The ATP9B Knockout HT29 Polyclonal Cells product is a CRISPR/Cas9-edited polyclonal knockout cell population derived from the HT29 human colorectal adenocarcinoma epithelial cell line. This genetically modified pool results from targeted disruption of the ATP9B gene, generating a heterogeneous loss-of-function model suitable for studying ATP9B-dependent processes. The polyclonal format provides a robust experimental system by averaging out clonal variability, making it ideal for applications where knockout efficiency at the population level is sufficient. The cells retain the well-characterized epithelial morphology and adherent growth properties of the parental HT29 line, offering a physiologically relevant context for investigating ATP9B??s role in lipid transport and membrane biology.
The HT29 cell line, established from a primary colorectal adenocarcinoma, is a widely used model for intestinal epithelial barrier function and colon cancer research. These cells form polarized monolayers with tight junctions, making them valuable for transport studies and barrier integrity assays. Their origin in a colorectal adenocarcinoma background also renders them highly relevant for exploring oncogenic signaling pathways and drug responses. As a model system, HT29 cells express key epithelial markers and maintain the capacity for mucin production, further supporting studies of epithelial differentiation and disease.
ATP9B encodes a P4-ATPase phospholipid flippase that translocates aminophospholipids, particularly phosphatidylserine and phosphatidylethanolamine, from the exofacial to the cytofacial leaflet of cellular membranes, thereby preserving membrane lipid asymmetry. This function is essential for endosomal trafficking, autophagic flux, and the regulation of mTORC1 signaling. ATP9B forms functional complexes with the CDC50A and CDC50B chaperones and interacts with clathrin adaptor AP-2 and sorting nexins to direct subcellular localization. Its activity is regulated upstream by LXR transcription factors, SREBP, and mTORC1, and it functions downstream to modulate membrane lipid composition, which in turn influences apoptosis through controlled phosphatidylserine exposure, endosomal sorting, and mTORC1 activation.
In the HT29 colorectal adenocarcinoma context, loss of ATP9B disrupts critical cellular processes. Impaired flippase activity leads to abnormal lipid distribution at the plasma membrane and endosomes, affecting endocytic recycling, autophagy induction, and the execution of apoptosis. These defects can compromise intestinal epithelial barrier integrity, as lipid asymmetry is crucial for tight junction functionality and cellular polarization. Furthermore, ATP9B deficiency may alter sensitivity to chemotherapeutic agents, given the role of phospholipid scrambling in drug-induced apoptosis. Thus, this knockout model provides a platform for dissecting the interplay between lipid transport and colon cancer progression, as well as the basis for neurodevelopmental disorders associated with ATP9B mutations.
Researchers can employ the ATP9B Knockout HT29 Polyclonal Cells in a variety of assays to explore lipid flippase biology. Applications include studying intestinal epithelial lipid transport mechanisms using NBD-phospholipid uptake assays, evaluating autophagic flux by LC3-II western blotting, and assessing early apoptosis via Annexin V staining, which detects phosphatidylserine externalization. Barrier function studies with transwell TEER measurements, endocytosis assays, chemosensitivity screens, and migration experiments are also facilitated. This polyclonal knockout population is particularly suited for population-level readouts and pooled screens. For further technical details and assistance with experimental design, please contact Ascent Research.
