The FMR1 Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the Raji human B lymphocyte line, featuring targeted disruption of the FMR1 gene. This loss-of-function model eliminates FMRP expression, and the polyclonal format provides a heterogeneous mixture of edited cells, reflecting diverse knockout genotypes without clonal selection, ideal for robust population-level analyses.
Derived from an Epstein-Barr virus-positive Burkitt’s lymphoma, Raji B cells serve as a well-established model for antigen presentation and immunoglobulin production. Their stable proliferation, defined surface marker profile, and tractable genetic manipulation make them a powerful platform for studying signal transduction and translational regulation in the immune system. The line is widely used in investigations of EBV-driven lymphomagenesis and B cell receptor signaling.
FMR1 encodes the RNA-binding protein FMRP, a translational repressor that forms complexes with CYFIP1, FXR1P, FXR2P, and Argonaute proteins to control the stability and translation of target mRNAs, including MAP1B, ARC, and BDNF. FMRP activity is regulated upstream by mGluR5, CREB1, and BDNF signaling, and it functions within the mTOR pathway alongside key components such as 4E-BP, eIF4E, PI3K, AKT, TSC1/2, and Rheb. Disruption of FMR1 in this system abolishes FMRP-mediated repression, leading to dysregulation of synaptic-like signaling cascades that are increasingly recognized in lymphocyte biology.
By eliminating FMRP in a B lymphocyte context, this knockout model recapitulates core molecular features of Fragile X syndrome and related disorders, including fragile X-associated tremor/ataxia syndrome, fragile X-associated primary ovarian insufficiency, and autism spectrum disorders. The loss of FMRP-dependent translational control may alter pathways relevant to antigen presentation and antibody production, offering a unique system to dissect connections between mRNA metabolism and immune cell function.
These cells are suited for diverse experimental applications: analyzing FMRP?CRNA interactions via RNA immunoprecipitation and polysome profiling, quantifying FMRP target mRNAs (BDNF, ARC) by RT-qPCR, and performing compound screens against the mGluR5?CPI3K?CAKT?CmTOR axis. Additional assays include Western blotting for FMRP, flow cytometry for B cell markers, and MTT-based viability testing. For further details or custom requests, contact Ascent Research.
