ATG4A Knockout A-549 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population derived from A-549 lung adenocarcinoma cells, with disruption of the ATG4A gene to eliminate its function. This heterogeneous knockout model avoids clonal artifacts, enabling robust autophagy studies while retaining parental genetic diversity. The polyclonal format is beneficial for bulk phenotypic analyses in a cancer-relevant epithelial context.
The A-549 cell line is an adherent epithelial model from lung adenocarcinoma of a 58-year-old male. It exhibits type II alveolar cell characteristics and is widely used for respiratory epithelium studies and non-small cell lung cancer research. A-549 cells are valuable for investigating cancer biology, drug metabolism, and host-pathogen interactions.
ATG4A encodes a cysteine protease that plays a key role in autophagosome biogenesis. It processes LC3 (MAP1LC3B) and GABARAP subfamily precursors by cleaving C-terminal amino acids to expose a glycine residue, enabling PE conjugation and membrane insertion. ATG4A also deconjugates LC3-PE from outer autophagosomal membranes, facilitating autophagosome maturation and lysosomal fusion. Its activity is regulated by nutrient-sensing inputs: mTORC1 suppresses autophagy under fed conditions, while AMPK and ROS stimulate ATG4A-mediated processing upon nutrient deprivation. Transcription factors TFEB and FOXO3 upregulate ATG4A expression, integrating it into broader autophagy-lysosome pathways. ATG4A directly interacts with ATG7, ATG3, and its substrates MAP1LC3B, GABARAP, and GABARAPL1, coordinating with the ATG12?CATG5?CATG16L1 conjugation complex.
In A-549 cells, ATG4A knockout impairs autophagy flux, providing a powerful model to examine autophagy??s role in lung adenocarcinoma. Tumors often exploit autophagy to survive hypoxia and metabolic stress, and ATG4A-mediated LC3 processing is critical for this protection. This polyclonal knockout population is ideal for studying how autophagy disruption affects tumor proliferation, drug resistance, and the epithelial-mesenchymal transition. It also enables investigation of autophagy-dependent interactions within the tumor microenvironment, including metabolic adaptation and immune modulation.
These cells support a wide range of assays, such as Western blotting for LC3B lipidation, fluorescence microscopy of LC3 puncta, and autophagy flux assays with chloroquine. Additional approaches include cell viability under starvation, RT-qPCR of autophagy genes, co-immunoprecipitation to verify disrupted ATG4A?CLC3 binding, and flow cytometry using tandem fluorescent LC3 reporters. The model is also amenable to tumor xenograft studies and high-throughput screening of autophagy-modulating drugs. For more information, please contact Ascent Research.
