EIF3CL Knockout HEK293T Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population in which the EIF3CL gene, encoding a putative scaffold subunit of the eIF3 translation initiation complex, has been disrupted across the host cell pool. This knockout format generates a heterogeneous mixture of cells bearing a spectrum of loss-of-function mutations, which mitigates clonal bias and more faithfully models the variability of gene disruption relevant to population-level translational studies. Such polyclonal cells are particularly suitable for experiments requiring broad representation of gene targeting outcomes.
The host HEK293T cell line is a highly transfectable derivative of human embryonic kidney HEK293 cells, immortalized and optimized for robust protein expression, viral production, and efficient CRISPR/Cas9 editing. Stably expressing the SV40 large T antigen, these cells support episomal replication and exhibit rapid growth, making them a preferred platform for investigating mTOR-dependent translation and oncogenic signaling.
EIF3CL is hypothesized to be a core component of the ~800 kDa eIF3 complex, which orchestrates the loading of the 43S preinitiation complex onto the 5?? cap of mRNAs during cap-dependent translation initiation. Within this multiprotein assembly, EIF3CL interacts with numerous other subunits (e.g., eIF3A, eIF3B, and eIF3L) and with eIF4G, thereby bridging the mRNA cap-binding complex and the 40S ribosomal subunit. The activity of EIF3CL is tightly regulated by the mTORC1 kinase complex, a central nutrient and growth factor sensor. In response to signals such as insulin and IGF-1, mTORC1 phosphorylates key downstream effectors including RPS6KB1 (S6K1) and EIF4EBP1 (4E-BP1). Phosphorylation of EIF4EBP1 relieves its inhibition of eIF4E, facilitating eIF4E?CeIF4G association and enhancing eIF3-complex recruitment to capped mRNAs. This signaling axis selectively upregulates translation of oncogenic mRNAs with highly structured 5?? UTRs, such as MYC, CCND1, and VEGF, linking EIF3CL to cellular proliferation and tumorigenesis.
HEK293T cells exhibit constitutive mTORC1 activity and high rates of global protein synthesis, a context in which EIF3CL disruption is expected to significantly attenuate cap-dependent translation. Because EIF3CL dysregulation has been reported in breast cancer and hepatocellular carcinoma, this polyclonal knockout model provides a powerful system for disentangling the contributions of the eIF3 complex to translational reprogramming in cancer. Studies using these cells can delineate how loss of EIF3CL affects the translation of specific mRNAs and the overall proteome, without the confounding effects of clonal selection.
This product supports polysome profiling with RNA-seq to identify EIF3CL-dependent transcripts, dual-luciferase reporter assays to quantify cap-dependent initiation, and puromycin incorporation assays to measure global protein synthesis. It enables co-immunoprecipitation of eIF3 complexes, high-throughput screening for translation inhibitors, and cycloheximide chase coupled with Western blotting to examine downstream targets like CCND1. For more information, please contact Ascent Research.
