Unc-51 like autophagy activating kinase 1 (ULK1) (ULK1)

The autophagy pathway downstream of mTORC1 is a fundamental cellular process regulated by the Unc-51 like autophagy activating kinase 1 (ULK1) complex, which serves as the primary initiator of autophagosome formation (Kim et al., 2011, Nature). In nutrient-replete conditions, the mechanistic target of rapamycin complex 1 (mTORC1) phosphorylates ULK1 at Ser757, preventing its activation and thereby suppressing autophagy (Egan et al., 2015, Molecular Cell). When mTORC1 is inhibited by stress or pharmacological agents, ULK1 is dephosphorylated and activated, triggering a cascade involving the PI3K Class III complex (VPS34) and ATG proteins to sequester cytoplasmic components for lysosomal degradation (Mizushima & Komatsu, 2011, Cell). This pathway is a significant therapeutic target in oncology, as many tumors utilize autophagy to survive metabolic stress and escape treatment-induced apoptosis (Galluzzi et al., 2017, EMBO Journal). Conversely, in neurodegenerative diseases, enhancing this pathway is explored as a means to clear misfolded protein aggregates like amyloid-beta or alpha-synuclein (Djajadikerta et al., 2020, Frontiers in Cell and Developmental Biology). Pharmacological modulation primarily targets ULK1 or its downstream effectors like VPS34 to either inhibit or induce the autophagic flux depending on the clinical indication (Deciphera Pharmaceuticals, 2023).

Other names

ULK1 complexAutophagy-initiating complexATG1 complexUnc51.1Unc-51 like kinase 1ULK1/ATG13/FIP200/ATG101 complex

Inhibition of the ULK1 kinase complex or the downstream VPS34-containing PI3K Class III complex to prevent the nucleation and expansion of autophagosomes.