IDH3G(异柠檬酸脱氢酶3γ亚基)属于IDH基因家族,该家族编码异柠檬酸脱氢酶(IDH)的关键亚基,参与三羧酸循环(TCA循环)和细胞能量代谢。IDH3G与IDH3A、IDH3B共同组成IDH3异源多聚体,催化异柠檬酸氧化脱羧生成α-酮戊二酸(α-KG),同时还原NAD+为NADH,为线粒体电子传递链提供还原力。IDH3G主要在心脏、骨骼肌等高耗能组织中高表达,其功能依赖于与另外两个亚基的协同作用。IDH3G突变可能导致酶活性丧失,影响能量代谢稳态,但相较于IDH1/2的致癌突变,IDH3G突变较少报道与疾病直接相关。IDH3G表达异常可能通过改变α-KG水平影响表观遗传修饰(如DNA/组蛋白去甲基化),但具体机制尚不明确。IDH基因家族的共性在于催化异柠檬酸脱羧反应,但不同亚型(IDH1/2/3)定位不同:IDH1在胞质,IDH2在线粒体,IDH3则专属性参与TCA循环。IDH3G过表达可能增强TCA循环通量,而低表达可能导致能量代谢障碍,但细胞通常通过其他亚基代偿维持基本功能。目前尚未发现IDH3G与明确遗传病关联,但作为代谢核心酶,其功能变化可能间接影响肿瘤微环境或神经退行性疾病进程。
Isocitrate dehydrogenases catalyze the oxidative decarboxylation of isocitrate to 2-oxoglutarate. These enzymes belong to two distinct subclasses, one of which utilizes NAD(+) as the electron acceptor and the other NADP(+). Five isocitrate dehydrogenases have been reported: three NAD(+)-dependent isocitrate dehydrogenases, which localize to the mitochondrial matrix, and two NADP(+)-dependent isocitrate dehydrogenases, one of which is mitochondrial and the other predominantly cytosolic. NAD(+)-dependent isocitrate dehydrogenases catalyze the allosterically regulated rate-limiting step of the tricarboxylic acid cycle. Each isozyme is a heterotetramer that is composed of two alpha subunits, one beta subunit, and one gamma subunit. The protein encoded by this gene is the gamma subunit of one isozyme of NAD(+)-dependent isocitrate dehydrogenase. This gene is a candidate gene for periventricular heterotopia. Several alternatively spliced transcript variants of this gene have been described, but only some of their full length natures have been determined. [provided by RefSeq, Jul 2008]
异柠檬酸脱氢酶催化异柠檬酸的氧化脱羧到2-酮戊二酸。这些酶属于两个不同的亚类,其中一个利用NAD(+)用作电子受体和其它NADP(+)。五异柠檬酸脱氢酶已经报道:三位NAD(+) - 依赖的异柠檬酸脱氢酶,其定位于线粒体基质,和两个NADP(+) - 依赖的异柠檬酸脱氢酶,其中之一就是线粒体和其他主要胞质。 NAD(+) - 依赖的异柠檬酸脱氢酶催化三羧酸循环的变构调节??的限速步骤。各同工酶是一个,它由两个α亚基,一个β亚基,和一个伽玛亚基异四聚体。由该基因编码的蛋白质是NAD(+)中的一个同工酶的伽马亚基 - 依赖性异柠檬酸脱氢酶。这种基因是脑室周围异位的候选基因。这个基因的几种可变剪接转录物变体已有描述,但只有一些其全长性质的已被确定。 [由RefSeq的,2008年7月提供]
IDH3G基因(以及对应的蛋白质)的细胞分布位置:
IDH3G基因的本体(GO)信息:
名称 |
---|
1200 Carbon metabolism [PATH:hsa01200] |
1210 2-Oxocarboxylic acid metabolism [PATH:hsa01210] |
1230 Biosynthesis of amino acids [PATH:hsa01230] |
20 Citrate cycle (TCA cycle) [PATH:hsa00020] |
名称 |
---|
Citric acid cycle (TCA cycle) |
Metabolism |
Metabolism of proteins |
Mitochondrial protein import |
Pyruvate metabolism and Citric Acid (TCA) cycle |
The citric acid (TCA) cycle and respiratory electron transport |
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