ATGProteine

ATGProteine are a group of autophagy-related proteins found in eukaryotic cells. Derived from ATG genes first described in the yeast Saccharomyces cerevisiae, these proteins are broadly conserved in plants and animals and are essential for the process of autophagy, in which cytoplasmic components are degraded and recycled within lysosomes or vacuoles.

In macroautophagy, ATGProteine participate in the core steps: initiation by the ULK1/ATG1 complex, nucleation by the class III phosphatidylinositol 3-kinase (PI3K) Beclin-1 complex, and expansion and closure via ubiquitin-like conjugation systems, including ATG8/LC3 and ATG12-ATG5-ATG16L1. ATG8/LC3 family members are lipidated and decorate forming autophagosomes, serving as markers and as adapters for cargo receptors such as p62/SQSTM1.

ATGProteine are reorganized during selective autophagy, enabling removal of damaged mitochondria or protein aggregates. The activity of these proteins is tightly regulated by nutrient status and signaling pathways such as mTOR. In mammals, multiple paralogs exist that can modulate autophagy efficiency and selectivity, reflecting the adaptation of the autophagy machinery to different cellular needs.

Dysregulation of ATGProteine function is associated with diseases including neurodegeneration, cancer, and infectious diseases. Conversely, pharmacological or genetic manipulation of ATGProteine is explored in therapeutic contexts and research as a way to modulate autophagy.

In research, ATGProteine are studied using gene knockout or knockdown approaches, overexpression, and fluorescent tagging to monitor autophagy flux and autophagosome formation.