Stalk peptide is a fragment of the N-terminal region of the adhesion G protein-coupled receptor (aGPCR) GPR110, which in common with the general activation mechanism of aGPCRs is generated by an autoproteolysis process, after which it activates the receptor by the tethered stalk peptide mechanism. GPR110, also known as ADGRF1, is an aGPCR that plays a key role in neurite growth and synaptogenesis in cortical neurons, and addition of stalk peptide to a culture of neurons isolated from mouse brain promotes neurite outgrowth similarly to the effect of the endogenous GPR110 ligand docosahexaenoic acid, suggesting that GPR110 is activated through the stalk peptide mechanism under physiological conditions.
