An opioid receptor protein that is a translation product of the human OPRM1 gene or a 1:1 ortholog thereof. The preferred ligands are beta-endorphin and enkephalins. [ PRO:WCB http://en.wikipedia.org/wiki/mu_Opioid_receptor ]

Synonyms: mu opiate receptor M-OR-1 MOR-1 mu opioid receptor mu-opioid receptor OPRM1 MOP