Mutation in the Kinase Domain Alters the VEGFR2 Membrane Dynamics.

Area of Science:

• Molecular biology
• Cell biology
• Biophysics

Background:

• The VEGFR2^R1051Q mutation is a cancer-associated gain-of-function mutation.
• VEGFR2^R1051Q exhibits ligand-independent phosphorylation, enhancing cell growth.
• Heterozygosity in cancer suggests VEGFR2^R1051Q interacts with wild-type VEGFR2 (VEGFR2^WT).

Purpose of the Study:

• To investigate the biophysical mechanism of VEGFR2^R1051Q activation.
• To determine how VEGFR2^R1051Q influences the dimerization and membrane dynamics of co-expressed VEGFR2^WT.

Main Methods:

• Utilized quantitative Fluorescence Lifetime Imaging Microscopy (FLIM)/Förster Resonance Energy Transfer (FRET) and Fluorescence Recovery After Photobleaching (FRAP).
• Employed Chinese Hamster Ovary (CHO) cells co-transfected with VEGFR2^R1051Q and VEGFR2^WT to mimic heterozygosity.

Main Results:

• Membrane protein biotinylation showed VEGFR2^WT is more exposed than VEGFR2^R1051Q.
• Imaging analyses confirmed VEGFR2^WT forms heterodimers with VEGFR2^R1051Q.
• Co-expression resulted in reduced lateral motility and a smaller mobile fraction of VEGFR2^WT.

Conclusions:

• Active VEGFR2^R1051Q impacts the membrane behavior of VEGFR2^WT.
• Heterodimerization between VEGFR2^R1051Q and VEGFR2^WT alters VEGFR2^WT membrane dynamics.