Atg13, a component of the ULK1 kinase complex in vertebrates (equivalent to the Atg1 kinase complex in yeast), is essential for autophagy initiation. Autophagy is a conserved intracellular degradation process involved in recycling cytoplasmic components and removing cellular debris, pathogens, etc. Atg13 functions in sensing nutritional status signals, recruiting downstream ATG proteins to the autophagosome formation site, and governing autophagosome formation [2,3].

Atg13-deficient mice, similar to FIP200-deficient mice, die in utero. Atg13-deficient embryos show growth retardation and myocardial growth defects. In cultured fibroblasts, Atg13 deficiency blocks autophagosome formation at an upstream step. Also, deletion of Atg13 enhances sensitivity to TNF-α-induced apoptosis [4]. In PM2.5-induced pulmonary fibrosis, PM2.5-downregulated ALKBH5 protein expression promotes m6A modification of Atg13 mRNA at site 767 in lung epithelial cells, and Atg13-mediated ULK complex positively regulates autophagy and inflammation [1].

In conclusion, Atg13 is crucial for autophagy and cardiac development. Gene knockout mouse models of Atg13 have revealed its roles in autophagy-related biological processes and diseases such as pulmonary fibrosis. These findings contribute to understanding the molecular mechanisms underlying autophagy-related disorders and may provide potential therapeutic targets for diseases like PM2.5-induced pulmonary fibrosis.