and refilling of ER calcium storage, combining buffered kinetics with diffusion through a network. Overall, our exploration of the interplay between transport dynamics, organelle morphology, and reaction kinetics helps elucidate the structure-function relationships of key cellular components such as the endoplasmic reticulum.