The LAPTM4A Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population derived from the Raji B lymphocyte cell line, featuring targeted disruption of the LAPTM4A gene (lysosomal-associated protein transmembrane 4A). This product provides a loss-of-function model for LAPTM4A, a lysosomal membrane protein implicated in lysosomal trafficking and amino acid sensing. The cells are engineered using CRISPR/Cas9-mediated gene editing to achieve gene disruption without single-cell cloning, maintaining polyclonal heterogeneity that enables robust and reproducible functional studies. The polyclonal nature avoids clonal selection artifacts and is well-suited for population-level analyses in cancer cell biology.
The host cell line, Raji, is a suspension B lymphocyte line derived from an Epstein-Barr virus (EBV)-positive Burkitt lymphoma. Raji cells are a classic model for B-cell malignancies, lymphoma biology, and immune cell signaling. Their EBV-positive status supports studies of viral latency and oncogenic transformation, while their rapid growth and ease of culture facilitate high-throughput drug screening and autophagy assays. This cell background is particularly relevant for lymphoma research, providing a clinically pertinent context for investigating multidrug resistance pathways and lysosomal function in B-cell cancers.
LAPTM4A encodes a multi-pass transmembrane protein localized primarily to lysosomes and late endosomes, where it regulates lysosomal positioning, amino acid sensing, and mTORC1 signaling. Mechanistically, LAPTM4A is positively regulated by the transcription factor TFEB and responds to cellular stress signals. It interacts directly with v-ATPase and mTORC1, and acts within a signaling network that includes mTOR, RHEB, LAMP1, and RAB7. Functionally, LAPTM4A promotes mTORC1 activation and autophagic flux, while also facilitating the subcellular sequestration of chemotherapeutic drugs such as doxorubicin. Disruption of LAPTM4A accordingly impairs lysosomal trafficking, attenuates mTORC1 signaling, and may compromise drug resistance mechanisms.
In the Raji B-lymphoma context, LAPTM4A knockout constitutes a valuable model for dissecting the contributions of lysosomal membrane proteins to tumor cell survival and drug resistance. Loss of LAPTM4A is expected to disturb lysosomal homeostasis, alter autophagic degradation, and reduce the capacity for drug sequestration, potentially sensitizing cells to chemotherapeutic agents. This polyclonal knockout population enables researchers to study the interplay between mTORC1-driven proliferation and autophagy-mediated cytoprotection in a well-defined lymphoma background, offering insights into lysosome-targeted therapeutic strategies.
Typical applications of this knockout model include detailed investigations of lysosome biology and autophagy regulation, using assays such as Western blotting for LAPTM4A expression, immunofluorescence staining for LAMP1 and LC3 puncta, and autophagy flux measurements with lysosomal inhibitors. Drug sensitivity can be assessed via doxorubicin dose?Cresponse assays and apoptosis evaluated by flow cytometry. Transcriptional changes can be profiled by RNA-seq, and mTORC1 pathway activity monitored through phospho-S6K1 analysis. These cells support a wide range of research areas including drug-resistant cancers, acute myeloid leukemia, and lymphoma. For further information or technical inquiries, please contact Ascent Research.
