Tetrahydrobiopterin cofactor biosynthesis: GTP cyclohydrolase I mRNA expression in rat brain and superior cervical ganglia.
Tetrahydrobiopterin cofactor biosynthesis: GTP cyclohydrolase I mRNA expression in rat brain and superior cervical ganglia.
复制标题
四氢生物蝶呤辅因子生物合成：大鼠脑和颈上神经节中 GTP 环水解酶 I mRNA 表达。
DOI：
10.1111/j.1471-4159.1993.tb03614.x
复制
发表时间：
1993
影响因子：
4.7
通讯作者：
Kapatos,G
中科院分区：
文献类型：
--
作者：
Hirayama,K;Lentz,SI;Kapatos,G
GTP环水解酶I （GTPCH）是四氢生物蝶呤生物合成中的限速酶，四氢生物蝶呤是儿茶酚胺（CA）、吲哚胺和一氧化氮生物合成所需的还原性蝶呤辅因子。我们利用逆转录-聚合酶链反应技术，基于已发表的大鼠肝脏GTPCH cDNA序列，从大鼠肾上腺mRNA中克隆出一部分GTPCH转录物，并利用该克隆物通过northern blot、核酸酶保护实验和原位杂交分析了大鼠大脑和其他组织中的GTPCH mRNA。northern blot检测到两个长度分别为1.2和3.8 kb的GTPCH mRNA转录本，其中1,2 kb形式在肝脏中占主导地位，3.8 kb形式在培养的松果体、肾上腺、脑干和下丘脑神经元中占主导地位。原位杂交研究将GTPCH mRNA定位到蓝斑、腹侧被盖区和黑质、致密部含CA的核周。通过核酸酶保护实验检测的中央和外周儿茶酚胺神经元GTPCH mRNA水平在单次注射钙消耗药物利血平后24小时增加了两倍；肾上腺中1.2 - kb和3.8 - kb转录本均增加。核酸酶保护实验也在纹状体、海马和小脑以及不含单胺能核周围的大脑区域检测到低水平的GTPCH mRNA。
GTP cyclohydrolase I (GTPCH) is the rate‐limiting enzyme in the biosynthesis of tetrahydrobiopterin, the reduced pteridine cofactor required for catecholamine (CA), indoleamine, and nitric oxide biosynthesis. We have used the reverse transcription‐polymerase chain reaction technique, based on the published cDNA sequence for rat liver GTPCH, to clone a portion of the GTPCH transcript from rat adrenal gland mRNA and have used this clone for the analysis of GTPCH mRNA in brain and other tissues of the rat by northern blot, nuclease protection assay, and in situ hybridisation. Two GTPCH mRNA transcripts of 1.2 and 3.8 kb in length were detected by northern blot, with the 1,2‐kb form predominating in the liver and the 3.8‐kb form in the pineal gland, adrenal gland, brainstem, and hypothalamic neurons maintained in culture. In situ hybridization studies localized GTPCH mRNA to CA‐containing perikarya in the locus ceruleus, ventral tegmental area, and substantia nigra, pars compacta. Levels of GTPCH mRNA in central and peripheral catecholamine neurons determined by nuclease protection assay were increased twofold 24 h after a single injection of the CA‐depleting drug reserpine; both the 1.2‐and 3.8‐kb transcripts were increased in the adrenal gland. Low levels of GTPCH mRNA were also detected by nuclease protection assay in the striatum, hippocampus, and cerebellum, brain regions that do not contain monoaminergic perikarya.