Aggregation Induced Emission Fluorogens Light Cells via Microtubules: Accessing the Mechanisms of Intracellular Trafficking of Ionic Substances.

Understanding the enrichment and intracellular trafficking of substances is centrally important to the biological systems. Here, employing an amphiphilic molecule (denoted by TPE-11) bearing tetraphenylethene moiety, known for aggregation induced emission property, we demonstrated its localization shifting in Hela cells after prolonged incubation. Through a set of delicately designed experiments, we found that one type of cytoskeleton, i.e., microtubule, is responsible for the intracellular transportation regardless of the sources of fluorogens, via endocytosis pathways or not. As the polymerization of microtubules was blocked, the TPE-11 fluorogens were hindered to move to the inner cytoplasm, but scattered in the cells. On the contrary, blocking the polymerization of microfilament has no such effect. We assume that the dynamic polymerization of microtubules should be responsible to the transportation of TPE-11. More importantly, we found that the interaction between TPE-11 and microtubule proteins also happens during process of polymerization in vitro. The intracellular trafficking of TPE-11 by microtubules may be generalized to other amphiphilic molecules as well as endocytosis pathway, and serves as references in designing functional molecules involved in the intracellular transportation.