Exocytosis of Insulin 'G-protein alpha i/o:GTP Complex [plasma membrane]' negatively regulates 'Exocytosis of Insulin' INHIBITION Pubmed12684222 Pubmed14514350 Pubmed17900700 Pubmed18162464 Pubmed7641683 Pubmed8997178 Reactome Database ID Release 43422251 Reactome, http://www.reactome.org ReactomeREACT_19097 The major effect of adrenaline and noradrenaline on insulin secretion is the inhibition of exocytosis of pre-existing insulin secretory granules. The inhibition occurs at a "distal site", that is, the effect is most pronounced on granules already near the cytosolic face of the plasma membrane. The effect is caused by the Gi/o alpha:GTP complex but the exact mechanism by which Gi/o alpha:GTP inhibits exocytosis is unknown. G-protein alpha i/o:GTP Complex