The DPYS Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the HAP1 human haploid cell line, designed to disrupt the DPYS locus. This product contains a heterogeneous pool of edited cells, each carrying independent gene-disrupting events across the DPYS target region, enabling loss-of-function studies without clonal isolation. The polyclonal format provides robust population-level gene disruption, suitable for pooled functional assays and high-throughput screening applications.
HAP1 cells are a near-haploid human adherent fibroblast-like cell line originally derived from the KBM-7 chronic myeloid leukemia cell line. Their haploid karyotype??containing a single set of chromosomes??facilitates efficient and complete gene disruption following CRISPR/Cas9 editing, as only one allele needs to be targeted. This feature makes HAP1 an exceptional host for functional genomics, allowing unambiguous genotype?Cphenotype correlations and minimizing complications from heterozygous or compound effects.
The DPYS gene encodes dihydropyrimidinase, a zinc-dependent homotetrameric enzyme that catalyzes the second step of pyrimidine catabolism: the hydrolysis of 5,6-dihydrouracil and 5,6-dihydrothymine to N-carbamyl-??-alanine and N-carbamyl-??-aminoisobutyrate, respectively. DPYS functions downstream of DPYD (dihydropyrimidine dehydrogenase) and upstream of UPB1 (??-ureidopropionase), which completes the pathway to produce ??-alanine and ??-aminoisobutyric acid. Disruption of DPYS therefore blocks the conversion of dihydropyrimidines, leading to their accumulation and a reduction of downstream metabolites. Although upstream regulatory mechanisms are not well defined, p53 has been suggested as a possible regulator.
In the HAP1 haploid background, DPYS knockout provides a clean, simplified system for dissecting pyrimidine degradation and its intersection with drug metabolism. The loss of dihydropyrimidinase activity mimics dihydropyrimidinase deficiency, an inborn error of metabolism associated with dihydropyrimidinuria and variable neurological symptoms. Moreover, this model is instrumental for investigating fluoropyrimidine toxicity (e.g., 5-fluorouracil, capecitabine), because DPYS deficiency can impair the detoxification pathway, leading to severe adverse drug reactions.
This knockout cell product is suited for a broad range of research applications, including metabolomic profiling of dihydropyrimidine intermediates by LC-MS, cytotoxicity assays for fluoropyrimidine sensitivity, functional genomics screens to identify modulators of pyrimidine degradation, and validation of DPYS protein and mRNA expression by Western blot and RT-qPCR. The polyclonal pool is also amenable to cell proliferation assays and pooled CRISPR-modifier screens. For additional technical details or to discuss custom configurations, please contact Ascent Research.
