scholarly journals Fluorescence resonance energy transfer based quantitative analysis of feedforward and feedback loops in epidermal growth factor receptor signaling and the sensitivity to molecular targeting drugs

FEBS Journal ◽  
2014 ◽  
Vol 281 (14) ◽  
pp. 3177-3192 ◽  
Author(s):  
Yoshihisa Fujita ◽  
Naoki Komatsu ◽  
Michiyuki Matsuda ◽  
Kazuhiro Aoki
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Energy Transfer ◽  
Quantitative Analysis ◽  
Resonance Energy Transfer ◽  
Growth Factor Receptor ◽  
Resonance Energy ◽  
Feedback Loops ◽  
Molecular Targeting ◽  
Epidermal Growth ◽  
Growth Factor Receptor Signaling

scholarly journals Enhanced dimerization drives ligand-independent activity of mutant epidermal growth factor receptor in lung cancer

2015 ◽  
Vol 26 (22) ◽  
pp. 4087-4099 ◽  
Author(s):  
Christopher C. Valley ◽  
Donna J. Arndt-Jovin ◽  
Narain Karedla ◽  
Mara P. Steinkamp ◽  
Alexey I. Chizhik ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Resonance Energy Transfer ◽  
Growth Factor Receptor ◽  
Resonance Energy ◽  
Epidermal Growth

Mutations within the epidermal growth factor receptor (EGFR/erbB1/Her1) are often associated with tumorigenesis. In particular, a number of EGFR mutants that demonstrate ligand-independent signaling are common in non–small cell lung cancer (NSCLC), including kinase domain mutations L858R (also called L834R) and exon 19 deletions (e.g., ΔL747-P753insS), which collectively make up nearly 90% of mutations in NSCLC. The molecular mechanisms by which these mutations confer constitutive activity remain unresolved. Using multiple subdiffraction-limit imaging modalities, we reveal the altered receptor structure and interaction kinetics of NSCLC-associated EGFR mutants. We applied two-color single quantum dot tracking to quantify receptor dimerization kinetics on living cells and show that, in contrast to wild-type EGFR, mutants are capable of forming stable, ligand-independent dimers. Two-color superresolution localization microscopy confirmed ligand-independent aggregation of EGFR mutants. Live-cell Förster resonance energy transfer measurements revealed that the L858R kinase mutation alters ectodomain structure such that unliganded mutant EGFR adopts an extended, dimerization-competent conformation. Finally, mutation of the putative dimerization arm confirmed a critical role for ectodomain engagement in ligand-independent signaling. These data support a model in which dysregulated activity of NSCLC-associated kinase mutants is driven by coordinated interactions involving both the kinase and extracellular domains that lead to enhanced dimerization.

Sign in / Sign up

Export Citation Format

Share Document