Dissection of Mammalian Biological Clock System at a Molecular Level

Outline of Final Research Achievements

Most living organisms show a variety of rhythms by virtue of having an intrinsic time-measuring system. This system is called circadian clock entrainable to daily changes in the internal and environmental conditions such as light-dark cycle. In mammals, the central clock resides in the hypothalamic suprachismatic nucleus (SCN), and its output signal play significant roles in maintenance of brain functions. This research project aimed to understand the molecular mechanisms underlying the circadian clock oscillation together with its input and output regulation. The major outcomes follow: 1) We identified several key molecules in the input pathway. 2) We found that the SCN clock governs brain peripheral clocks that regulate long-term memory formation and anxiety-like behaviors via SCOP, and 3) we found essential roles of new clock components such as FBXL3/21 and ADAR2 that are important for post-translational and post-transcriptional regulation.