Engineering EGFR ligands sensors and binders for assessment of autocrine signaling and cell communication in vivo
The ErbB family of receptors are fundamental drivers of many cellular processes. Often playing a major role in developmental biology and pathologic conditions such as cancers, a lot of research has gone into the development of therapeutics to alter the signaling via this receptor family. Signaling by the ErbB receptors requires receptor dimerization induced by ligand binding. This family contains 12 ligands with unique binding properties to the receptors as well as differential signaling and phenotypic outcome. These ligands exist as pro-forms on the cell surface and are released by proteases for autocrine/paracrine activation.
Presently, the only existing methods for analyzing ErbB ligand autocrine loops are destructive, do not permit spatial resolution, high temporal resolution nor live-cell measurements. In this project I seek to develop sensors for the quantitative analysis of the ErbB autocrine loop with high spatial and temporal resolution. To reach this goal, I harness the power of yeast surface display to obtain ErbB ligand binders based on the human 10th fibronectin 3 (FN3) domain conjugated with the high sensitivity of environment sensitive fluorescent probes. I hypothesize that this new technology will provide the temporal and spatial resolution necessary to study the EGFR family autocrine and paracrine loops in vitro and in vivo and allow a better understanding of the extracellular signaling network.