KCNJ3(钾电压门控通道亚家族J成员3)属于内向整流钾通道(Kir)基因家族,该家族以调控细胞膜电位和维持钾离子平衡为共同特征。KCNJ3编码Kir3.1蛋白,与Kir3.2/3/4亚基共同形成G蛋白偶联内向整流钾通道(GIRK),在心脏、神经系统和内分泌组织中广泛表达。其核心功能是通过响应G蛋白信号(如乙酰胆碱或腺苷)开放通道,促使钾离子外流,导致细胞超极化,从而抑制神经元兴奋性或减缓心率。在心脏中,GIRK通道介导迷走神经对窦房结的调控,突变可能引发心律失常(如心房颤动)。神经系统中的KCNJ3通过抑制多巴胺能神经元活动影响奖赏回路,与成瘾行为相关;其功能异常还被关联到癫痫和精神分裂症。若KCNJ3过表达,可能导致细胞过度抑制(如心动过缓或认知障碍),而表达降低则可能引发神经元过度兴奋(癫痫倾向)或心脏自律性异常。该基因的突变可破坏通道组装或G蛋白敏感性,例如R67H突变会减少膜定位,导致通道功能丧失。Kir家族成员均含两个跨膜结构域和高度保守的P环选择性滤器,但各亚型具有组织特异性调控机制。KCNJ3还与KCNJ5/KCNJ9等形成异源四聚体,扩展其功能多样性,例如在肾上腺中与KCNJ5组合调控醛固酮分泌。研究提示KCNJ3可能成为心律失常或神经精神疾病的潜在治疗靶点,其调节剂如Tertiapin-Q(蜂毒衍生肽)可特异性阻断GIRK1/4通道活性。
Potassium channels are present in most mammalian cells, where they participate in a wide range of physiologic responses. The protein encoded by this gene is an integral membrane protein and inward-rectifier type potassium channel. The encoded protein, which has a greater tendency to allow potassium to flow into a cell rather than out of a cell, is controlled by G-proteins and plays an important role in regulating heartbeat. It associates with three other G-protein-activated potassium channels to form a heteromultimeric pore-forming complex that also couples to neurotransmitter receptors in the brain and whereby channel activation can inhibit action potential firing by hyperpolarizing the plasma membrane. These multimeric G-protein-gated inwardly-rectifying potassium (GIRK) channels may play a role in the pathophysiology of epilepsy, addiction, Down's syndrome, ataxia, and Parkinson's disease. Alternative splicing results in multiple transcript variants encoding distinct proteins. [provided by RefSeq, May 2012]
钾通道存在于大多数哺乳动物细胞,在那里他们参与广泛的生理反应。由该基因编码的蛋白质是一种完整的膜蛋白和向内整流型钾通道。所编码的蛋白质,其具有更大的趋势,以允许钾流入细胞而不是出于细胞的,是由G蛋白控制的和在调节心跳中起重要作用。它与其他三个G蛋白活化的钾通道相关联,以形成异源多孔隙形成复合物,也耦合到神经递质在脑和由此通道活化受体可以通过超极化质膜抑制动作电位发放。这些多聚G蛋白 - 门控向内整流钾(GIRK)信道可以在癫痫症,成瘾,唐氏综合征,共济失调,和帕金森氏病的病理生理学中发挥作用。在多个转录剪接变异体导致编码不同的蛋白质。 [由RefSeq的,2012年5月提供]
KCNJ3基因(以及对应的蛋白质)的细胞分布位置:
KCNJ3基因的本体(GO)信息:
名称 |
---|
4915 Estrogen signaling pathway [PATH:hsa04915] |
4921 Oxytocin signaling pathway [PATH:hsa04921] |
4724 Glutamatergic synapse [PATH:hsa04724] |
4725 Cholinergic synapse [PATH:hsa04725] |
4728 Dopaminergic synapse [PATH:hsa04728] |
4726 Serotonergic synapse [PATH:hsa04726] |
4723 Retrograde endocannabinoid signaling [PATH:hsa04723] |
4713 Circadian entrainment [PATH:hsa04713] |
5032 Morphine addiction [PATH:hsa05032] |
名称 |
---|
Activation of G protein gated Potassium channels |
Activation of GABAB receptors |
G protein gated Potassium channels |
GABA B receptor activation |
GABA receptor activation |
Inhibition of voltage gated Ca2+ channels via Gbeta/gamma subunits |
Inwardly rectifying K+ channels |
Neuronal System |
Neurotransmitter Receptor Binding And Downstream Transmission In The Postsynaptic Cell |
Potassium Channels |
Transmission across Chemical Synapses |
疾病名称 | 关系值 | NofPmids | NofSnps | 来源 |
Glycogen Storage Disease Type IV | 0.00272435 | 1 | 0 | LHGDN |
Lung Neoplasms | 0.00272435 | 1 | 0 | LHGDN |
Epilepsy | 0.002638474 | 2 | 0 | BeFree_GAD |
Breast Carcinoma | 0.000542884 | 2 | 0 | BeFree |
Secondary malignant neoplasm of lymph node | 0.000542884 | 2 | 0 | BeFree |
Glioma | 0.000271442 | 1 | 0 | BeFree |
Non-Small Cell Lung Carcinoma | 0.000271442 | 1 | 0 | BeFree |
Maturity onset diabetes mellitus in young | 0.000271442 | 1 | 0 | BeFree |
Mammary Neoplasms | 0.000271442 | 1 | 0 | BeFree |
Adenocarcinoma | 0.000271442 | 1 | 0 | BeFree |
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