MEF2D Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population targeting the MEF2D gene in the human Raji B lymphocyte cell line. These cells provide a loss-of-function model for studying MEF2D-dependent transcriptional regulation.
Raji cells are derived from an EBV-positive Burkitt’s lymphoma, widely used as a cancerous B lymphocyte model. They express B cell receptors and downstream signaling machinery, making them ideal for studying BCR signaling and lymphomagenesis.
MEF2D encodes a member of the myocyte enhancer factor 2 family of transcription factors. In B lymphocytes, MEF2D is primarily activated downstream of B cell receptor (BCR) engagement, where calcium influx triggers calmodulin-dependent kinase IV (CaMKIV) and ERK5/MAPK7 to phosphorylate MEF2D, relieving repression by HDAC4 and promoting nuclear translocation. Once in the nucleus, MEF2D binds A/T-rich DNA elements and forms complexes with coactivators such as p300/CBP and NFATc2, while interactions with Cabin1 and 14-3-3 proteins further modulate its activity. MEF2D transcriptionally regulates a network of genes critical for B cell fate, including the AP-1 component c-JUN, the pro-survival factor BCL2L1 (Bcl-xL), the nuclear orphan receptor NR4A1 (Nur77), and the cell cycle inhibitor CDKN1A (p21). The canonical signaling relay from BCR through SYK, BTK, PLC??2, and calcium mobilization to CaMKIV and MEF2D therefore couples antigen recognition to proliferation and survival decisions.
In the Raji background, MEF2D is constitutively phosphorylated and active due to tonic BCR signaling and EBV latent gene expression, contributing to the uncontrolled proliferation characteristic of Burkitt’s lymphoma. Ablation of MEF2D in this polyclonal knockout population enables dissection of its dependency in lymphomagenesis, including effects on cell cycle progression, apoptosis resistance, and downstream transcriptional programs. This model provides a physiologically relevant system for investigating MEF2D-driven oncogenic mechanisms and for evaluating targeted therapies directed at the BCR-MEF2D axis.
These knockout cells are suitable for functional genomics, drug screening, and mechanistic studies of B cell malignancies. Representative assays include Western blotting for MEF2D loss, RT-qPCR for downstream target expression (e.g., c-JUN, BCL2L1), flow cytometry for B cell surface markers, CellTiter-Glo or BrdU proliferation assays, Annexin V apoptosis assays, and phospho-specific flow or immunoblotting for BCR pathway activation (e.g., phospho-SYK, phospho-ERK). The polyclonal format preserves population-level heterogeneity, enabling robust statistical analysis in pooled knockout screens. For additional information or to discuss custom projects, please contact Ascent Research.
