Early/recycling endosomes-to-TGN transport involves two SNARE complexes and a Rab6 isoform.
The molecular mechanisms underlying early/recycling endosomes-to-TGN transport are still not understood. We identified interactions between the TGN-localized putative t-SNAREs syntaxin 6, syntaxin 16, and Vti1a, and two early/recycling endosomal v-SNAREs, VAMP3/cellubrevin, and VAMP4. Using a novel permeabilized cell system, these proteins were functionally implicated in the post-Golgi retrograde transport step. The function of Rab6a' was also required, whereas its closely related isoform, Rab6a, has previously been implicated in Golgi-to-endoplasmic reticulum transport. Thus, our study shows that membrane exchange between the early endocytic and the biosynthetic/secretory pathways involves specific components of the Rab and SNARE machinery, and suggests that retrograde transport between early/recycling endosomes and the endoplasmic reticulum is critically dependent on the sequential action of two members of the Rab6 subfamily.
Pubmed ID: 11839770 RIS Download
Animals | Biological Transport, Active | CHO Cells | Carrier Proteins | Cricetinae | Endosomes | HeLa Cells | Humans | Membrane Proteins | Protein Isoforms | Qa-SNARE Proteins | Qb-SNARE Proteins | SNARE Proteins | Shiga Toxins | Syntaxin 16 | Vesicle-Associated Membrane Protein 3 | Vesicular Transport Proteins | rab GTP-Binding Proteins | trans-Golgi Network