The metabolites NADP+ and NADPH are the targets of the circadian protein Nocturnin (Curled)
The metabolites NADP+ and NADPH are the targets of the circadian protein Nocturnin (Curled)
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DOI：
10.1038/s41467-019-10125-z
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发表时间：
2019-05-30
影响因子：
16.6
通讯作者：
Korennykh, Alexei
中科院分区：
文献类型：
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作者：
Estrella, Michael A.;Du, Jin;Korennykh, Alexei
Nocturnin（NOCT）是一种在生物钟控制下有节律性表达的蛋白质，调节代谢。已经提出NOCT去腺苷化并调节代谢酶mRNA。然而，与其他去腺苷酸酶相比，纯化的NOCT缺乏去腺苷酸酶活性。为了鉴定NOCT的底物，我们进行了质谱筛选，并报告NOCT特异性地直接将二核苷酸NADP（+）转化为NAD（+），并将NADPH转化为NADH。此外，我们证明，果蝇NOCT直系同源物，卷曲，具有相同的酶活性。我们获得了人NOCT.NADPH复合物的2.7埃晶体结构，这表明NOCT识别代谢物的化学上独特的核糖磷酸骨架，有效地将2 '-末端磷酸盐置于去除位置。我们提供了NOCT靶向线粒体的证据，并提出NADP（H）调节，至少部分发生在线粒体中，建立了生物钟和代谢之间的分子联系。
Nocturnin (NOCT) is a rhythmically expressed protein that regulates metabolism under the control of circadian clock. It has been proposed that NOCT deadenylates and regulates metabolic enzyme mRNAs. However, in contrast to other deadenylases, purified NOCT lacks the deadenylase activity. To identify the substrate of NOCT, we conducted a mass spectrometry screen and report that NOCT specifically and directly converts the dinucleotide NADP(+) into NAD(+) and NADPH into NADH. Further, we demonstrate that the Drosophila NOCT ortholog, Curled, has the same enzymatic activity. We obtained the 2.7 angstrom crystal structure of the human NOCT.NADPH complex, which revealed that NOCT recognizes the chemically unique ribose-phosphate backbone of the metabolite, placing the 2'-terminal phosphate productively for removal. We provide evidence for NOCT targeting to mitochondria and propose that NADP(H) regulation, which takes place at least in part in mitochondria, establishes the molecular link between circadian clock and metabolism.