Figure 6.

Transactivation of the EGFR by FSH. Many lines of evidence point to EGFR transactivation as an important transduction mechanism used by FSHR. Two mechanisms have been reported: first, FSH stimulates the ADAM17 metalloprotease that leads to the release of an EGF-like ligand, which subsequently binds to and activates EGFR; second, FSH activates Src which directly phosphorylates EGFR, thereby eliciting EGF-independent activation of this receptor. MAPK ERK and PI3K pathways have been shown to be activated as a result of EGFR transactivation by FSHR.