OPRM1 : opioid receptor mu 1
Description
The OPRM1 (opioid receptor mu 1) is a protein-coding gene located on chromosome 6.
The OPRM1 gene provides instructions for making a protein called the mu (μ) opioid receptor. Opioid receptors are part of the endogenous opioid system, which is the body's internal system for regulating pain, reward, and addictive behaviors. It consists of opioid substances produced naturally within the body (called endogenous opioids) and their receptors, into which opioids fit like keys into locks. Opioid receptors are found in the nervous system, where they are embedded in the outer membrane of nerve cells (neurons). When opioids attach (bind) to the receptors, the interaction triggers a series of chemical changes within and between neurons that lead to feelings of pleasure and pain relief.The μ opioid receptor was the first opioid receptor to be discovered. It is the primary receptor for endogenous opioids called beta-endorphin and enkephalins, which help regulate the body's response to pain, among other functions. The μ opioid receptor is also the binding site for many opioids introduced from outside the body (called exogenous opioids). These include commonly prescribed pain medications such as oxycodone, fentanyl, buprenorphine, methadone, oxymorphone, hydrocodone, codeine, and morphine, as well as illegal opioid drugs such as heroin.When endogenous or exogenous opioids bind to the μ opioid receptor, the interaction triggers a cascade of chemical signals in the nervous system. These signals reduce the activity (excitability) of neurons in certain areas of the brain, which leads to pain relief and feelings of pleasure and intense happiness (euphoria). In addition, the chemical signaling ultimately increases the production of a chemical called dopamine. Dopamine is a chemical messenger (neurotransmitter) that helps regulate areas of the brain involved in reward-seeking behavior, attention, and mood.
The OPRM1 gene encodes a receptor protein that binds to various endogenous and exogenous opioid ligands, including beta-endorphin, endomorphin, morphine, heroin, DAMGO, fentanyl, etorphine, buprenorphin, and methadone. The receptor interacts with G proteins, primarily G(i) and G(o), leading to downstream signaling events that modulate cellular processes such as inhibition of adenylate cyclase activity, regulation of calcium channels, activation of potassium channels, and activation of various signaling pathways. The receptor also undergoes desensitization, endocytosis, and recycling, processes regulated by phosphorylation and interaction with beta-arrestins. It can interact with other GPCRs to form heterooligomers, modulating its binding, signaling, and trafficking properties.
OPRM1 is also known as LMOR, M-OR-1, MOP, MOR, MOR1, OPRM.
