Journal Article

PreJuSER-60127

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Identification of clathrin heavy chain as a direct binding partner for the GABA type A receptor associated protein GABARAP

Mohrlüder, J.FZJ* ; Hoffmann, Y.FZJ* ; Stangler, T.FZJ* ; Hänel, K.FZJ* ; Willbold, D.FZJ*

2007
American Chemical Society Columbus, Ohio

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Please use a persistent id in citations: doi:10.1021/bi7018145

Abstract: Gamma-aminobutyric acid type A receptors (GABAA receptors) are the major sites of GABA-mediated fast synaptic inhibition in the central nervous system. Variation of the cell surface receptor count is postulated to be of importance in modulating inhibitory synaptic transmission. The GABAA receptor associated protein (GABARAP) is a ubiquitin-like modifier, implicated in GABAA receptor clustering, trafficking, and turnover. GABARAP pull-down experiments with brain lysate identified clathrin heavy chain to be GABARAP-associated. Phage display screening of a randomized peptide library for GABARAP ligands yielded a sequence motif which characterizes the peptide binding specificity of GABARAP. Sequence database searches with this motif revealed clathrin heavy chain as a protein containing the identified sequence motif within its residues 510-522, supporting the result of the pull-down experiments. Calreticulin, which was identified recently as a GABARAP ligand, contains a very similar sequence motif. We demonstrate that calreticulin indeed competes with clathrin heavy chain for GABARAP binding. Finally, employing nuclear magnetic resonance spectroscopy, we mapped the GABARAP residues responsible for binding to clathrin. The hereby mapped GABARAP regions overlap very well with the homologue residues in yeast Atg8 that were recently shown to be important for autophagy. Together with the knowledge that GABARAP and clathrin are known to be involved in GABAA receptor trafficking within the cell, this strongly suggests a clear physiological relevance of the direct interaction of GABARAP with clathrin heavy chain.

Keyword(s): Amino Acid Sequence (MeSH) ; Calreticulin: chemistry (MeSH) ; Calreticulin: metabolism (MeSH) ; Clathrin Heavy Chains: chemistry (MeSH) ; Clathrin Heavy Chains: genetics (MeSH) ; Clathrin Heavy Chains: metabolism (MeSH) ; Magnetic Resonance Spectroscopy (MeSH) ; Models, Molecular (MeSH) ; Molecular Sequence Data (MeSH) ; Protein Binding (MeSH) ; Protein Structure, Tertiary (MeSH) ; Receptors, GABA-A: chemistry (MeSH) ; Receptors, GABA-A: genetics (MeSH) ; Receptors, GABA-A: metabolism (MeSH) ; Sequence Homology, Amino Acid (MeSH) ; Calreticulin ; Receptors, GABA-A ; Clathrin Heavy Chains ; J

Note: Record converted from VDB: 12.11.2012

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Contributing Institute(s):

1. Molekulare Biophysik (INB-2)
2. Jülich-Aachen Research Alliance - Simulation Sciences (JARA-SIM)

Research Program(s):

1. Funktion und Dysfunktion des Nervensystems (P33)

Appears in the scientific report 2007

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