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Hanging the coat on a collar: Same function but different localization and mechanism for COPII
Yehonathan Malis1, Koret Hirschberg1, Christoph Kaether2
1Department of Pathology, Sackler School of Medicine, Tel-Aviv University, Tel Aviv, Israel.
Summary
A new model suggests the COPII coat complex forms a stationary collar at the ER exit site (ERES), not transport vesicles. This ERES then buds to form carriers for ER to Golgi transport.
Area of Science:
- Cell Biology
- Molecular Biology
- Membrane Trafficking
Background:
- The COPII coat complex is crucial for ER to Golgi transport, traditionally thought to form transport vesicles.
- Recent proposals challenge this dogma, suggesting a different mechanism and localization for COPII.
Purpose of the Study:
- To describe a newly proposed model for ER to Golgi transport.
- To detail the roles of essential proteins in this revised transport machinery.
Main Methods:
- Review and synthesis of recent findings on COPII complex function.
- Detailed description of protein-protein and protein-membrane interactions within the proposed model.
Main Results:
- The COPII complex is proposed to form a dynamic, stationary collar at the ER exit site (ERES).
- The ERES acts as a boundary and sorting hub for cargo.
- The ERES matures and buds into pleiomorphic carriers for transport to the Golgi.
Conclusions:
- This revised model shifts the understanding of COPII function from vesicle formation to defining the ERES.
- The fundamental protein interactions driving ER export remain largely consistent despite the mechanistic shift.
Keywords:
COPIIER exit sitecargo proteinearly secretory pathwayendoplasmic reticulumtransport carrierstransport vesiclesMore Related Videos
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