SLC29A4 Q7RTT9

平衡型核苷转运蛋白 4 (hENT4) (质膜单胺转运蛋白) (PMAT) (溶质载体家族 29 成员 4)

功能描述

生电性电压依赖性转运蛋白，介导多种内源性生物活性胺、阳离子异源物质和药物的转运 (PubMed:15448143, PubMed:16099839, PubMed:16873718, PubMed:17018840, PubMed:17121826, PubMed:20592246, PubMed:20858707, PubMed:22396231, PubMed:31537831)。利用生理性的膜内负电位作为驱动力，促进细胞对有机阳离子的摄取 (PubMed:15448143, PubMed:20592246, PubMed:22396231)。作为不依赖 Na(+) 和 Cl(-) 的双向转运蛋白发挥作用 (PubMed:15448143, PubMed:16099839, PubMed:22396231, PubMed:31537831)。底物转运具有 pH 依赖性，并在酸性条件下增强，这很可能是转运蛋白结构发生变构变化的结果 (PubMed:16873718, PubMed:17018840, PubMed:20592246, PubMed:22396231, PubMed:31537831)。参与单胺类神经递质的摄取，如血清素、多巴胺、肾上腺素、去甲肾上腺素、组胺和酪胺，从而支持在中枢神经系统中胺能神经传递的稳态调节作用 (PubMed:15448143, PubMed:16099839, PubMed:17018840, PubMed:17121826, PubMed:20858707, PubMed:22396231)。还负责通过血-脑脊液 (CSF) 屏障摄取生物活性胺和药物，从脑脊液进入脉络丛上皮细胞，从而在清除脑内阳离子神经毒素、异源物质和代谢废物方面发挥重要作用 (By similarity)。参与嘌呤核苷腺苷的双向转运，并在调节心脏组织（特别是在缺血期间）细胞外腺苷浓度方面发挥作用 (PubMed:16873718, PubMed:20592246, PubMed:31537831)。可能参与从肾小管腔摄取有机阳离子进入肾小管细胞，从而有助于肾脏中有机阳离子的重吸收 (PubMed:17018840)。也转运胍基丁胺 (PubMed:16099839)。 {ECO:0000250|UniProtKB:Q8R139, ECO:0000269|PubMed:15448143, ECO:0000269|PubMed:16099839, ECO:0000269|PubMed:16873718, ECO:0000269|PubMed:17018840, ECO:0000269|PubMed:17121826, ECO:0000269|PubMed:20592246, ECO:0000269|PubMed:20858707, ECO:0000269|PubMed:22396231, ECO:0000269|PubMed:31537831}。

组织特异性

Mainly expressed in brain and skeletal muscle (PubMed:15448143, PubMed:16873718, PubMed:20592246, PubMed:20858707). In brain, expressed in cerebellum, cerebral cortex, medulla oblongata, occipital pole, frontal and temporal lobes putamen, spinal cord, substancia nigra, hippocampus, caudate nucleus, nucleus accumbens, pons and choroid plexus (PubMed:15448143, PubMed:16873718, PubMed:20858707, PubMed:23255610). Expressed in heart, in both cardiomyocytes and vascular endothelial cells (PubMed:15448143, PubMed:16873718, PubMed:20858707). Also expressed in adrenal gland, small intestine, pancreas, kidney, liver, bone marrow, lymph node (PubMed:15448143, PubMed:16873718, PubMed:17018840, PubMed:20858707). Located in endometrial stroma, where the expression is high in the proliferative phase, decreases during the secretory phase, and is no longer detectable in the menstrual phase (PubMed:17393420).

亚细胞定位

Cell membrane