Brain complexity: circadian controls (Introduction)

by David Turell , Thursday, October 01, 2015, 18:01 (3341 days ago) @ David Turell

Our 24 hour rhythm helps us sleep and is clocked by the sun's 24-hour day/night arrangement. Molecular controls have been found:-http://phys.org/news/2015-10-body-scientists-mechanism-circadian-clock.html-"Over the past few decades, research has advanced our understanding of the circadian clock. One of the proteins critical for determining the timing of the clock, as well as the timing of sleep, is Period2 (PER2).-"In the current study, published 1 October 2015 in the journal Molecular Cell and led by Professor David Virshup from Duke-NUS and Professor Daniel Forger from Michigan, the findings shed light on how PER2 regulates our circadian clock. It also clarifies how the clock adapts to diverse conditions such as temperature and metabolic changes.-"The research team found that the stability of PER2 is dependent on a process called phosphorylation, in which phosphates are added at key sites to influence the function of PER2. Dr Virshup and the team discovered that phosphorylation acts as a switch. This 'phosphoswitch' leads to two alternative fates for PER2: increased stability or increased degradation.-"The researchers report that this phosphoswitch is sensitive to changes in temperature and metabolic signals and so it fine-tunes clock speed as needed. Usually, the rate of a biochemical reaction increases as the temperature rises, so in this case the speed of the body clock should increase if the temperature rises. However, the team showed that at higher temperatures, the phosphoswitch ensures that degradation of PER2 is slower, therefore maintaining the speed of the body clock.-"'This study sheds light on one of the biggest mysteries of the circadian clock in the last 60 years and has helped to explain some of the basic mechanisms that govern the timing of the clock," explained Dr Virshup, Director of the Cancer and Stem Cell Biology Programme at Duke-NUS and Professor of Pediatrics at Duke University. "By using both biochemical analysis and mathematical modelling we demonstrated how the core circadian clock keeps to a 24-hour cycle despite temperature changes and metabolic changes.'"-Comment: these molecular controls are automatic. Why can't it be understood that if our multicellular bodies have so much automaticity in our cellular activity, that it is obvious can bacteria simply work automatically? Automaticity if properly regulated will look just like intelligent action from the outside of all bacteria.