The HEATR5B Knockout HeLa Polyclonal Cells represent a versatile CRISPR/Cas9-edited polyclonal knockout cell population derived from the HeLa cell line, engineered for targeted disruption of the HEATR5B gene. Unlike clonal cell lines, this polyclonal population comprises a heterogeneous mixture of cells, each carrying distinct gene disruptions, thereby reducing clonal artifacts and enabling robust loss-of-function analysis. The product is generated through CRISPR/Cas9-mediated gene disruption, ensuring efficient ablation of HEATR5B protein expression. This model is particularly suited for studying mTORC1 signaling dynamics and autophagy regulation in a human epithelial cancer context.
The host HeLa cell line is an immortalized human epithelial cell line established from cervical adenocarcinoma, notable for its HPV18-positive status. HeLa cells are extensively employed in cancer biology due to their well-characterized genome and capacity for rapid proliferation. Their inherent signaling networks, including active amino acid sensing and growth factor pathways, make them an optimal platform for investigating lysosomal mTORC1 regulation. The HPV18 presence adds relevance for studies exploring viral oncoprotein interactions with host cellular pathways.
HEATR5B acts as a molecular scaffold that orchestrates mTORC1 lysosomal localization and kinase activity, essential for cellular responses to amino acids and growth factors. Upon nutrient stimulation, HEATR5B interacts with mTOR, Raptor, v-ATPase, and the Ragulator complex to drive Rag GTPase-dependent recruitment of mTORC1 to lysosomal membranes. Disruption of HEATR5B via knockout abolishes this lysosomal targeting, markedly reducing phosphorylation of downstream effectors S6K and 4EBP1, thereby dampening the mTORC1-S6K-4EBP1 signaling cascade. In addition, impaired mTORC1 activity alters ULK1 phosphorylation, thereby affecting autophagy initiation, and influences TFEB-mediated lysosomal biogenesis. Consequently, HEATR5B knockout uncouples amino acid sensing from mTORC1 activation, leading to altered autophagic flux and metabolic adaptation.
In HeLa cervical adenocarcinoma cells, HEATR5B knockout offers a clinically relevant model to explore mTORC1-mediated growth and autophagy in cancer. Cervical tumors often exhibit elevated mTORC1 activity, supporting proliferation and suppressing autophagy. Ablating HEATR5B allows investigation of lysosomal mTORC1 positioning in oncogenic signaling, and how autophagy modulation affects metabolic stress resistance and drug sensitivity. This model is particularly valuable for examining how HPV18-driven transformation intersects with mTORC1 signaling, as viral E6 and E7 proteins are known to modulate PI3K/AKT/mTOR pathways. Thus, these cells enable dissection of tumor-specific nutrient-sensing dependencies.
Experimental applications include assessing mTORC1 activity via phospho-S6K Western blotting, visualizing mTOR lysosomal localization by immunofluorescence, and measuring autophagic flux through LC3 turnover or p62 degradation. Co-immunoprecipitation assays can validate disrupted interactions among mTOR, Raptor, and associated factors. The knockout cells are suitable for drug resistance studies and research into metabolic and neurodegenerative diseases where mTORC1 signaling is dysregulated. For detailed product information or technical support, please contact Ascent Research.
