The BCKDK Knockout A-549 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the A-549 human lung adenocarcinoma cell line. This product targets the BCKDK gene (branched-chain ketoacid dehydrogenase kinase), creating a loss-of-function model for studying branched-chain amino acid (BCAA) catabolism and associated signaling networks. The polyclonal format provides a heterogeneous pool of edited cells, enabling robust and reproducible functional studies without clonal selection artifacts.
The parental A-549 cell line is an adherent epithelial cell line originally isolated from a 58-year-old male with lung adenocarcinoma. This well-characterized model harbors a KRAS G12S mutation and STK11/LKB1 loss, making it a widely used system for non-small cell lung cancer (NSCLC) research, particularly for investigating lung adenocarcinoma biology, metabolic adaptations, and drug response mechanisms.
BCKDK functions as a key negative regulator of the branched-chain ??-ketoacid dehydrogenase complex (BCKDC) by phosphorylating the E1?? subunit BCKDHA at Ser293 and Ser303, leading to complex inactivation. In this knockout model, CRISPR/Cas9-mediated disruption of BCKDK eliminates this inhibitory phosphorylation, resulting in constitutive BCKDC activity and accelerated catabolism of the branched-chain amino acids leucine, isoleucine, and valine. This metabolic shift directly reduces intracellular BCAA levels, which are sensed by mTORC1 through Sestrin2-dependent Rag GTPase regulation, thereby limiting mTORC1 signaling and downstream phosphorylation of S6K and S6. BCKDK activity is regulated by the phosphatase PPM1K, which dephosphorylates BCKDHA, and is transcriptionally controlled by PPAR?? agonists and insulin. The resulting BCAA dysregulation also impacts the TCA cycle via altered branched-chain ??-keto acid entry and intersects with PPAR signaling.
In the A-549 adenocarcinoma background, the coexistence of KRAS G12S and STK11/LKB1 loss creates a metabolic context highly dependent on mTORC1 signaling and amino acid availability. This BCKDK knockout model allows researchers to investigate how enhanced BCAA catabolism alters metabolic reprogramming in NSCLC, affecting cell proliferation and survival. Furthermore, because BCKDK deficiency is linked to neurodevelopmental disorders such as autism and intellectual disability, this model provides a tractable system to study the cellular consequences of BCKDC overactivation, including mitochondrial stress and altered energy homeostasis.
Typical experiments include western blotting for phospho-BCKDHA (Ser293) and total BCKDK protein, BCKDC enzymatic activity assays, and LC-MS-based quantification of intracellular BCAA and BCKA pools. mTORC1 pathway activity is frequently measured by phospho-S6K and phospho-S6 levels. Functional assays such as MTT or BrdU proliferation tests, apoptosis detection, and RT-qPCR profiling of BCAA metabolic enzymes provide phenotypic characterization. This polyclonal knockout population is well-suited for drug sensitivity screens under leucine-restricted or -replete conditions and for validating BCKDK as a therapeutic target in lung adenocarcinoma. For additional information about this knockout model, please contact Ascent Research.
