Circadian ribosome profiling reveals a role for the upstream open reading frame in sleep.

Many mammalian proteins have circadian cycles of production and degradation, and many of these rhythms are altered posttranscriptionally. We used ribosome profiling to examine posttranscriptional control of circadian rhythms by quantifying RNA translation in the liver over a 24-h period from circadian-entrained mice transferred to constant darkness conditions and by comparing ribosome binding levels to protein levels for 16 circadian proteins. We observed large differences in ribosome binding levels compared to protein levels, and we observed delays between peak ribosome binding and peak protein abundance.

Breaking self-regulation of Regnase-1 promotes its own protein expression.

The RNA-binding protein (RBP) Regnase-1 is an endonuclease that regulates immune responses by modulating target mRNA stability. Regnase-1 degrades a group of inflammation-associated mRNAs, which contributes to a balanced immune response and helps prevent autoimmune diseases. Regnase-1 also cleaves its own mRNA by binding stem-loop (SL) RNA structures in its 3'UTR.

A period without PER: understanding 24-hour rhythms without classic transcription and translation feedback loops.

Since Ronald Konopka and Seymour Benzer's discovery of the gene in the 1970s, the circadian rhythm field has diligently investigated regulatory mechanisms and intracellular transcriptional and translation feedback loops involving , and these investigations culminated in a 2017 Nobel Prize in Physiology or Medicine for Michael W. Young, Michael Rosbash, and Jeffrey C. Hall.

Systems Biology-Derived Discoveries of Intrinsic Clocks.

A systems approach to studying biology uses a variety of mathematical, computational, and engineering tools to holistically understand and model properties of cells, tissues, and organisms. Building from early biochemical, genetic, and physiological studies, systems biology became established through the development of genome-wide methods, high-throughput procedures, modern computational processing power, and bioinformatics. Here, we highlight a variety of systems approaches to the study of biological rhythms that occur with a 24-h period-circadian rhythms.