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In vivo and in vitro Studies of Adaptor-clathrin Interaction
Published on: January 26, 2011
Interaction of two structurally distinct sequence types with the clathrin terminal domain beta-propeller
1Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
The Journal of Biological Chemistry
|May 31, 2001
Summary
Researchers discovered two distinct clathrin-binding sequences on endocytic proteins. These sequences, type I and type II, cooperate to enhance clathrin bud formation during endocytosis.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Clathrin heavy chain's amino-terminal domain mediates protein interactions via LLDLD motifs.
- Endocytic proteins like amphiphysin and epsin bind to clathrin.
Purpose of the Study:
- To analyze and characterize a second, distinct clathrin-binding sequence (type II) in endocytic proteins.
- To investigate the cooperative binding of type I and type II sequences to clathrin.
Main Methods:
- Analysis of type II clathrin-binding sequences, including (257)LMDLA in rat epsin 1 and (417)PWDLW in human amphiphysin II.
- Investigating the structural features required for type II sequence association with clathrin.
- Assessing the cooperative binding of type I and type II sequences in amphiphysin.
Main Results:
- Identified type II sequences with structural features distinct from LLDLD-based type I sequences.
- Showed that the (257)LMDLA sequence is a weaker variant of the (417)PWDLW sequence.
- Demonstrated cooperation between type I and type II sequences in amphiphysin for optimal clathrin binding and assembly formation.
Conclusions:
- Endocytic accessory proteins possess two distinct interaction surfaces for clathrin binding.
- These cooperative interactions enhance clathrin bud formation at the cell surface by interacting with other coat components.
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