Related Experiment Video
Updated: Dec 24, 2025
Detection of Heterodimerization of Protein Isoforms Using an in Situ Proximity Ligation Assay
Published on: October 20, 2018
Single-molecule functional anatomy of endogenous HER2-HER3 heterodimers
Byoungsan Choi1,2, Minkwon Cha2, Gee Sung Eun1
1School of Biological Sciences and Institute for Molecular Biology and Genetics, Seoul National University, Seoul, Republic of Korea.
Abstract:
Human epidermal growth factor receptors (HERs) are the primary targets of many directed cancer therapies. However, the reason a specific dimer of HERs generates a stronger proliferative signal than other permutations remains unclear. Here, we used single-molecule immunoprecipitation to develop a biochemical assay for endogenously-formed, entire HER2-HER3 heterodimers. We observed unexpected, large conformational fluctuations in juxta-membrane and kinase domains of the HER2-HER3 heterodimer. Nevertheless, the individual HER2-HER3 heterodimers catalyze tyrosine phosphorylation at an unusually high rate, while simultaneously interacting with multiple copies of downstream signaling effectors. Our results suggest that the high catalytic rate and multi-tasking capability make a concerted contribution to the strong signaling potency of the HER2-HER3 heterodimers.
Insights
The HER2-HER3 heterodimer exhibits significant conformational changes and a high catalytic rate for tyrosine phosphorylation. This, along with its ability to interact with multiple signaling proteins, explains its potent cancer-promoting signaling activity.
Area of Science:
- Biochemistry
- Molecular Biology
- Cancer Research
Background:
- Human epidermal growth factor receptors (HERs) are key targets in cancer therapy.
- The signaling mechanisms of specific HER dimer permutations, like HER2-HER3, are not fully understood.
Purpose of the Study:
- To investigate the biochemical properties of endogenously formed HER2-HER3 heterodimers.
- To elucidate the molecular basis for the potent proliferative signaling of HER2-HER3.
Main Methods:
- Development of a biochemical assay using single-molecule immunoprecipitation.
- Analysis of conformational dynamics and catalytic activity of HER2-HER3 heterodimers.
Main Results:
- Observed significant conformational fluctuations in HER2-HER3 juxta-membrane and kinase domains.
- Demonstrated a high rate of tyrosine phosphorylation catalyzed by individual HER2-HER3 heterodimers.
- Showcased simultaneous interaction of HER2-HER3 with multiple downstream signaling effectors.
Conclusions:
- The high catalytic rate and multi-tasking capability of HER2-HER3 heterodimers contribute to their strong signaling potency.
- Understanding these mechanisms may inform the development of more effective targeted cancer therapies.
More Related Videos
09:07Detecting the Ligand-binding Domain Dimerization Activity of Estrogen Receptor Alpha Using the Mammalian Two-Hybrid Assay
Published on: December 19, 2018
11:34Building Up a High-throughput Screening Platform to Assess the Heterogeneity of HER2 Gene Amplification in Breast Cancers
Published on: December 5, 2017