ADCY1 and obesity due to melanocortin 4 receptor deficiency: In fact, it is reported that increased adiposity in an obesity context is the result of a reduction of beta-adrenergic agonist-induced lipolysis, which could be due to both losses of beta-1 and beta-3 adrenoceptor numbers, or to alterations of their coupling to adenylate cyclase through the guanine nucleotide regulatory protein [44].