Enables melanocyte-stimulating hormone receptor activity. Involved in intracellular signal transduction; positive regulation of intracellular signal transduction; and positive regulation of transcription by RNA polymerase II. Acts upstream of or within melanin biosynthetic process; pigmentation; and sensory perception of pain. Predicted to be located in membrane. Predicted to be integral component of membrane. Predicted to be active in cytoplasm and plasma membrane. Is expressed in ductus deferens; epididymis; esophagus; and skin. Human ortholog(s) of this gene implicated in familial melanoma; major depressive disorder; melanoma; oculocutaneous albinism type II; and pigmentation disease. Orthologous to human MC1R (melanocortin 1 receptor). [provided by Alliance of Genome Resources, Nov 2021]