Structural properties and peptide ligand binding of the capsid homology domains of human Arc

DOI: 10.1016/j.bbrep.2021.100975

Authors: Erik I. Hallin (University of Bergen) , Clive R. Bramham (University of Bergen) , Petri Kursula (University of Bergen; University of Oulu)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Biochemistry And Biophysics Reports , VOL 26

State: Published (Approved)
Published: July 2021
Diamond Proposal Number(s): 13440

Abstract: The activity-regulated cytoskeleton-associated protein (Arc) is important for synaptic plasticity and the normal function of the brain. Arc interacts with neuronal postsynaptic proteins, but the mechanistic details of its function have not been fully established. The C-terminal domain of Arc consists of tandem domains, termed the N- and C-lobe. The N-lobe harbours a peptide binding site, able to bind multiple targets. By measuring the affinity of human Arc towards various peptides from stargazin and guanylate kinase-associated protein (GKAP), we have refined its specificity determinants. We found two sites in the GKAP repeat region that bind to Arc and confirmed these interactions by X-ray crystallography. Phosphorylation of the stargazin peptide did not affect binding affinity but caused changes in thermodynamic parameters. Comparison of the crystal structures of three high-resolution human Arc-peptide complexes identifies three conserved C–H…π interactions at the binding cavity, explaining the sequence specificity of short linear motif binding by Arc. We further characterise central residues of the Arc lobe fold, show the effects of peptide binding on protein dynamics, and identify acyl carrier proteins as structures similar to the Arc lobes. We hypothesise that Arc may affect protein-protein interactions and phase separation at the postsynaptic density, affecting protein turnover and re-modelling of the synapse. The present data on Arc structure and ligand binding will help in further deciphering these processes.

Journal Keywords: Crystal structure; Specificity; Peptide binding; Postsynaptic density; Protein interaction; Capsid homology

Subject Areas: Biology and Bio-materials, Chemistry


Instruments: I03-Macromolecular Crystallography

Other Facilities: P13 and P14 at PETRA III

Added On: 10/03/2021 10:16

Documents:
1-s2.0-S2405580821000698-main.pdf

Discipline Tags:

Non-Communicable Diseases Health & Wellbeing Biochemistry Neurology Chemistry Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)