The EIF3J Knockout HEK293T Polyclonal Cells are a CRISPR/Cas9-edited polyclonal cell population with targeted disruption of the EIF3J gene, encoding an essential subunit of the eukaryotic translation initiation factor 3 (eIF3) complex. This loss-of-function model is designed to study the roles of EIF3J in cap-dependent and IRES-mediated translation initiation, providing a flexible platform to investigate how EIF3J-dependent translation influences cellular processes. The polyclonal format preserves population-level heterogeneity, avoiding clonal artifacts and capturing a broad spectrum of editing outcomes.
HEK293T cells are derived from human embryonic kidney cells transformed with adenovirus 5 DNA and stably express the SV40 large T antigen, which permits episomal replication of plasmids containing the SV40 origin of replication. This feature enables high-level transient protein expression and efficient viral production, making HEK293T a workhorse for recombinant protein studies and lentiviral packaging. Their robust growth and transfectability offer a reliable background for functional knockout studies.
EIF3J is a core subunit of the eIF3 complex that stabilizes the interaction between the 40S ribosomal subunit and initiation factors, and facilitates recruitment of the ternary complex and mRNA. Its activity is regulated by mTORC1 signaling and the MAPK pathway, operating downstream of MYC to control global protein synthesis and the translation of specific oncogenes like MYC and CCND1. EIF3J interacts with eIF3 subunits (eIF3A, eIF3B), the 40S ribosome, eIF2, eIF4G, and DHX29 helicase, and contributes to IRES-mediated translation initiation.
In the HEK293T context, EIF3J knockout disrupts basal translation initiation, leading to reduced global protein synthesis and altered expression of proteins reliant on eIF3 complex integrity. This model enables dissection of mTOR-dependent translation control and IRES-mediated mechanisms, and is useful for complementation studies to map functional domains of EIF3J. Given its relevance to cancer and neurodegenerative diseases, this model supports research into oncogenic signaling and translational dysregulation.
Applications include puromycin incorporation assays to measure global translation rates, polysome profiling and ribosome footprinting to assess ribosome occupancy, and Western blotting for eIF3J and its downstream targets (MYC, CCND1). Cell proliferation, colony formation, and flow cytometry for cell cycle analysis enable functional assessment of EIF3J in growth control. RT-qPCR can monitor transcriptional changes of translationally regulated genes, and these cells are suitable for drug target validation and functional genomics screens. For further information, please contact Ascent Research.
