Mapping Intracellular Diffusion Distribution Using Single Quantum Dot Tracking: Compartmentalized Diffusion Defined by Endoplasmic Reticulum

Citations Over TimeTop 10% of 2014 papers

Abstract

The crowded intracellular environment influences the diffusion-mediated cellular processes, such as metabolism, signaling, and transport. The hindered diffusion of macromolecules in heterogeneous cytoplasm has been studied over years, but the detailed diffusion distribution and its origin still remain unclear. Here, we introduce a novel method to map rapidly the diffusion distribution in single cells based on single-particle tracking (SPT) of quantum dots (QDs). The diffusion map reveals the heterogeneous intracellular environment and, more importantly, an unreported compartmentalization of QD diffusions in cytoplasm. Simultaneous observations of QD motion and green fluorescent protein-tagged endoplasmic reticulum (ER) dynamics provide direct evidence that the compartmentalization results from micron-scale domains defined by ER tubules, and ER cisternae form perinuclear areas that restrict QDs to enter. The same phenomenon was observed using fluorescein isothiocyanate-dextrans, further confirming the compartmentalized diffusion. These results shed new light on the diffusive movements of macromolecules in the cell, and the mapping of intracellular diffusion distribution may be used to develop strategies for nanoparticle-based drug deliveries and therapeutics.

Related Papers

• → The endoplasmic reticulum: A dynamic and well‐connected organelle(2014)82 cited
• → Macropexophagy in Hansenula polymorpha: facts and views(2003)48 cited
• → Further Evidence for Both Functional and Structural Microcompartmentation within the Membranes of Two Associated Organelles, Mitochondrion and Endoplasmic Reticulum(1993)9 cited
• Activity of enzymes of various subcellular localisation in cytosol obtained after cell organelle precipitation at pH 5.0.(1996)
• [Compartmentalization of Ca2+ in subcellular structures of the rat liver in chemical injury of hepatocyte membranes].(1986)