Details

Autor(en) / Beteiligte

• Jackson, Lauren P.
• Kelly, Bernard T.
• McCoy, Airlie J.
• Gaffry, Thomas
• James, Leo C.
• Collins, Brett M.
• Höning, Stefan
• Evans, Philip R.
• Owen, David J.

Titel

A Large-Scale Conformational Change Couples Membrane Recruitment to Cargo Binding in the AP2 Clathrin Adaptor Complex

Ist Teil von

• Cell, 2010-06, Vol.141 (7), p.1220-1229

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2010

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• The AP2 adaptor complex (α, β2, σ2, and μ2 subunits) crosslinks the endocytic clathrin scaffold to PtdIns4,5P2-containing membranes and transmembrane protein cargo. In the “locked” cytosolic form, AP2's binding sites for the two endocytic motifs, YxxΦ on the C-terminal domain of μ2 (C-μ2) and [ED]xxxL[LI] on σ2, are blocked by parts of β2. Using protein crystallography, we show that AP2 undergoes a large conformational change in which C-μ2 relocates to an orthogonal face of the complex, simultaneously unblocking both cargo-binding sites; the previously unstructured μ2 linker becomes helical and binds back onto the complex. This structural rearrangement results in AP2's four PtdIns4,5P2- and two endocytic motif-binding sites becoming coplanar, facilitating their simultaneous interaction with PtdIns4,5P2/cargo-containing membranes. Using a range of biophysical techniques, we show that the endocytic cargo binding of AP2 is driven by its interaction with PtdIns4,5P2-containing membranes. [Display omitted] ► The cargo-binding sites of the AP2 clathrin adaptor are blocked in its cytosolic form ► The crystal structure of AP2's cargo-liganded form reveals a large conformational change ► AP2′s two cargo and four PtdIns4,5P2-binding sites become coplanar ► Association with a PtdIns4,5P2-containing membrane drives AP2's conformational change