ErbB proteins play a significant role in the pathogenesis of a wide variety of human tumors. The significance of ErbB1, also known as epidermal growth factor receptor (EGFR), and ErbB2 is widely accepted, but much less is known about ErbB3.

ErbB3 is a receptor for heregulin, a large family of peptide growth factors. Although it is a receptor tyrosine kinase from a structural point of view, it lacks a functional kinase activity. Therefore, it must form heteroclusters with other ErbB proteins, preferentially ErbB2, to induce transmembrane signaling.

The associations of ErbB3 are important since they lead to the activation of the phosphatidylinositol 3-kinase (PI3K) pathway which worsens the prognosis of tumors.

I am currently in the preliminary stages of investigating the clustering of ErbB3.

I would like to decipher the quantitative aspects of these associations, especially

- what kind of homoclusters ErbB3 form in quiescent and stimulated cells

- how these homoclusters are influenced by coexpression of ErbB2