Sci. Signal., 7 August 2012
Molecular Biology The Inner Workings of a Clock
L. Bryan Ray
Science, Science Signaling, AAAS, Washington, DC 20005, USA
Eukaryotic circadian clocks are built at least in part on transcriptional feedback loops, but the mechanisms underlying circadian feedback are poorly understood. Padmanabhan et al. explored the transcriptional feedback mechanism at the heart of the mammalian circadian clock. The proteins PERIOD (PER) and CRYPTOCHROME suppress transcription of their own genes. PER complexes do so in part by recruiting a histone deacetylase to promoters of clock genes. But PER is also present on DNA in a complex with Senataxin, a helicase that functions in transcriptional termination. Senataxin appears to be inhibited in the PER complex, thus inhibiting termination and further reducing the rate of transcription.
K. Padmanabhan, M. S. Robles, T. Westerling, C. J. Weitz, Feedback regulation of transcriptional termination by the mammalian circadian clock PERIOD complex. Science 337, 599–602 (2012). [Abstract] [Full Text]
Citation: L. B. Ray, The Inner Workings of a Clock. Sci. Signal. 5, ec209 (2012).
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