Architecture of clathrin-independent AP3:ARF1-coated carriers
Kaufman JGG, Tagiltsev G, Stalder DS, Taylor RJ, Sava I, Guo H, Ciazynska KA, Zaccai NR, Gray SR, Vallis Y, Höning S, Kelly BT, Gershlick DC, Briggs JAG, Owen DJ. 2026. Architecture of clathrin-independent AP3:ARF1-coated carriers. Science Advances. 12(20), eaed1529.
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Journal Article
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| English
Scopus indexed
Author
Kaufman, Jonathan G.G.;
Tagiltsev, Grigory;
Stalder, Danièle S.;
Taylor, Rebecca J.;
Sava, Ioana;
Guo, Hui;
Ciazynska, Katarzyna A.;
Zaccai, Nathan R.;
Gray, Sally R.;
Vallis, YvonneISTA 
;
Höning, Stefan;
Kelly, Bernard T.
All
;
Höning, Stefan;
Kelly, Bernard T.
All
Department
Abstract
The AP3 complex mediates cargo sorting and carrier assembly for the trafficking of transmembrane proteins from endosomes to lysosomes. AP3 is generally believed to localize to clathrin-free, ARF1-positive, elongated carriers in cells, but the architecture of AP3-based coats was unknown. Using in vitro reconstitution and cryo–electron tomography, we demonstrate that AP3:ARF1 spontaneously remodels membranes containing cargo and the phosphoinositide PI(3,5)P
<jats:sub>2</jats:sub>
into tubular structures coated in spiraling rows of AP3 arches and ARF1 dimers. Targeted point mutations disrupting critical AP3:ARF1 and AP3:AP3 lattice interfaces disrupt AP3 recruitment, carrier formation, and lysosomal cargo trafficking in cells. We propose that AP3 generates tubular carriers on endosomes by organizing ARF1 dimers into elongated membrane-deforming arrays while simultaneously selecting cargo. By demonstrating that AP3:ARF1 can generate carriers without using a clathrin lattice, we explain the clathrin independence of AP3-mediated trafficking.
Publishing Year
Date Published
2026-05-15
Journal Title
Science Advances
Publisher
American Association for the Advancement of Science
Acknowledgement
We thank P. Luzio, N. Bright, and M. S. Robinson for helpful discussions;
J. Stacey and Y. Fujiharu for technical discussions and assistance; F. Beck for assistance with
computing infrastructure; and M. Riggi for discussion of data presentation and figure design.
Cryo-E
M data was collected at the Department of Cell and Virus Structure, Max Planck Institute
of Biochemistry. Funding: This work was funded by: the Wellcome Trust, Wellcome Discovery
Award 227915/Z/23/Z (to D.J.O., J.A.G.B., and D.G.S.) and Wellcome PRF 207455/Z/17/Z (to
D.J.O.); the Max Planck Society (to J.A.G.B.); the Medical Research Council (UKRI) MC_
UP_1201/16 (to J.A.G.B.) and MRC DT P MR/N013433/1 (to J.G.G.K.); EMBO Long-term
Postdoctoral Fellowship ALT F-383-
2022
(to G.T.); and the Wellcome Trust/Royal Society, Sir
Henry Dale Fellowship 210481 (to D.C.G) and the Biotechnology and Biological Sciences
Research Council (UKRI) responsive mode grants BB/W005905/1 and UKRI715 (to D.C.G.).
Volume
12
Issue
20
Article Number
eaed1529
eISSN
IST-REx-ID
Cite this
Kaufman JGG, Tagiltsev G, Stalder DS, et al. Architecture of clathrin-independent AP3:ARF1-coated carriers. Science Advances. 2026;12(20). doi:10.1126/sciadv.aed1529
Kaufman, J. G. G., Tagiltsev, G., Stalder, D. S., Taylor, R. J., Sava, I., Guo, H., … Owen, D. J. (2026). Architecture of clathrin-independent AP3:ARF1-coated carriers. Science Advances. American Association for the Advancement of Science. https://doi.org/10.1126/sciadv.aed1529
Kaufman, Jonathan G.G., Grigory Tagiltsev, Danièle S. Stalder, Rebecca J. Taylor, Ioana Sava, Hui Guo, Katarzyna A. Ciazynska, et al. “Architecture of Clathrin-Independent AP3:ARF1-Coated Carriers.” Science Advances. American Association for the Advancement of Science, 2026. https://doi.org/10.1126/sciadv.aed1529.
J. G. G. Kaufman et al., “Architecture of clathrin-independent AP3:ARF1-coated carriers,” Science Advances, vol. 12, no. 20. American Association for the Advancement of Science, 2026.
Kaufman JGG, Tagiltsev G, Stalder DS, Taylor RJ, Sava I, Guo H, Ciazynska KA, Zaccai NR, Gray SR, Vallis Y, Höning S, Kelly BT, Gershlick DC, Briggs JAG, Owen DJ. 2026. Architecture of clathrin-independent AP3:ARF1-coated carriers. Science Advances. 12(20), eaed1529.
Kaufman, Jonathan G. G., et al. “Architecture of Clathrin-Independent AP3:ARF1-Coated Carriers.” Science Advances, vol. 12, no. 20, eaed1529, American Association for the Advancement of Science, 2026, doi:10.1126/sciadv.aed1529.
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