Melanocortin 5 receptor (MC<sub>5</sub>R) is a protein that in humans is encoded by the gene. It is located on the chromosome 18 in the human genome. When the MC<sub>5</sub>R was disrupted in transgenic mice, it induced disruption of their exocrine glands and resulted in decreased production of sebum.
MC<sub>5</sub>R is necessary for normal sebum production. Stimulation of MC<sub>5</sub>R promotes fatty acid oxidation in skeletal muscle and lipolysis in adipocytes. MC<sub>5</sub>R is essential for erythrocyte differentiation. MC<sub>5</sub>R is involved in inflammation. MC<sub>5</sub>R helps maintain thermal homeostasis. Stimulation of the MC5R in skeletal muscle causes glucose uptake. In vitro, MC5R agonism is cardioprotective and kidney protective.
MC<sub>5</sub>R is expressed in the brain at different levels depending on physical activity.
MC<sub>5</sub>R is heavily expressed in the preputial gland in mice (a modified sebaceous gland involved in pheromone production). MC<sub>5</sub>R deficiency in male mice decreases aggressive behavior, promotes defensive behavior and encourages other male mice to attack MC<sub>5</sub>R-deficient males through pheromonal signals.
Melanocortin 2 receptor accessory protein (MRAP) traps MC<sub>5</sub>R protein inside cells.
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