DBT Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population designed to disrupt the DBT gene in the Raji human B lymphocyte cell line. DBT encodes the E2 subunit (dihydrolipoamide branched-chain transacylase) of the branched-chain ??-keto acid dehydrogenase complex (BCKDC), a key enzyme in the catabolism of branched-chain amino acids (BCAAs: leucine, isoleucine, valine). This gene-disrupted polyclonal pool provides a loss-of-function model to investigate DBT-dependent metabolic pathways without selection of a single clonal isolate, thereby preserving population-level heterogeneity for robust functional studies.
Raji cells are an Epstein-Barr virus (EBV)-positive Burkitt’s lymphoma B lymphocyte line originally derived from a Nigerian patient. As a cancerous B cell model, Raji cells exhibit characteristic features of aggressive lymphoma, including rapid proliferation and distinct surface marker expression (e.g., CD19, CD20). They are widely used in immunology, oncology, and infectious disease research, particularly for studying EBV-mediated lymphomagenesis and B cell receptor signaling. Their metabolic profile, including reliance on oxidative phosphorylation and glycolysis, makes them a relevant host for investigating metabolic enzyme perturbations.
At the molecular level, DBT forms the core of the BCKDC along with the E1?? (BCKDHA), E1?? (BCKDHB), and E3 (DLD) subunits. The E2 subunit uses lipoic acid as a covalently attached cofactor to transfer acyl groups from the E1 decarboxylation products to coenzyme A, generating isovaleryl-CoA, isobutyryl-CoA, and 2-methylbutyryl-CoA. These intermediates enter downstream degradation pathways, ultimately feeding into the TCA cycle as acetyl-CoA and succinyl-CoA. The BCKDC complex is tightly regulated by reversible phosphorylation: BCKDK inactivates the complex by phosphorylating the E1?? subunit, while PPM1K activates it by dephosphorylation. Additional regulation occurs through insulin, mTORC1, PPARGC1A, and the NADH/NAD+ and CoA/acyl-CoA ratios. Disruption of DBT therefore impairs the entire BCKDC assembly and catalytic function, leading to accumulation of branched-chain ??-keto acids and altered mitochondrial metabolite pools.
In the Raji B lymphocyte context, DBT knockout offers a unique platform to study the intersection of BCAA metabolism and lymphomagenesis. BCAAs serve not only as energy substrates but also as signaling molecules that modulate mTORC1 activity and protein synthesis. Loss of DBT function is expected to dysregulate BCAA catabolism, potentially shifting metabolic dependency, affecting redox balance, and impacting cell proliferation and survival. This model is particularly relevant to understanding metabolic vulnerabilities in aggressive B cell lymphomas and to modeling inherited metabolic disorders such as maple syrup urine disease type II, which results from mutations in DBT. By employing techniques such as LC-MS metabolomics, Seahorse mitochondrial stress tests, and BCKDC enzymatic assays, researchers can elucidate how DBT loss remodels the metabolic landscape of lymphoma cells.
Typical research applications for this product include functional analysis of DBT in mitochondrial metabolism, investigation of BCAA catabolism in B cell malignancies, modeling of branched-chain ketoaciduria, drug screening for modulators of BCKDC activity, and mapping of metabolic dependencies in cancer. The polyclonal knockout pool is compatible with standard assays including Western blotting, RT-qPCR, Sanger sequencing, proliferation and apoptosis assays, and flow cytometry for B cell markers. For additional information, validation data, or technical support, please contact Ascent Research.
