How cells respond to fasting

How cells respond to fasting

As modern life-styles and high calorie diets drive the  obesity levels up, researchers have found how cells respond to fasting and activate the process called autophagy, which means a healthier lifestyle can be promoted to help people maintain a healthy body weight.

Intermittent fasting, alternate-day fasting, and other forms of periodic caloric restriction are beneficial to maintain a healthy body weight and have gained popularity during the last few years. To respond to fasting, cells use autophagy, a cellular self-recycling process.

A team of researchers discovered how cells activate autophagy genes during fasting. In the paper published in the journal Cell Reports they have discovered proteins which are required for the transcription of autophagy genes.

The proteins are called Sequoia, YL-1 and Sir2, these proteins interact with the cytoplasmic autophagy-related protein Atg8a, homologous to mammalian LC3. These interactions recruit Atg8a in the nucleus to control the transcription of autophagy genes. This is the first study that uncovers a nuclear role of the cytoplasmic protein Atg8a.

The authors show that Atg8a interacts with YL-1, a component of a nuclear acetyltransferase complex, and that it is acetylated in nutrient-rich conditions. They also show that Atg8a interacts with the deacetylase Sir2, which deacetylates Atg8a during starvation to activate autophagy.

Lead author comments: "Understanding the molecular mechanisms of activation of autophagy genes during fasting will help us to use interventions to activate the autophagic pathways to maintain a normal body weight and promote healthy well-being."