Autophagy Signaling Transduction

What is Autophagy

Autophagy is a self-degradative process that is important for balancing sources of energy at critical times in development and in response to nutrient stress. Autophagy also plays a housekeeping role in removing misfolded or aggregated proteins, clearing damaged organelles, such as mitochondria, endoplasmic reticulum and peroxisomes, as well as eliminating intracellular pathogens.

Autophagy process consists of several sequential steps, including induction, cargo recognition and selection, vesicle formation, autophagsome-vacuole fusion, and breakdown of the cargo followed by release of the degradation products back into the cytosol. Different sets of autophagy related (Atg) proteins are involved in these steps and consist of the core autophagic machinery.

Autophagy Signaling Transduction

As well known, two well-characterized signaling cascades that negatively regulate autophagy, sense nutrient status, and activate cell division & growth are the mTOR and Ras-cAMP-PKA pathways. As a critical regulator of autophagy induction, mTOR kinase activates mTOR (Akt and MAPK-Erk signaling pathway) suppressing autophagy, and negatives regulation of mTOR (AMPK and p53 signaling pathway) promoting it. The ULK which play a similar role as the yeast Atg1, act downstream of the mTOR complex. ULK forms a large complex with Atg13 and the scaffold protein FIP200. More......

Autophagy Signaling Transduction

Cell Signaling Transduction