For the first time, researchers have directly visualized how newly formed cellular organelles leave the endoplasmic reticulum (ER) and transition onto microtubule tracks inside living cells. This new finding reveals that the ER plays an active and dynamic role in steering intracellular traffic rather than serving as a passive factory. The study is published in the journal ACS Nano.
For the study led by Director Cho Minhaeng at the Center for Molecular Spectroscopy and Dynamics within the Institute for Basic Science and Professor Hong Seok-Cheol at Korea University, the research team captured in real time the moment an autophagosome—an organelle responsible for cellular recycling—moves from the ER onto a neighboring microtubule. This long-sought observation provides direct experimental evidence for how intracellular transport is coordinated at nanoscopic contact sites within the crowded environment of living cells.
Autophagy is an essential cellular process in which damaged proteins and aged organelles are enclosed by double-membrane structures and delivered for degradation and recycling. The importance of autophagy was recognized by the 2016 Nobel Prize in Physiology or Medicine awarded to Yoshinori Ohsumi. Although scientists have long proposed that autophagosomes are transferred from the ER to microtubules at specialized contact sites, direct real-time experimental evidence of this cellular “handoff” had remained out of reach—until now.
