NEMF Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout population featuring targeted disruption of the NEMF gene in the Raji B lymphoblastoid cell line. This polyclonal format provides a heterogeneous pool of cells with diverse loss-of-function mutations, enabling robust assessment of NEMF-dependent phenotypes without clonal artifacts. These cells serve as a versatile loss-of-function model for studying ribosome-associated quality control in human B lymphocytes and Burkitt’s lymphoma biology.
Raji is an EBV-positive Burkitt’s lymphoma-derived B cell line that retains key features of mature B lymphocytes, including surface immunoglobulin expression, antigen presentation, and antibody production capacity. Widely used in immunology and cancer research, Raji cells provide a relevant system for investigating B cell receptor signaling, lymphomagenesis, and translational quality control in a B cell context. Their rapid proliferation and genetic tractability facilitate knockout studies, while maintaining intrinsic proteotoxic stress pathways associated with high immunoglobulin synthesis.
NEMF is a core RQC component that recognizes stalled 60S ribosomal subunits. It acts downstream of ZNF598, which monoubiquitinates ribosomal proteins upon translational arrest. NEMF recruits the E3 ligase LTN1, which polyubiquitinates incomplete nascent chains, with TCF25 modulating complex assembly. The ATPase VCP/p97 extracts these substrates for proteasomal degradation, after which ABCE1 recycles the ribosomal subunit. This cascade ensures clearance of aberrant translation products, maintaining proteostasis under basal and stress conditions.
Disruption of NEMF in Raji cells is significant for studying RQC in B lymphocytes and Burkitt’s lymphoma, where proteotoxic stress from high-level antibody production and EBV-driven proliferation may overwhelm protein degradation machinery. This model enables investigation of NEMF-dependent responses to translational inhibitors (e.g., anisomycin) or oxidative stress, and assessment of ubiquitin-proteasome system function. It can also be used to evaluate synergy with proteasome inhibitors, which are therapeutically relevant in B cell malignancies.
Researchers can utilize Western blotting and co-immunoprecipitation to monitor RQC complex assembly and substrate ubiquitination. Ribosome profiling and puromycin incorporation assays quantify translational stalling and rescue. Proteasome activity measurements, combined with flow cytometric analysis of apoptosis and cell cycle, define functional outcomes of NEMF loss. RNA-seq transcriptomics reveals downstream gene expression changes. The model is also suited for drug sensitivity screens targeting proteostasis. For further information, contact Ascent Research.
