We immunoprecipitated spinophilin from pancreatic lysates and immunoblotted for interacting proteins observed in our initial proteomics study, including neurabin, PP1α, and myosin-9 in control mice and two different models of glucose intolerance, Ins2Akita mice, which develop insulin resistance but not obesity, and Leprdb/db mice that are both obese and insulin resistant. This evidence concerns the gene PPP1CA and obesity due to melanocortin 4 receptor deficiency.