9RTX

Mammalian AP3 complex on tubular membranes (ARF1 centered Beta3-ARF1 dimer-Beta3 interface)

9RTX の概要

• エントリーDOI: 10.2210/pdb9rtx/pdb
• EMDBエントリー: 54256
• 分子名称: AP-3 complex subunit beta, AP-3 complex subunit delta, ADP-ribosylation factor 1, ... (5 entities in total)
• 機能のキーワード: cargo adapter, coat, trafficking, endocytosis
• 由来する生物種: Pan troglodytes (chimpanzee); 詳細
• タンパク質・核酸の鎖数: 14
• 化学式量合計: 682352.45

構造登録者

Kaufman, J.G.G.,Tagiltsev, G.,Briggs, J.A.G.,Owen, D.J. (登録日: 2025-07-03, 公開日: 2026-05-27)

主引用文献

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.
Architecture of clathrin-independent AP3:ARF1-coated carriers.
Sci Adv, 12:eaed1529-eaed1529, 2026

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 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.

PubMed: 42139345
DOI: 10.1126/sciadv.aed1529

実験手法

ELECTRON MICROSCOPY (8.5 Å)