The ATG4B Knockout A-549 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout population derived from the A-549 human lung adenocarcinoma cell line, featuring targeted disruption of the ATG4B gene. This model serves as a loss-of-function tool for investigating the role of ATG4B, a critical cysteine protease in the autophagy pathway. The polyclonal nature ensures a heterogeneous population with varying knockout efficiencies, suitable for bulk functional studies without clonal selection artifacts. The knockout cells are designed to support high-throughput screening and rigorous phenotypic analyses of autophagy modulation in cancer and beyond.
The A-549 host cell line, derived from a 58-year-old Caucasian male with lung carcinoma, is a widely used model for lung adenocarcinoma research. These cells exhibit adherent epithelial morphology and retain key characteristics of non-small cell lung cancer, including active oncogenic signaling and metabolic adaptability. A-549 cells are commonly employed in studies of drug metabolism, viral infection, and cancer biology, making them a robust platform for examining autophagy-related processes in a disease-relevant context.
ATG4B functions as a cysteine protease that processes members of the LC3 and GABARAP protein families, essential for autophagosome formation and maturation. The enzyme cleaves the C-terminal residues of pro-LC3 to expose a glycine residue necessary for conjugation to phosphatidylethanolamine on autophagosomal membranes, and also acts as a deconjugating enzyme to recycle LC3 from the outer membrane. ATG4B activity is regulated by upstream signals such as mTORC1 inhibition during starvation, AMPK activation, and transcription factors FOXO and ATF4 under ER stress. It interacts with LC3 family proteins, ATG7, ATG3, the ATG12-ATG5 conjugate, and the BECN1 complex, integrating into the broader autophagy network involving ULK1, ATG13, FIP200, PI3KC3, ATG14, and ATG16L1.
Disruption of ATG4B in A-549 cells provides a powerful model to dissect autophagy-dependent survival mechanisms in lung adenocarcinoma. Autophagy often promotes tumor cell resistance to chemotherapy and metabolic stress; thus, loss of ATG4B can sensitize cells to therapeutic agents or nutrient deprivation. This knockout model enables researchers to explore the interplay between ATG4B-mediated autophagic flux and oncogenic pathways, potentially revealing vulnerabilities that can be exploited for therapeutic intervention in non-small cell lung cancer and other autophagy-addicted malignancies.
Typical applications include investigating the role of ATG4B in drug resistance and tumor metabolism, as well as high-throughput screening of ATG4B inhibitors. Experimentally, users can perform Western blotting to assess the LC3B-II/LC3B-I ratio, fluorescence microscopy to visualize GFP-LC3 puncta, and autophagy flux assays with chloroquine or bafilomycin A1. Cell viability assays under nutrient starvation and drug sensitivity assays with chemotherapeutic agents further enable functional characterization. For additional information or to inquire about custom products, please contact Ascent Research.
