Animal clocks: a multitude of molecular mechanisms for circadian timekeeping

Studies in various model organisms reveal that the expression level of a substantial part of the transcriptome and the proteome exhibits regular daily oscillations. These oscillations are translated to physiological and behavioral rhythms allowing organisms to efficiently anticipate and respond to the daily and seasonally changing environment (e.g., temperature and light). A rather small subset of evolutionary conserved genes drives these oscillations and constitutes the core molecular circadian clock. Here, we review the multiple mechanisms that coexist at various molecular and cellular levels and are involved in the metazoan circadian clock, including transcription/translation negative feedback loops, post‐transcriptional and post‐translational modifications, intracellular translocation, and intercellular signaling. WIREs RNA 2011 2 312–320 DOI: 10.1002/wrna.58 This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein–RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Development