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GEF-effector interactions.
| Content Provider | Europe PMC |
|---|---|
| Author | Jackson, Catherine L |
| Copyright Year | 2014 |
| Abstract | Members of the Arf family of small GTP-binding proteins, or GTPases, are activated by guanine nucleotide exchange factors (GEFs) that catalyze GDP release from their substrate Arf, allowing GTP to bind. In the secretory pathway, Arf1 is first activated by GBF1 at the cis-Golgi, then by BIG1 and BIG2 at the trans-Golgi and trans-Golgi network (TGN). Upon activation, Arf1-GTP interacts with effectors such as coat complexes, and is able to recruit different coat complexes to different membrane sites in cells. The COPI coat is primarily recruited to cis-Golgi membranes, whereas other coats, such as AP-1/clathrin, and GGA/clathrin, are recruited to the trans-Golgi and the TGN. Although Arf1-GTP is required for stable association of these various coats to membranes, and is sufficient in vitro, other molecules, such as vesicle cargo and coat receptors on the membrane, contribute to specificity of coat recruitment in cells. Another mechanism to achieve specificity is interaction of effectors such as coats with the GEF itself, which would increase the concentration of a given coat in proximity to the site where Arf is activated, thus favoring its recruitment. This interaction between a GEF and an effector could also provide a mechanism for spatial organization of vesicle budding sites, similar to that described for Cdc42-mediated establishment of polarity sites such as the emerging bud in yeast. Another factor affecting the amount of freely diffusible Arf1-GTP in membranes is the GEF(s) themselves acting as effectors. Sec7p, the yeast homolog of mammalian BIG1 and BIG2, and Arno/cytohesin 2, a PM-localized Arf1 GEF, both bind to Arf1-GTP. This binding to the products of the exchange reaction establishes a positive feedback loop for activation. |
| Related Links | https://europepmc.org/backend/ptpmcrender.fcgi?accid=PMC4279777&blobtype=pdf |
| Page Count | 3 |
| ISSN | 21592780 |
| Volume Number | 4 |
| DOI | 10.4161/21592780.2014.943616 |
| PubMed Central reference number | PMC4279777 |
| Issue Number | 2 |
| PubMed reference number | 25610717 |
| Journal | Cellular Logistics [Cell Logist] |
| e-ISSN | 21592799 |
| Language | English |
| Publisher | Taylor & Francis |
| Publisher Date | 2014-04-01 |
| Access Restriction | Open |
| Rights License | This is an Open Access article distributed under the terms of the Creative Commons Attribution-Non-Commercial License http://creativecommons.org/licenses/by-nc/3.0/, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The moral rights of the named author(s) have been asserted. © 2014 The Author(s). Published with license by Taylor & Francis Group, LLC |
| Subject Keyword | ADP-ribosylation factor (Arf) Cdc42 Golgi Brefeldin A resistant guanine nucleotide exchange Factor 1 (GBF1) Guanine nucleotide exchange factor (GEF) Sec7 Turing-type mechanism vesicle budding |
| Content Type | Text |
| Resource Type | Article |
| Subject | Cardiology and Cardiovascular Medicine |
