6CM4181313489ENSG00000149295ENSMUSG00000032259P14416P61168NM_016574、NM_000795、XM_017017296NM_010077、XM_006509996NP_000786、NP_057658、XP_016872785NP_000786.1NP_034207、XP_006510059多巴胺受体D2（Dopamine receptor D2，简称D2R），为翻译自 DRD2 基因的一种多巴胺受体蛋白。D2R最早于1975年为Philip Seeman（英语：Philip Seeman）所发现，并将其命名为“抗精神疾患性多巴胺受体”（antipsychotic dopamine receptor）。D2R为所有抗精神病药物的作用标的。D2R属于一种多巴胺受体（英语：dopamine receptor），并会与Gi结合。Gi为G蛋白偶联受体的一种亚型，会抑制腺苷酸环化酶的活性。在小鼠模式中，齿状回（英语：dentate gyrus）的neuronal calcium sensor-1（英语：neuronal calcium sensor-1）（NCS-1）会影响D2R在细胞膜的表现量。这项机制会影响突触可塑性及记忆形成。在苍蝇模式中，多巴胺性神经元上的D2R自体受器（英语：autoreceptor）能避免神经元死亡，进而引发类帕金森病的症状。Alternative splicing of this gene results in three transcript variants encoding different isoform（英语：isoform）s.The long form (D2Lh) has the "canonical" sequence and functions as a classic post-synaptic receptor.The short form (D2Sh) is pre-synaptic and functions as an autoreceptor（英语：autoreceptor） that regulates the levels of dopamine in the synaptic cleft.Agonism of D2sh receptors inhibits dopamine release; antagonism increases dopaminergic（英语：dopaminergic） release.A third D2(Longer) form differs from the canonical sequence where 270V is replaced by VVQ.等位基因变异：Some researchers have previously associated the polymorphism Taq 1A (rs1800497) to the DRD2 gene. However, the polymorphism resides in exon 8 of the ANKK1（英语：ANKK1） gene.DRD2 TaqIA polymorphism has been reported to be associated with an increased risk for developing motor fluctuations but not hallucinations in Parkinson's disease.Most of the older antipsychotic drugs such as chlorpromazine and haloperidol are antagonists for the dopamine D2 receptor, but are, in general, very unselective, at best selective only for the "D2-like family" receptors and so binding to D2, D3 and D4, and often also to many other receptors such as those for serotonin and histamine, resulting in a range of side-effects and making them poor agents for scientific research. In similar manner, older dopamine agonists used for Parkinson's disease such as bromocriptine and cabergoline（英语：cabergoline） are poorly selective for one dopamine receptor over another, and, although most of these agents do act as D2 agonists, they affect other subtypes as well. Several selective D2 ligands are, however, now available, and this number is likely to increase as further research progresses.The dopamine receptor D2 has been shown to interact with EPB41L1（英语：EPB41L1）,PPP1R9B（英语：PPP1R9B）and NCS-1（英语：NCS-1）.The D2 receptor forms receptor heterodimers（英语：GPCR oligomer） in vivo (in living animals) with other G protein-coupled receptors; these include:The D2 receptor has been shown to form hetorodimers in vitro (and possibly in vivo) with DRD3（英语：Dopamine D3 receptor）,DRD5（英语：Dopamine receptor D5）,and 5-HT2A（英语：5-HT2A receptor）.多巴胺受体D2引用了美国国家医学图书馆提供的数据，这些数据属于公共领域。Template:Dopaminergics