Alpha-2 adrenergic receptors mediate the catecholamine-induced inhibition of adenylate cyclase through the action of G proteins. The rank order of potency for agonists of this receptor is oxymetazoline > clonidine > epinephrine > norepinephrine > phenylephrine > dopamine > p-synephrine > p-tyramine > serotonin = p-octopamine. For antagonists, the rank order is yohimbine > phentolamine = mianserine > chlorpromazine = spiperone = prazosin > propanolol > alprenolol = pindolol. Belongs to the G-protein coupled receptor 1 family. Adrenergic receptor subfamily. ADRA2A sub-subfamily. It is uncertain whether Met-1 or Met-16 is the initiator. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus. Truncated N-terminus.