Wonder why you wake up in the morning effortlessly, even without the shrill alarm?

A team led by Indian-American scientist, Satchidananda Panda, has identified a new 'wake-up' gene that activates the biological clock from its restful state every morning.

"The body is essentially a collection of clocks," said Panda, associate professor at the Salk Institute Regulatory Biology Lab, who led the research with Luciano DiTacchio, post-doctoral research associate, reports the journal Science.

"We roughly knew what mechanism told the clock to wind down at night, but we didn't know what activated us again in the morning," added Panda, who did his B.Sc from Orissa University of Agriculture and Technology, at Bhubaneswar in India.

"Now that we've found it, we can explore more deeply how our biological clocks malfunction as we get older and develop chronic illness," said Panda, according to a Salk statement.

The discovery may help explain the genetic underpinnings of sleeplessness, ageing and chronic illnesses, such as cancer and diabetes, opening the way to potential cures.

Salk researchers and their collaborators described how the gene KDM5A encoded a protein, JARID1a, that served as an activation switch to maintain our circadian rhythm.

The discovery fills in a missing link in the molecular mechanisms that control our daily wake-sleep cycle. The central player of our biological clock is a protein called PERIOD (PER). The number of PER proteins in each of our cells rises and falls every 24 hours.

Our cells use the level of PER protein as an indicator of the time of the day and tell our body when to sleep or be awake.