Visualization of cargo sorting system in the trans-Golgi network

March 26, 2021

The hub for material transportation in cells is distinctly zoned

A collaborative study group including RIKEN Center for Advanced Photonics, RIKEN CSRS, and Ochanomizu University found independent two zones responsible for protein transport to different final destinations in the single "trans-Golgi network (TGN)".

"Cargo proteins" newly synthesized in endoplasmic reticulum are delivered into the Golgi apparatus to be modified and transferred to TGN. TGN plays an important role as a hub of protein transport pathways in the cells by sorting out various cargo proteins and sending them to their final destinations such as plasma membrane, extracellular space and vacuoles, where each of the proteins is supposed to work. It remained unclear, however, how the TGN sorts out multiple cargo proteins by their final destinations simultaneously.

In this research, the group examined precise localization and dynamics of "cargo proteins destined to the plasma membrane or vacuolar membrane" and "coat proteins responsible for cargo sorting"localized in the TGN in plant cells using the super-resolution confocal live imaging microscopy (SCLIM) developed by this research group. The results demonstrated that there are separate zones specialized in sorting of cargo proteins destined to the plasma membrane or vacuolar membrane in the single TGN.

The findings of this study demonstrated the hypothesis that TGN functions as a region for sorting proteins into multiple transport pathways, which has been proposed in the past. They will form a basis of further studies of intracellular protein transport.

Original article
Nature Communications doi:10.1038/s41467-021-22267-0
Y. Shimizu, J. Takagi, E. Ito, Y. Ito, K. Ebine, Y. Komatsu, Y. Goto, M. Sato, K. Toyooka, T. Ueda, K. Kurokawa, T. Uemura, A. Nakano,
"Cargo sorting zones in the trans-Golgi network visualized by super-resolution confocal live imaging microscopy in plants".
Kiminori Toyooka
Senior Technical Scientist
Mass Spectrometry and Microscopy Unit