Dissection of GTPase activating proteins reveals functional asymmetry in the COPI coat

Arakel, Eric C. and Huranova, Martina and Estrada, Alejandro F. and Rau, E-Ming and Spang, Anne and Schwappach, Blanche. (2019) Dissection of GTPase activating proteins reveals functional asymmetry in the COPI coat. Journal of cell science, ahead of print. pp. 1-54.

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The Arf GTPase controls formation of the COPI vesicle coat. Recent structural models of COPI revealed the positioning of two Arf1 molecules in contrasting molecular environments. Each of these pockets for Arf1 is expected to also accommodate an Arf GTPase-activating protein (ArfGAP). Structural evidence and protein interactions observed between isolated domains indirectly suggests that each niche may preferentially recruit one of the two ArfGAPs known to affect COPI, Gcs1/ArfGAP1 and Glo3/ArfGAP2/3, although only partial structures are available. The functional role of the unique non-catalytic domain of either ArfGAP has not been integrated into the current COPI structural model. Here, we delineate key differences in the consequences of triggering GTP hydrolysis via the activity of one versus the other ArfGAP. We demonstrate that Glo3/ArfGAP2/3 specifically triggers Arf1 GTP hydrolysis impinging on the stability of the COPI coat. We show that the yeast homologue of AMP kinase, Snf1, phosphorylates the region of Glo3 that is critical for this effect and thereby regulates its function in the COPI-vesicle cycle. Our results revise the model of ArfGAP function in the molecular context of COPI.
Faculties and Departments:05 Faculty of Science > Departement Biozentrum > Growth & Development > Biochemistry (Spang)
UniBasel Contributors:Spang, Anne
Item Type:Article, refereed
Article Subtype:Research Article
Publisher:Company of Biologists
Note:Publication type according to Uni Basel Research Database: Journal article
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Last Modified:19 Aug 2019 15:26
Deposited On:19 Aug 2019 15:26

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