Researchers at Dartmouth Medical School said that the 24-hour body clock remains unchanged with temperature.
Researchers at Dartmouth Medical School said that the 24-hour body clock remains unchanged with temperature and metabolism.
Circadian systems are biological oscillators that orchestrate activities through an elaborate network of interactive proteins and feedback loops. They depend upon transfer of phosphate groups, called phosphorylation, to clock proteins for setting the 24-hour cycle.Drs. Jay Dunlap and Jennifer Loros, who led both studies, have revealed that both studies looked at phosphorylation of the frequency (FRQ) clock protein, a central feedback cog in the fungal clock system.
They have documented the workings of FRQ and most other components in the Neurospora clock.
"The Cell paper describes how the cell uses phosphorylation of a clock protein to keep the period length of the cycle close to the same across a range of temperatures. This phenomenon, called temperature compensation, is one of the few canonical properties of rhythms that still lack molecular description," said Dunlap.
The researchers say that their research suggests a new role for the clock-associated enzyme, casein kinase (CK)2, as a key control for temperature compensation. They pursued two uncharacterised circadian protein mutants shown to affect compensation in an unusual way, and identified different subunits of the same enzyme, CK2.
The team developed new ways to manipulate the genome, and showed, by controlling expression, that the level of CK2 dictates the form of compensation through the phosphorylation of the clock protein FRQ.
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The second study traced protein interactions throughout the cycles to show how phosphorylation controls circadian rhythm. It pinpointed a near record number of modifications on FRQ and described how each appears and disappears over the day.
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The two study have been published in the journal Cell.
Source-ANI
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