SLC1A5 and obesity due to melanocortin 4 receptor deficiency: Conclusion: Impaired PPAR-γ in obesity provokes downregulation of SLC1A5 and reductions in adipocyte uptake of glutamine and methionine (two epigenetic modulators), leading to disruption of Bmal1. Therefore, PPAR-γ integrates obesity and adipocyte clock, promoting a vicious cycle between circadian disruption and obesity development.