GTPBP3 Knockout Jurkat Polyclonal Cells are a CRISPR/Cas9-mediated gene-edited cell pool derived from the Jurkat human T-lymphoblast line. This polyclonal population contains heterogeneous on-target disruptions at the GTPBP3 locus, providing a loss-of-function model for studying mitochondrial tRNA modification and its role in oxidative phosphorylation. The use of a polyclonal format avoids clonal selection biases and permits population-level functional analyses.
Jurkat cells are an immortalized T-lymphocyte line originally isolated from a patient with acute T-cell leukemia. They serve as a classic suspension cell model for investigating T-cell receptor signaling, apoptosis, and immune activation. Their well-characterized growth requirements and susceptibility to genetic manipulation make them suitable for generating knockout derivatives.
GTPBP3 encodes a GTPase that, together with MTO1, catalyzes the taurinomethylation of wobble uridine at position 34 in a subset of mitochondrial tRNAs, including mt-tRNA-Phe, mt-tRNA-Lys, mt-tRNA-Glu, mt-tRNA-Gln, mt-tRNA-Leu, and mt-tRNA-Trp. This modification ensures accurate codon-anticodon pairing during mitochondrial translation. The GTPBP3 gene is transcriptionally regulated by NRF1, TFAM, and PPARGC1A, linking mitochondrial biogenesis signals to the protein synthesis machinery. Disruption of GTPBP3 impairs the translation of mtDNA-encoded OXPHOS subunits, leading to reduced activity of respiratory complexes I, III, IV, and V.
In the Jurkat background, GTPBP3 knockout provides a relevant model to examine how mitochondrial tRNA defects affect T-cell biology. Although Jurkat cells exhibit high glycolytic rates, they retain active oxidative phosphorylation, and mitochondrial dysfunction can influence proliferation, survival, and TCR-mediated signaling. This system is pertinent to studies of combined oxidative phosphorylation deficiency 23 (COXPD23), a disorder caused by GTPBP3 mutations, and to broader investigations of mitochondrial pathology in leukemogenesis and immune function.
These polyclonal knockout cells enable a wide range of experimental approaches. Mitochondrial translation can be monitored by pulse-labeling with 35S-methionine in the presence of emetine, and steady-state OXPHOS protein levels can be determined by Western blotting. Oxygen consumption rates are assessable via Seahorse analysis, while a galactose challenge assay evaluates dependence on oxidative phosphorylation. Defects in tRNA modification can be detected by Northern blot or mass spectrometry, and mitochondrial membrane potential can be measured by flow cytometry. The model is thus suited for mechanistic studies of mitochondrial translation, disease modeling for COXPD23, and screens for compounds that rescue respiratory defects. For additional information, contact Ascent Research.
