Glycine required for improved autophagy and healthier recovery during macroautophagy

Writing about this more but basically:

  1. Enhancement of Autophagy: Research suggests that glycine can enhance the autophagic process. Glycine is believed to activate certain pathways or signals that lead to increased autophagy. For instance, it may influence the mTOR (mechanistic target of rapamycin) pathway, which is a crucial regulator of autophagy.

  2. Protection During Autophagy: Glycine also plays a protective role for cells during autophagy. It can help maintain the integrity of cells as they go through this rigorous cleaning process, ensuring that the cells’ essential structures are preserved while the unnecessary or damaged parts are recycled.

  3. Contribution to Glutathione Production: Glycine is a key component in the synthesis of glutathione, a potent antioxidant in the body. While not directly involved in autophagy, glutathione helps protect cells from oxidative stress, which can indirectly support the autophagic process by maintaining cellular health and stability.

  4. Starvation and Autophagy: Autophagy is often triggered by cellular stress, including nutrient deprivation or starvation. Glycine is known to mimic the effects of dietary restriction without actually reducing calorie intake, potentially stimulating autophagy through pathways similar to those activated during nutrient deprivation.

    The Atg8/LC3 system is the second key process involved in the growth of the phagophore, a structure involved in autophagy. Here’s how this system works in more understandable terms:

  5. Atg8 Processing: The process begins when the protein Atg8 is modified by the enzyme Atg4, which cuts it in a way that exposes a glycine (a type of amino acid) at one end of Atg8.

  6. Activation and Transfer: The enzyme Atg7, acting similarly to an E1 enzyme, activates the modified Atg8. It then hands off Atg8 to another enzyme called Atg3, which functions like an E2 enzyme.

  7. Attachment to PE: The glycine end of Atg8 is then attached to a lipid called phosphatidylethanolamine (PE). This attachment process is assisted by the conjugate of Atg12 and Atg5, which might work like an E3 enzyme to help this attachment happen.

  8. Membrane Association and Release: Once attached to PE, the Atg8 (now known as Atg8-PE) associates with membranes. However, it can be removed, or released from these membranes, by a second cut made by Atg4.

  9. Importance of Deconjugation: The removal of Atg8-PE from membranes, called deconjugation, is regulated in a way that’s not fully understood. However, it’s known to be crucial for autophagy. If this step doesn’t occur properly, it can lead to issues in the autophagy process.

In simpler terms, this system is all about preparing Atg8, attaching it to a lipid so it can associate with membranes, and then making sure it can be removed properly. Each step is crucial for the autophagy process to function correctly.