Related Experiment Video
Updated: Jun 27, 2026

Computational Prediction of Amino Acid Preferences of Potentially Multispecific Peptide-Binding Domains Involved in Protein-Protein Interactions
Published on: January 26, 2024
The postsynaptic density protein, IQ-ArfGEF/BRAG1, can interact with IRSp53 through its proline-rich sequence
Masashi Sanda1, Akifumi Kamata, Osamu Katsumata
1Department of Anatomy, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555, Japan.
IQ-ArfGEF/BRAG1 interacts with IRSp53 at the postsynaptic density, suggesting a role in synaptic function downstream of NMDA receptors. This interaction involves specific protein domains and occurs in certain neurons.
Area of Science:
- Neuroscience
- Molecular Biology
- Cell Biology
Background:
- IQ-ArfGEF/BRAG1 is a guanine nucleotide exchange factor localized to the postsynaptic density (PSD) and known to interact with PSD-95.
- The PSD is a critical protein complex at excitatory synapses, involved in synaptic plasticity and function.
Purpose of the Study:
- To identify novel interaction partners of IQ-ArfGEF/BRAG1.
- To investigate the functional implications of IQ-ArfGEF/BRAG1 interactions within the PSD.
Main Methods:
- Protein-protein interaction assays to identify binding partners.
- Co-localization studies using immunohistochemistry in neuronal populations.
- Analysis of specific protein domain interactions.
Main Results:
- A novel interaction between IQ-ArfGEF/BRAG1 and insulin receptor tyrosine kinase substrate of 53 kDa (IRSp53) was identified.
- The interaction is mediated by the C-terminal proline-rich sequence of IQ-ArfGEF/BRAG1 binding to the SH3 domain of IRSp53.
- Both proteins were found to co-localize at the PSD of specific excitatory neuronal populations.
Conclusions:
- IQ-ArfGEF/BRAG1 interacts with IRSp53, another PSD-localized protein.
- This interaction suggests IQ-ArfGEF/BRAG1 may function downstream of NMDA receptors via interactions with multivalent PSD proteins like IRSp53 and PSD-95.
More Related Videos
12:44Electrophoretic Mobility Shift Assay (EMSA) for the Study of RNA-Protein Interactions: The IRE/IRP Example
Published on: December 3, 2014
05:43A Protein Preparation Method for the High-throughput Identification of Proteins Interacting with a Nuclear Cofactor Using LC-MS/MS Analysis
Published on: January 24, 2017
Related Concept Videos
Regulation of the Unfolded Protein Response
Directing Proteins to the Rough Endoplasmic Reticulum
Assembly of Signaling Complexes
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
IP3/DAG Signaling Pathway
Mechanism of Filopodia Formation
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Generation of Straight or Branched Actin Filaments
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...