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Please use this identifier to cite or link to this item: http://arks.princeton.edu/ark:/88435/dsp011c18dj90w
Title: STRUCTURE AND MECHANISM OF NOCTURNIN AND NADK2: THE DISCOVERY OF A MOLECULAR LINK BETWEEN THE CIRCADIAN CLOCK AND METABOLISM
Authors: Du, Jin
Advisors: Korennykh, Alexei V
Contributors: Molecular Biology Department
Keywords: NAD kinase 2
NADP(H)
Nocturnin
Subjects: Biochemistry
Issue Date: 2021
Publisher: Princeton, NJ : Princeton University
Abstract: Nicotinamide dinucleotides NADP(H) and NAD(H) are central cofactors driving metabolic reactions in all forms of life. The cellular roles of both NADP(H) and NAD(H) are remarkably well-understood. Nevertheless, here I describe the discovery that the circadian protein Nocturnin belongs to a new enzyme class, which converts NADP(H) into NAD(H) inside mitochondria. I also describe the use of X-ray crystallography, biochemistry, metabolomics and cell biology to decipher mechanisms of 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, our lab showed that purified NOCT lacks the deadenylase activity. We solved the apo structure of NOCT and showed that NOCT is not compatible with RNA cleavage through structural and conservation analysis with canonical deadenylases. We further performed an unbiased metabolomics screen and found that NOCT specifically and directly converts the dinucleotide NADP+ into NAD+, and NADPH into NADH. Our co-crystal structure of NOCT bound to NADPH explained the specific substrate-enzyme interaction. Confocal analysis showed that NOCT is targeted to mitochondria. NADP(H) regulation, which takes place at least in part in mitochondria, establishes the molecular link between circadian clock and metabolism.
URI: http://arks.princeton.edu/ark:/88435/dsp011c18dj90w
Alternate format: The Mudd Manuscript Library retains one bound copy of each dissertation. Search for these copies in the library's main catalog: catalog.princeton.edu
Type of Material: Academic dissertations (Ph.D.)
Language: en
Appears in Collections:Molecular Biology

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