Regulation of Guanosine Triphosphate Cyclohydrolase and Tetrahydrobiopterin Levels and the Role of the Cofactor in Tyrosine Hydroxylation in Primary Cultures of Adrenomedullary Chromaffin Cells
Regulation of Guanosine Triphosphate Cyclohydrolase and Tetrahydrobiopterin Levels and the Role of the Cofactor in Tyrosine Hydroxylation in Primary Cultures of Adrenomedullary Chromaffin Cells
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肾上腺髓质嗜铬细胞原代培养物中三磷酸鸟苷环水解酶和四氢生物蝶呤水平的调节以及辅因子在酪氨酸羟基化中的作用
DOI：
10.1111/j.1471-4159.1986.tb00637.x
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发表时间：
1986
影响因子：
4.7
通讯作者：
O. H. Viveros
中科院分区：
文献类型：
--
作者：
M. Abou;S. Wilson;T. Zimmerman;C. A. Nichol;O. H. Viveros
摘要：选择性地修饰培养嗜铬细胞中四氢生物蝶呤的水平之后，酪氨酸羟化速率发生了变化。Sepiapterin是四氢生物蝶呤合成的挽救途径的中间产物，加入后可迅速增加细胞内四氢生物蝶呤的水平，并提高完整细胞中酪氨酸羟化的速率。当四氢生物蝶呤直接加入到完整细胞的孵育液中时，酪氨酸羟化也被增强。培养的嗜铬细胞经Sepiapterin还原酶抑制剂N-乙酰5-羟色胺处理72h后，四氢生物蝶呤含量和酪氨酸羟化速率均降低。加入Sepiapterin或N-乙酰5-羟色胺对嗜铬细胞总可提取酪氨酸羟基酶活性或儿茶酚胺含量没有一致的影响。用增加环状AMP(Forskolin、霍乱毒素、茶碱、二丁酰基和8-溴环状AMP)水平的化合物处理嗜铬细胞培养3天，可增加总可提取酪氨酸羟基酶活性和GTP-环水解酶，GTP-环水解酶是四氢生物蝶呤生物合成中的限速酶。经8-溴环腺苷处理后，四氢生物蝶呤水平和完整细胞酪氨酸羟化水平显著增加。蛋白质合成抑制剂放线菌酮可阻断8-溴环腺苷诱导的GTP-环水解酶和四氢生物蝶呤的增加。耗竭细胞中儿茶酚胺的药物(利血平、四苯那嗪和溴精)可增加总酪氨酸羟基酶和GTP环水解酶的活性，但利血平或四苯肼处理细胞后，细胞内环磷酸腺苷水平没有变化。Brocresine和Tetbenazine提高了四氢生物蝶呤的水平，但加入利血平则降低了儿茶酚胺和四氢生物蝶呤的含量，并导致完整细胞酪氨酸羟化速率降低，尽管总可提取酶的活性增加。这些数据表明，在培养的嗜铬细胞中，GTP-环水解酶活性与酪氨酸羟化酶活性一样，既受环腺苷依赖机制的调节，也受环AMP非依赖机制的调节，细胞内四氢生物蝶呤的水平是控制酪氨酸羟化速率的众多因素之一。
Abstract: Selective modification of the tetrahydrobiopterin levels in cultured chromaffin cells were followed by changes in the rate of tyrosine hydroxylation. Addition of sepiapterin, an intermediate on the salvage pathway for tetrahydrobiopterin synthesis, rapidly increased intracellular levels of tetrahydrobiopterin and elevated the rate of tyrosine hydroxylation in the intact cell. Tyrosine hydroxylation was also enhanced when tetrahydrobiopterin was directly added to the incubation medium of intact cells. When the cultured chromaffin cells were treated for 72 h with N‐acetylserotonin, an inhibitor of sepiapterin reductase, tetrahydrobiopterin content and the rate of tyrosine hydroxylation were decreased. Addition of sepiapterin or N‐acetylserotonin had no consistent effect on total extractable tyrosine hydroxylase activity or on catecholamine content in the cultured chromaffin cells. Three‐day treatment of chromaffin cell cultures with compounds that increase levels of cyclic AMP (forskolin, cholera toxin, theophylline, dibutyryl‐ and 8‐bromo cyclic AMP) increased total extractable tyrosine hydroxylase activity and GTP‐cyclohydrolase, the rate‐limiting enzyme in the biosynthesis of tetrahydrobiopterin. Tetrahydrobiopterin levels and intact cell tyrosine hydroxylation were markedly increased after 8‐bromo cyclic AMP. The increase in GTP‐cyclohydrolase and tetrahydrobiopterin induced by 8‐bromo cyclic AMP was blocked by the protein synthesis inhibitor cycloheximide. Agents that deplete cellular catecholamines (reserpine, tetrabenazine, and brocresine) increased both total tyrosine hydroxylase and GTP‐cyclohydrolase activities, although treating the cultures with reserpine or tetrabenazine resulted in no change in cellular levels of cyclic AMP. Brocresine and tetrabenazine increased tetrahydrobiopterin levels, but the addition of reserpine to the cultures decreased catecholamine and tetrahydrobiopterin content and resulted in a decreased rate of intact cell tyrosine hydroxylation in spite of the increased activity of the total extractable enzyme. These data indicate that in cultured chromaffin cells GTP‐cyclohydrolase activity like tyrosine hydroxylase activity is regulated by both cyclic AMP‐dependent and cyclic AMP‐independent mechanisms and that the intracellular level of tetrahydrobiopterin is one of the many factors that control the rate of tyrosine hydroxylation.
毒蕈碱可增加大鼠颈上神经节的酪氨酸 3-单加氧酶活性和磷脂代谢。
DOI：
--
发表时间：
1984
期刊：
The Journal of pharmacology and experimental therapeutics
影响因子：
--
作者：
Horwitz,J;Tsymbalov,S;Perlman,RL
通讯作者：
Perlman,RL
环AMP依赖性蛋白激酶不参与断头后肾上腺中酪氨酸羟化酶的体内激活。
DOI：
--
发表时间：
1984
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Tank,AW;Meligeni,J;Weiner,N
通讯作者：
Weiner,N
肾上腺髓质细胞培养物中儿茶酚胺和多巴胺-β-羟化酶的分泌和细胞含量之间的定量相关性。
影响因子：
5.8
作者：
Ledbetter,FH;Kirshner,N
通讯作者：
Kirshner,N