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-Structure paper
Title | TFG clusters COPII-coated transport carriers and promotes early secretory pathway organization. |
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Journal, issue, pages | EMBO J, Vol. 34, Issue 6, Page 811-827, Year 2015 |
Publish date | Mar 12, 2015 |
Authors | Adam Johnson / Nilakshee Bhattacharya / Michael Hanna / Janice G Pennington / Amber L Schuh / Lei Wang / Marisa S Otegui / Scott M Stagg / Anjon Audhya / |
PubMed Abstract | In mammalian cells, cargo-laden secretory vesicles leave the endoplasmic reticulum (ER) en route to ER-Golgi intermediate compartments (ERGIC) in a manner dependent on the COPII coat complex. We ...In mammalian cells, cargo-laden secretory vesicles leave the endoplasmic reticulum (ER) en route to ER-Golgi intermediate compartments (ERGIC) in a manner dependent on the COPII coat complex. We report here that COPII-coated transport carriers traverse a submicron, TFG (Trk-fused gene)-enriched zone at the ER/ERGIC interface. The architecture of TFG complexes as determined by three-dimensional electron microscopy reveals the formation of flexible, octameric cup-like structures, which are able to self-associate to generate larger polymers in vitro. In cells, loss of TFG function dramatically slows protein export from the ER and results in the accumulation of COPII-coated carriers throughout the cytoplasm. Additionally, the tight association between ER and ERGIC membranes is lost in the absence of TFG. We propose that TFG functions at the ER/ERGIC interface to locally concentrate COPII-coated transport carriers and link exit sites on the ER to ERGIC membranes. Our findings provide a new mechanism by which COPII-coated carriers are retained near their site of formation to facilitate rapid fusion with neighboring ERGIC membranes upon uncoating, thereby promoting interorganellar cargo transport. |
External links | EMBO J / PubMed:25586378 / PubMed Central |
Methods | EM (single particle) |
Resolution | 30.0 Å |
Structure data | EMDB-6075: EMDB-6076: |
Source |
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