Download MendeleyArchitecture of clathrin-independent AP3:ARF1-coated carriers.
Kaufman, J.G.G., Tagiltsev, G., Stalder, D.S., Taylor, R.J., Sava, I., Guo, H., Ciazynska, K.A., Zaccai, N.R., Gray, S.R., Vallis, Y., Honing, S., Kelly, B.T., Gershlick, D.C., Briggs, J.A.G., Owen, D.J.(2026) Sci Adv 12: eaed1529-eaed1529
- PubMed: 42139345 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.1126/sciadv.aed1529
- Primary Citation Related Structures:
9RTW, 9RTX, 9RTY, 9RTZ - PubMed 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 2 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.
- Cambridge Institute for Medical Research, Cambridge Biomedical Campus, Cambridge CB2 0XY, UK.
Organizational Affiliation:
