FIGURE 1.

G‐protein signalling pathway. Schematic showing the canonical stimulatory G‐protein (G_s) pathway for melanocortin 4‐receptor (MC4R) signalling and gene expression. Binding of α‐melanocyte‐stimulating hormone (MSH) to the MC4R causes the activation of the G‐protein, with αßγ‐subunits dissociating into α‐/ßγ‐subunits. The dissociated Gα_s causes the activation of adenylyl cyclase (AC), leading to the conversion of ATP to cyclic adenosine monophosphate (cAMP). cAMP activates inactive protein kinase A (PKA) which is translocated into the nucleus, activating the transcription factor cAMP response element binding protein (CREB) via phosphorylation of CREB, which regulates transcription. GTP, guanosine triphosphate