VEGF receptor 2 endocytic trafficking regulates arterial morphogenesis

Area of Science:

• Molecular biology
• Cell biology
• Developmental biology

Background:

• Vascular endothelial growth factor (VEGF) is essential for arterial morphogenesis.
• The precise molecular mechanisms governing VEGF-mediated arterial development remain unclear.
• Synectin deficiency impairs VEGF signaling and arterial formation.

Purpose of the Study:

• To elucidate the molecular events underlying VEGF-driven arterial morphogenesis.
• To investigate the role of synectin and myosin-VI in VEGFR2 trafficking and activation.
• To identify therapeutic targets for restoring arterial development.

Main Methods:

• Utilized synectin null mice and myosin-VI knockout mice/zebrafish models.
• Investigated VEGFR2 trafficking, phosphorylation, and dephosphorylation dynamics.
• Employed gene silencing techniques (PTP1b, myosin-VI) to assess functional recovery.

Main Results:

• Synectin null mice exhibit delayed VEGFR2 endosomal trafficking, leading to VEGFR2 dephosphorylation at Y1175 by PTP1b.
• Myosin-VI is critical for synectin-mediated VEGFR2 trafficking.
• Silencing PTP1b rescues VEGFR2 activation and arterial morphogenesis in synectin/myosin-VI deficient models.
• VEGFR2 Y1175 phosphorylation, dependent on intracellular trafficking, is vital for VEGF signaling.

Conclusions:

• VEGF-mediated arterial morphogenesis depends on the phosphorylation of VEGFR2 at Y1175.
• This phosphorylation requires the trafficking of internalized VEGFR2 away from the plasma membrane via a synectin-myosin-VI complex.
• A novel endosomal trafficking-dependent process regulates this critical step in VEGF signaling.