The GTPBP3 Knockout HAP1 Polyclonal Cells product provides a CRISPR/Cas9-edited polyclonal knockout cell population targeting the GTPBP3 gene in the near-haploid human HAP1 cell line. This polyclonal model, generated via CRISPR/Cas9-mediated gene disruption, is designed for studying the loss-of-function effects of GTPBP3, a mitochondrial GTPase essential for mitochondrial translation and oxidative phosphorylation. The knockout population offers a robust tool for investigating the molecular consequences of disrupted mitochondrial tRNA modification without the need for clonal isolation.
HAP1 is a near-haploid human cell line derived from the KBM-7 chronic myeloid leukemia patient cell line, exhibiting an adherent, fibroblast-like morphology. The near-haploid karyotype simplifies genetic analysis and knockout studies, as gene disruptions typically result in complete loss of function without compensation from a second allele. This characteristic has made HAP1 cells particularly valuable for genome-wide knockout screens and functional genomics studies.
GTPBP3, in complex with MTO1, catalyzes the 5-taurinomethylation of mitochondrial tRNAs, a critical modification for accurate mitochondrial translation. This post-transcriptional modification is essential for proper decoding during mitochondrial protein synthesis, directly influencing the assembly and activity of oxidative phosphorylation (OXPHOS) complexes I?CV. Upstream regulators such as PGC-1??, NRF1, and TFAM orchestrate mitochondrial biogenesis and function, while GTPBP3 interacts with mitochondrial small ribosomal subunits and tRNA-modifying enzyme components, including MRM2, to ensure translation fidelity. Disruption of GTPBP3 abrogates this modification pathway, leading to defective mitochondrial protein synthesis and impaired respiratory chain function.
In the HAP1 near-haploid background, GTPBP3 knockout directly abolishes its function, providing a clear cellular model for mitochondrial translation defects. The loss of GTPBP3-dependent tRNA modification results in compromised synthesis of mtDNA-encoded OXPHOS subunits, which can be quantified using assays such as Western blotting for OXPHOS components or puromycin-based mitochondrial protein synthesis measurements. The near-haploid nature ensures a homogeneous genetic disruption, reducing variability and enhancing reproducibility in phenotypic analyses, including assessment of mitochondrial respiration via Seahorse analysis and lactate production as a marker of metabolic shift.
Key research applications include modeling combined oxidative phosphorylation deficiency 23 and Leigh syndrome, dissecting the molecular mechanisms of mitochondrial tRNA modification, and evaluating therapeutic interventions for mitochondrial disorders. Typical assays involve Western blotting for OXPHOS subunits, Seahorse mitochondrial respiration assay, mitochondrial protein synthesis assay (SUnSET/puromycin), tRNA modification analysis by LC-MS/MS, immunofluorescence for mitochondrial morphology, and lactate production assay. This polyclonal knockout cell population serves as a reliable platform for screening small molecules, genetic modifiers, or CRISPR-based rescue strategies aimed at restoring mitochondrial function. For additional technical details and batch-specific information, please contact Ascent Research.
