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Updated: Sep 30, 2025
10:52
A High-content Imaging Workflow to Study Grb2 Signaling Complexes by Expression Cloning
Published on: October 30, 2012
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Interdomain interactions in Grb2 revealed by the conformational stability and CD28 binding analysis.
Saki Ochi1, Momoka Iiyama1, Masayuki Oda1
1Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, 1-5 Hangi-cho, Shimogamo, Sakyo-ku, Kyoto, Kyoto 606-8522, Japan.
Biophysical Chemistry
|March 11, 2022
Summary
Growth-factor receptor-bound protein 2 (Grb2) adaptor protein SH3 domains are crucial for binding to the CD28 receptor. These domains also contribute to Grb2’s structural stability, as revealed by binding affinity and thermal stability studies.
Area of Science:
- Molecular Biology
- Immunology
- Biochemistry
Background:
- Growth-factor receptor-bound protein 2 (Grb2) is a key adaptor protein in cellular signal transduction pathways.
- Grb2 possesses a modular structure comprising a central SH2 domain flanked by N-terminal (nSH3) and C-terminal (cSH3) SH3 domains.
Purpose of the Study:
- To investigate the role of Grb2's SH3 domains in its interaction with the cytoplasmic region of the CD28 receptor.
- To evaluate the contribution of SH3 domains to the overall structural stability of Grb2.
Main Methods:
- Surface plasmon resonance (SPR) was employed to quantify the binding affinity of Grb2 and its SH3-deletion mutants (Grb2_nSH3del, Grb2_cSH3del) to CD28.
- Differential scanning calorimetry (DSC) was utilized to assess the thermal stabilities of Grb2 and its mutants.
Main Results:
- Both Grb2_nSH3del and Grb2_cSH3del exhibited altered CD28 binding affinities compared to wild-type Grb2, indicating SH3 domain involvement in binding.
- Thermal stability analysis revealed that SH3 domains, particularly the nSH3 domain, significantly contribute to Grb2's structural integrity.
Conclusions:
- At least one SH3 domain of Grb2 is essential for effective binding to the CD28 receptor.
- The SH3 domains play a critical role in stabilizing the Grb2 protein structure, likely through interdomain interactions.
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