Rab7-harboring vesicles are carriers of the transferrin receptor through the biosynthetic secretory pathway

The biosynthetic secretory pathway is particularly challenging to investigate as it is underrepresented compared to the abundance of the other intracellular trafficking routes. Here, we combined the retention using selective hook (RUSH) to a CRISPR-Cas9 gene editing approach (eRUSH) and identified Rab7-harboring vesicles as an important intermediate compartment of the Golgi-to-plasma membrane transport of neosynthesized transferrin receptor (TfR). These vesicles did not exhibit degradative properties and were not associated to Rab6A-harboring vesicles. Rab7A was transiently associated to neosynthetic TfR-containing post-Golgi vesicles but dissociated before fusion with the plasma membrane. Together, our study reveals a role for Rab7 in the biosynthetic secretory pathway of the TfR, highlighting the diversity of the secretory vesicles' nature.

Automated summary

The study combined RUSH and eRUSH methods and identified Rab7-harboring vesicles as important intermediates in the Golgi-to-plasma membrane transport of TfR. Rab7 was found to transiently associate with neosynthetic TfR-containing post-Golgi vesicles before dissociation before fusion with the plasma membrane, revealing the diversity of secretory vesicles.