Abstract
The circadian clock is a biological system ubiquitous to almost all organisms on the earth, and controls daily rhythms in our body. Many physiological functions are rhythmically regulated by the cycles of expression, post-translational modification, and degradation of the clock proteins constituting the circadian clock. Disruption of circadian rhythms due to shift work and social jet lag is getting worse in modern society, and has been related with not only sleep disorders, but also various diseases, such as cancer and metabolic disorders. Small-molecule compounds targeting the clock-related proteins will provide a useful tool for uncovering the molecular mechanisms of circadian-related diseases and their treatments. In this article, we introduce the unique circadian clock modulating compounds and their potential for drug discovery.