CaMKII is essential for the cellular clock and coupling between morning and evening behavioral rhythms
- Naohiro Kon1,
- Tomoko Yoshikawa2,
- Sato Honma2,
- Yoko Yamagata3,4,
- Hikari Yoshitane1,
- Kimiko Shimizu1,
- Yasunori Sugiyama1,
- Chihiro Hara1,
- Isamu Kameshita5,
- Ken-ichi Honma2 and
- Yoshitaka Fukada1,6
- 1Department of Biosciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan;
- 2Department of Chronomedicine, Center for Cooperative Projects, Hokkaido University Graduate School of Medicine, Sapporo 060-8638, Japan;
- 3Department of Information Physiology, National Institute for Physiological Sciences,
- 4The Graduate University for Advanced Studies (SOKENDAI), Okazaki 444-8787, Japan;
- 5Department of Life Sciences, Faculty of Agriculture, Kagawa University, Miki-cho, Kagawa 761-0795, Japan
Abstract
Daily behavioral rhythms in mammals are governed by the central circadian clock, located in the suprachiasmatic nucleus (SCN). The behavioral rhythms persist even in constant darkness, with a stable activity time due to coupling between two oscillators that determine the morning and evening activities. Accumulating evidence supports a prerequisite role for Ca2+ in the robust oscillation of the SCN, yet the underlying molecular mechanism remains elusive. Here, we show that Ca2+/calmodulin-dependent protein kinase II (CaMKII) activity is essential for not only the cellular oscillation but also synchronization among oscillators in the SCN. A kinase-dead mutation in mouse CaMKIIα weakened the behavioral rhythmicity and elicited decoupling between the morning and evening activity rhythms, sometimes causing arrhythmicity. In the mutant SCN, the right and left nuclei showed uncoupled oscillations. Cellular and biochemical analyses revealed that Ca2+–calmodulin–CaMKII signaling contributes to activation of E-box-dependent gene expression through promoting dimerization of circadian locomotor output cycles kaput (CLOCK) and brain and muscle Arnt-like protein 1 (BMAL1). These results demonstrate a dual role of CaMKII as a component of cell-autonomous clockwork and as a synchronizer integrating circadian behavioral activities.
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Footnotes
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↵6 Corresponding author
E-mail sfukada{at}mail.ecc.u-tokyo.ac.jp
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Supplemental material is available for this article.
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Article is online at http://www.genesdev.org/cgi/doi/10.1101/gad.237511.114.
- Received January 3, 2014.
- Accepted April 16, 2014.
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