The MTMR1 Knockout Raji Polyclonal Cells are a genetically modified human B-cell population generated by CRISPR/Cas9-mediated disruption of the MTMR1 gene within the Raji cell line. This polyclonal knockout model provides a heterogeneous pool of edited cells, enabling the study of MTMR1 loss-of-function in a physiologically relevant lymphoid background. The polyclonal format retains the genetic diversity inherent to the parental Raji line while introducing targeted gene disruption, facilitating population-level analyses of phosphoinositide metabolism and autophagy regulation.
The parental Raji cell line is a human Burkitt lymphoma-derived B-lymphocyte model established from an EBV-positive Nigerian patient. These cells express characteristic B-cell markers including CD19, CD20, and surface IgM, but lack surface IgG, making them a widely used system for investigating B-cell biology, lymphomagenesis, immune signaling, and EBV-associated pathogenesis. The Raji background offers a cancerous B-cell context that is particularly suited for examining oncogenic signaling pathways and endosomal trafficking dynamics.
MTMR1 encodes a lipid phosphatase that dephosphorylates phosphatidylinositol 3-phosphate (PI3P) and PI(3,5)P2 on endosomal membranes, counteracting PI3K/AKT/mTOR signaling and regulating endosome maturation and autophagy. Its activity is controlled upstream by B-cell receptor signaling, NF-??B, and autophagy stimuli, while downstream it modulates LC3 lipidation, p62/SQSTM1 degradation, and WIPI2 recruitment. MTMR1 forms complexes with MTMR12, hVps34, Beclin1, and Rab GTPases such as Rab5 and Rab7, linking phosphoinositide turnover to actin cytoskeletal dynamics.
Knockout of MTMR1 in Raji B-cells leads to elevated PI3P levels on endosomal membranes, which disrupts endosomal maturation and autophagy flux. This perturbation likely alters B-cell receptor trafficking, antigen processing, and downstream signaling cascades such as PI3K/AKT, providing a powerful tool for dissecting how phosphoinositide metabolism governs lymphocyte function and transformation. The model is particularly valuable for studying the intersection between autophagy, endosomal sorting, and immune signaling in a B-cell lymphoma context, and for exploring the role of myotubularin family proteins in lymphomagenesis and therapy resistance.
This knockout model enables investigation of phosphoinositide signaling in B-cells, autophagy regulation in lymphoma, and endosomal trafficking using Western blotting (MTMR1, LC3, p62), immunofluorescence (EEA1, Rab5), flow cytometry (phospho-AKT), and BCR stimulation assays. It also supports myotubularin family studies and drug target validation for myopathy. For further details, contact Ascent Research.
