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Visualizing Clathrin-mediated Endocytosis of G Protein-coupled Receptors at Single-event Resolution via TIRF Microscopy
Published on: October 20, 2014
Dynamic interactions between clathrin and locally structured elements in a disordered protein mediate clathrin
Yue Zhuo1, Udayar Ilangovan, Virgil Schirf
1Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA.
Journal of Molecular Biology
|September 30, 2010
Summary
Clathrin assembly protein AP180
Area of Science:
- Cell biology
- Molecular biology
- Biochemistry
Background:
- Clathrin lattices mediate protein assembly.
- Assembly/adaptor proteins recruit clathrin via clathrin binding domains (CBDs).
- AP180 is a key clathrin assembly protein.
Purpose of the Study:
- To characterize the interaction between clathrin and the AP180 CBD.
- To define clathrin binding sites within AP180.
- To understand the structural dynamics of AP180 during clathrin binding.
Main Methods:
- Mutational analysis
- NMR chemical shift analysis
- Analytical ultracentrifugation
- Sequence analysis
- Circular dichroism
Main Results:
- Two weak clathrin binding sites were identified in the AP180 CBD fragment.
- AP180 CBD is largely unstructured but has localized beta-turn structures at binding sites.
- AP180 fragment remains unstructured upon binding to clathrin, unlike binding-coupled folding.
Conclusions:
- AP180 CBD contains multiple degenerate repeats with single clathrin binding sites.
- Weak, multi-site binding of pre-structured elements in an unstructured protein facilitates clathrin recruitment and lattice assembly.
- This mechanism enables efficient clathrin recruitment to endocytic sites and dynamic lattice assembly.
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