Thursday, December 13, 2007

Genetic switch for internal body clock discovered



A team of researchers including an Indian scientist have identified the chemical switch that facilitates the genetic mechanism controlling human body's circadian rhythms or the internal body clock.

The findings by the researchers at University of California, Irvine, have discovered the precise information regarding the body's circadian rhythms till date and this would specifically lead to a new pharmaceutical approach for sleep disorder treatments.

The study was authored by Paolo Sassone-Corsi, distinguished Professor and Chair of Pharmacology and Saurabh Sahar, Department of Pharmacology, School of Medicine, UC.

It was discovered that the genes controlling circadian rhythms were stimulated by a single amino acid.

Amino acids are the building blocks of proteins and this surprised Sassone-Corsi as he found that only a single amino acid activates the body-clock mechanism because of the complex genes involved.

"Because the triggering action is so specific, it appears to be a perfect target for compounds that could regulate this activity," Nature quoted, Sassone-Corsi as saying.

He added: "It is always amazing to see how molecular control is so precise in biology."

The Circadian rhythms are the body's in built system of time-tracking, which foresee environmental changes and adapts to the appropriate time of day. They also regulate a number of body functions, right from sleep patterns and hormonal control to metabolism and behavior.

Almost 10 pct to 15 pct of all human genes are controlled through circadian rhythms. Any kind of disturbance of these rhythms can dramatically influence human health and has been linked to insomnia, depression, heart disease, cancer and neurodegenerative disorders.

Circadian rhythms are triggered by the gene clock and its partner BMAL1.

This research team, last year uncovered that clock functions as an enzyme that modifies chromatin, the protein architecture of a cell's DNA.

However, in the current study, the researchers' team discovered that a single amino acid in the BMAL1 protein undergoes a alteration that activates the genetic chain of events associated with circadian rhythms.

It was also noted, if this amino-acid modification is impaired in any way, the switching mechanism can be dropped, which can be the genetic support for circadian-rhythm-related ailments.

at present, Sassone-Corsi is testing antibodies targeting this BMAL1 amino-acid activity.

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