The HEXA Knockout HAP1 Polyclonal Cells represent a CRISPR/Cas9-mediated gene disruption population designed to eliminate functional expression of the HEXA gene in the near-haploid HAP1 human cell line. This polyclonal product consists of a heterogeneous pool of cells carrying diverse targeted disruptions within the HEXA locus, generated by non-homologous end joining repair after Cas9 cleavage. As a polyclonal knockout population, it is particularly suited for pooled functional screens, population-level phenotype analyses, and studies where clonal homogeneity is not required. The loss of HEXA function abolishes beta-hexosaminidase A (HexA) enzymatic activity, establishing a powerful loss-of-function model for investigating lysosomal GM2 ganglioside catabolism.
The host HAP1 cell line is a fibroblast-like, near-haploid human cell model originally derived from the KBM-7 chronic myelogenous leukemia line. Its haploid karyotype??approximately 25 chromosomes??facilitates efficient CRISPR-mediated knockout because only a single allele must be disrupted to produce a null phenotype in most genes, thereby avoiding complications from heterozygous editing. HAP1 cells retain many normal signaling networks and metabolic pathways, making them a versatile platform for genetic dissection of lysosomal function, sphingolipid metabolism, and glycosphingolipid storage disorders. Moreover, their rapid growth and ease of transfection enable robust experimental workflows, including high-throughput arrayed screening.
HEXA encodes the alpha subunit of the heterodimeric lysosomal enzyme beta-hexosaminidase A. In conjunction with the beta subunit (HEXB) and the GM2 activator protein (GM2A), HexA catalyzes the terminal hydrolytic step that converts GM2 ganglioside to GM3 ganglioside within the lysosomal lumen. This reaction is a critical gateway in ganglioside degradation and overall sphingolipid turnover. Upstream, expression of HEXA and many lysosomal genes is transcriptionally regulated by TFEB, a master controller of lysosomal biogenesis, which itself is inhibited by mTORC1 signaling under nutrient-replete conditions. Disruption of HEXA, therefore, uncouples this regulatory axis, causing accumulation of GM2 ganglioside and its precursors, mimicking the molecular pathology of Tay-Sachs disease.
In the HAP1 genetic background, HEXA knockout creates an experimentally tractable model that faithfully recapitulates the core biochemical defect of GM2 gangliosidosis. The near-haploid state enhances phenotype penetrance and facilitates quantitative linkage of genotype to lysosomal phenotype using standard biochemical and imaging readouts. This model allows acute interrogation of TFEB?CmTORC1 interplay in controlling lysosomal enzyme expression, as well as the role of compensatory glycosphingolipid pathways. Moreover, the cell line??s chronic myelogenous leukemia origin introduces an interesting context for studying how sphingolipid metabolism interfaces with oncogenic signaling, though primary applications center on lysosomal storage disorder research.
Researchers can employ these HEXA knockout cells in a broad array of experimental paradigms to dissect sphingolipid metabolism and evaluate therapeutic strategies for lysosomal storage diseases. Representative assays include fluorometric or colorimetric beta-hexosaminidase activity measurements to confirm loss of enzyme function, immunofluorescence staining for GM2 ganglioside accumulation, and western blot analysis for residual HEXA protein. RT-qPCR enables quantification of HEXA transcript levels, while lysosomal pH probes and electron microscopy assess lysosomal swelling and storage burden. The cells are also ideal for high-throughput chemical or genetic screens aimed at identifying molecules that bypass HexA deficiency or enhance residual lysosomal function. For further information regarding this product, please contact Ascent Research.
