Circadian oscillations of NADH redox state using a heterologous metabolic sensor in mammalian cells

Guocun Huang, Yunfeng Zhang, Yongli Shan, Shuzhang Yang, Yogarany Chelliah, Han Wang, Joseph S. Takahashi

Research output: Contribution to journalArticlepeer-review

8 Scopus citations


It is known that there are mechanistic links between circadian clocks and metabolic cycles. Reduced nicotinamide adenine dinucleotide (NADH) is a key metabolic cofactor in all living cells; however, it is not known whether levels of NADH oscillate or not. Here we employed REX, a bacterial NADH-binding protein, fused to the VP16 activator to convert intracellular endogenous redox balance into transcriptional readouts by a reporter gene in mammalian cells. EMSA results show that the DNA binding activity of both T- and S-REX::VP16 fusions is decreased with a reduced-to-oxidized cofactor ratio increase. Transient and stabilized cell lines bearing the REX::VP16 and the REX binding operator (ROP) exhibit two circadian luminescence cycles. Consistent with these results, NADH oscillations are observed in host cells, indicating REX can act as a NADH sensor to report intracellular dynamic redox homeostasis in mammalian cells in real time. NADH oscillations provide another metabolic signal for coupling the circadian clock and cellular metabolic states.

Original languageEnglish (US)
Pages (from-to)23906-23914
Number of pages9
JournalJournal of Biological Chemistry
Issue number46
StatePublished - Nov 11 2016

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'Circadian oscillations of NADH redox state using a heterologous metabolic sensor in mammalian cells'. Together they form a unique fingerprint.

Cite this