Dimerization drives EGFR endocytosis through two sets of compatible endocytic codes

Area of Science:

• Cell biology
• Molecular signaling
• Receptor trafficking

Background:

• Epidermal growth factor receptor (EGFR) endocytosis is crucial for signal regulation.
• EGFR dimerization is known to control its endocytosis, but the mechanism remains unclear.

Purpose of the Study:

• To investigate how EGFR dimerization drives receptor internalization.
• To test the hypothesis that dimerization brings two sets of endocytic codes into proximity.

Main Methods:

• Generating specific homo- and hetero-dimers of various receptors and their mutants.
• Analyzing the endocytosis efficiency of these receptor dimers.

Main Results:

• ErbB2 and ErbB3 homodimers are deficient in endocytosis due to a lack of endocytic codes.
• EGFR-ErbB2, EGFR-ErbB3, and EGFR-EGFRΔ1005-1017 heterodimers show impaired endocytosis.
• EGFR-PDGFRβ heterodimers are endocytosis deficient, unlike their competent homodimers, indicating a need for compatible codes.
• Spatial coordination of compatible endocytic codes is necessary for receptor dimer endocytosis.

Conclusions:

• Two sets of compatible endocytic codes are essential for receptor endocytosis.
• These codes must be spatially coordinated within the receptor dimer for internalization to occur.