Enables melanocortin receptor activity and peptide hormone binding activity. Involved in several processes, including diet induced thermogenesis; negative regulation of feeding behavior; and regulation of grooming behavior. Located in nucleus and plasma membrane. Used to study obesity. Biomarker of obesity and sciatic neuropathy. Human ortholog(s) of this gene implicated in morbid obesity and obesity. Orthologous to human MC4R (melanocortin 4 receptor). [provided by Alliance of Genome Resources, Apr 2022]