Fig. 6.
Model of the interactions of PKA–RIIβ with agouti. In the absence of the predominant neuronal regulatory subunit RIIβ, it is proposed that there is unregulated PKA activity and an increase in type I kinase in key hypothalamic neurons that are also expressing MC4R. The result is an overall increase in PKA signaling downstream of the melanocortin receptors resulting in decreased feeding and increased energy expenditure in Ay/RIIβ KO mice. Immunohistochemistry detection of RIIβ expression in the hypothalamic areas of the PVH and surrounding structures is shown in green with DNA counterstained in blue (To-Pro-3).