| Structural highlights
Function
ARF6_HUMAN GTP-binding protein involved in protein trafficking; regulates endocytic recycling and cytoskeleton remodeling. May modulate vesicle budding and uncoating within the Golgi apparatus. Functions as an allosteric activator of the cholera toxin catalytic subunit, an ADP-ribosyltransferase. Involved in the regulation of dendritic spine development (By similarity). Contributes to the regulation of dendritic branching and filopodia extension.[1] [2] [3]
Publication Abstract from PubMed
ADP-Ribosylation Factor (ARF) small GTPases have been found to act in vesicle fission through a direct ability to tubulate membrane. We have pursued cryoelectron microscopy (EM) to reveal at 3.9 A resolution how ARF6 assembles into a protein lattice on tubulated membrane. Molecular dynamics simulation studies confirm and extend the cryo-EM findings. The ARF6 lattice exhibits features that are distinct from those formed by other membrane-bending proteins. We identify protein contacts critical for lattice assembly and how membrane insertion results in constricted tubules. The lattice structure also enables docking by GTPase-activating proteins (GAP) to achieve vesiculation. We have also modeled ARF1 onto the ARF6 lattice, and then pursued vesicle reconstitution by the Coat Protein I (COPI) complex to further confirm that the ARF lattice acts in vesicle fission. By elucidating how an ARF protein tubulates membrane at the structural level, we have advanced the molecular understanding of how this class of transport factors promote the fission stage of vesicle formation.
Structural elucidation of how ARF small GTPases induce membrane tubulation for vesicle fission.,Pang X, Zhang Y, Park K, Liao Z, Li J, Xu J, Hong MT, Yin G, Zhang T, Wang Y, Egelman EH, Fan J, Hsu VW, Park SY, Sun F Proc Natl Acad Sci U S A. 2025 Mar 25;122(12):e2417820122. doi: , 10.1073/pnas.2417820122. Epub 2025 Mar 21. PMID:40117306[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ D'Souza-Schorey C, Stahl PD. Myristoylation is required for the intracellular localization and endocytic function of ARF6. Exp Cell Res. 1995 Nov;221(1):153-9. PMID:7589240 doi:http://dx.doi.org/10.1006/excr.1995.1362
- ↑ Gauthier-Campbell C, Bredt DS, Murphy TH, El-Husseini Ael-D. Regulation of dendritic branching and filopodia formation in hippocampal neurons by specific acylated protein motifs. Mol Biol Cell. 2004 May;15(5):2205-17. Epub 2004 Feb 20. PMID:14978216 doi:10.1091/mbc.E03-07-0493
- ↑ Pasqualato S, Menetrey J, Franco M, Cherfils J. The structural GDP/GTP cycle of human Arf6. EMBO Rep. 2001 Mar;2(3):234-8. PMID:11266366 doi:10.1093/embo-reports/kve043
- ↑ Pang X, Zhang Y, Park K, Liao Z, Li J, Xu J, Hong MT, Yin G, Zhang T, Wang Y, Egelman EH, Fan J, Hsu VW, Park SY, Sun F. Structural elucidation of how ARF small GTPases induce membrane tubulation for vesicle fission. Proc Natl Acad Sci U S A. 2025 Mar 25;122(12):e2417820122. PMID:40117306 doi:10.1073/pnas.2417820122
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