MLXIPL and obesity due to melanocortin 4 receptor deficiency: Transcription of the genefor carboyhydrate-response-element-binding protein ChREBP, a master regulatorof lipid metabolism, is known to be AMPK-mediated, and we have found thatlevels of this protein are lower in livers of PKA Cβ disrupted mice.Increased fatty acid oxidation and lipolysis, and decreased fatty acid andprotein synthesis through the AMPK pathway may be possible mechanisms by whichPKA Cβ disruption leads to obesity resistance and healthy aging (Figure 2).