regulation of ER to Golgi vesicle-mediated transport

Definition

Target type: biologicalprocess

Any process that modulates the rate, frequency, or extent of ER to Golgi vesicle-mediated transport, the directed movement of substances from the endoplasmic reticulum (ER) to the Golgi, mediated by COP II vesicles. Small COP II coated vesicles form from the ER and then fuse directly with the cis-Golgi. Larger structures are transported along microtubules to the cis-Golgi. [GOC:dph, GOC:tb]

The regulation of ER to Golgi vesicle-mediated transport is a complex and tightly controlled process that ensures the efficient and accurate delivery of newly synthesized proteins and lipids from the endoplasmic reticulum (ER) to the Golgi apparatus. This journey is accomplished through a series of steps, each regulated by a specific set of molecular players.

1. **Cargo Selection and Packaging:**
- Proteins destined for the Golgi are typically modified in the ER, often with the addition of glycosylation tags.
- Cargo proteins are recognized by specific adaptor proteins (e.g., COPII coat proteins) that bind to both the cargo and the membrane of the ER.
- These adaptors assemble into a coat structure that deforms the ER membrane, forming a bud.

2. **Vesicle Budding and Formation:**
- The budding process is driven by GTPases (e.g., Sar1) that recruit and activate other COPII components.
- Once the coat is assembled, the membrane pinches off, forming a transport vesicle.
- The vesicle membrane is enriched with specific lipids (e.g., phosphatidylinositol 4-phosphate) that contribute to its curvature and identity.

3. **Vesicle Targeting and Fusion:**
- Vesicles move along microtubule tracks, driven by motor proteins (e.g., dynein and kinesin).
- Vesicles are targeted to specific compartments (e.g., the cis-Golgi network) based on the presence of tethering factors on the vesicle and target membrane.
- Tethering factors (e.g., golgins) bridge the gap between the vesicle and target membrane, facilitating fusion.

4. **Vesicle Fusion and Cargo Delivery:**
- Fusion of the vesicle with the target membrane is mediated by SNARE proteins, which are found on both the vesicle and target membranes.
- SNARE proteins interact in a specific manner to bring the two membranes into close proximity, promoting fusion.
- Once the vesicle fuses, the cargo proteins are released into the lumen of the Golgi compartment.

5. **Regulation by Signaling Pathways:**
- The entire process is tightly regulated by signaling pathways, including the Unfolded Protein Response (UPR) and the phosphoinositide signaling pathway.
- The UPR senses the accumulation of misfolded proteins in the ER and activates pathways that inhibit ER to Golgi transport, allowing for folding quality control.
- Phosphoinositide signaling regulates the activity of key players in vesicle formation and targeting, ensuring the correct distribution of cargo.

6. **Recycling of Vesicle Components:**
- After vesicle fusion, the COPII coat proteins are recycled back to the ER to be reused for new vesicle formation.
- This recycling process ensures the efficient and sustainable operation of the ER to Golgi transport pathway.

In summary, the regulation of ER to Golgi vesicle-mediated transport is a highly coordinated process that involves a complex interplay of proteins, lipids, and signaling pathways. This intricate mechanism ensures the accurate and efficient delivery of newly synthesized proteins and lipids to the Golgi apparatus, where they undergo further modification and sorting before reaching their final destinations.'
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Proteins (1)

Compounds (88)