CNR1 and obesity due to melanocortin 4 receptor deficiency: Since ERK-p is in turn involved in the activation of SREBP by phosphorylation [37], [52], [53] these observations reflect a contradictory signal triggered in PrAT of animals exposed to diet-induced obesity for a long time; i.e., suppression and activation of lipogenic gene expression simultaneously, with the ERK-p status being CB1 dependent.