Craft C M, Murage J, Brown B, Zhan-Poe X
Mary D. Allen Laboratory for Vision Research, Doheny Eye Institute, Department of Cell and Neurobiology, University of Southern California School of Medicine, 1333 San Pablo Street, BMT 401, Los Angeles, CA 90033, USA.
Brain Res Mol Brain Res. 1999 Feb 19;65(1):44-51. doi: 10.1016/s0169-328x(98)00336-2.
Arylalkylamine N-acetyltransferase (AA-NAT, E. C. 2.3.1.87) is the enzyme that catalyzes the transfer of an acetyl group from acetyl-CoA to serotonin to form N-acetylserotonin (NAS) in the indoleamine biosynthetic pathway. Bovine pineal AA-NAT, partially purified on an anion exchange column, displayed an 8-fold higher enzymatic activity in pineals from animals killed in early morning (0800) compared to an afternoon group (1430). Poly A(+) mRNA was isolated from early morning bovine pineals, used to construct a mammalian expression cDNA library (lambdaZAP Express), and then screened with a rat AA-NAT cDNA to isolate a 924 basepair cDNA that encodes the bovine pineal AA-NAT. The amino acid sequence alignment reveals that bovine AA-NAT shares 94.20%, 78.54%, 76.33% and 56.3% identity to ovine, rat, human and chicken sequences, respectively. Northern blot analysis demonstrates a 0.7-fold higher mRNA level in pineal glands taken from animals from the 0800 time-point compared with mRNA from the 1430 time-point. AA-NAT mRNA was expressed at high levels in pineal and retina, but the message was undetectable in adrenal, cerebellum, cortex, small intestine, testis and thyroid. Based on the significant identity of amino acid sequence and the similar mRNA expression pattern, these data suggest that the bovine AA-NAT is more analogous to the ovine rather than either the rat, human or chicken AA-NAT.
芳基烷基胺N - 乙酰基转移酶（AA - NAT，E.C. 2.3.1.87）是一种在吲哚胺生物合成途径中催化乙酰辅酶A的乙酰基转移至血清素以形成N - 乙酰血清素（NAS）的酶。在阴离子交换柱上部分纯化的牛松果体AA - NAT，与下午组（14:30）相比，在清晨（08:00）处死的动物的松果体中显示出高8倍的酶活性。从清晨牛松果体中分离出Poly A(+) mRNA，用于构建哺乳动物表达cDNA文库（lambdaZAP Express），然后用大鼠AA - NAT cDNA进行筛选，以分离出编码牛松果体AA - NAT的924个碱基对的cDNA。氨基酸序列比对显示，牛AA - NAT与绵羊、大鼠、人类和鸡的序列分别具有94.20%、78.54%、76.33%和56.3%的同一性。Northern印迹分析表明，与14:30时间点的mRNA相比，取自08:00时间点动物的松果体中mRNA水平高0.7倍。AA - NAT mRNA在松果体和视网膜中高水平表达，但在肾上腺、小脑、皮质、小肠、睾丸和甲状腺中未检测到该信息。基于氨基酸序列的显著同一性和相似的mRNA表达模式，这些数据表明牛AA - NAT与绵羊的AA - NAT比与大鼠、人类或鸡的AA - NAT更相似。
