The HPS3 Knockout HAP1 Polyclonal Cells are a pool of CRISPR/Cas9-edited polyclonal knockout cells generated through disruption of the HPS3 gene in the HAP1 human near-haploid fibroblast-like cell line. This population consists of cells carrying diverse loss-of-function modifications at the endogenous HPS3 locus, offering a robust model for investigating HPS3-dependent processes. The polyclonal format preserves genetic diversity while ensuring target-gene disruption, facilitating phenotypic studies in a tractable system. This knockout model serves as a versatile platform for functional genomics and disease research.
The HAP1 cell line, derived from a patient with chronic myeloid leukemia, is a human near-haploid fibroblast-like cell line widely used for genetic screening and gene function studies. Its near-haploid karyotype facilitates efficient CRISPR/Cas9 editing and straightforward interpretation of gene knockout effects. HAP1 cells are robust and easily cultured, enabling reproducible functional assays. The near-haploid state makes them particularly suited for arrayed screening approaches.
HPS3 is a subunit of the biogenesis of lysosome-related organelles complex-2 (BLOC-2), interacting with HPS5 and HPS6 to facilitate cargo delivery to melanosomes and platelet dense granules. Its expression is regulated by MITF and SOX10, and it promotes the trafficking of melanosomal proteins TYR and TYRP1. Downstream, it mediates platelet dense granule secretion and lysosomal enzyme sorting. BLOC-2 cooperates with BLOC-1, the AP-3 complex, and Rab GTPases, and HPS3 deficiency disrupts organelle biogenesis, resulting in Hermansky-Pudlak syndrome type 3.
The near-haploid nature of HAP1 cells ensures that HPS3 disruption directly yields functional consequences without allelic redundancy, offering a clear model for parsing BLOC-2 functions. This polyclonal knockout population is particularly valuable for dissecting melanosome and platelet dense granule maturation pathways, as it avoids clonal selection bias and captures a spectrum of loss-of-function effects. This makes it an excellent tool for investigating the molecular mechanisms underlying Hermansky-Pudlak syndrome and related disorders.
Typical applications include disease modeling for Hermansky-Pudlak syndrome type 3, oculocutaneous albinism, and bleeding diathesis, as well as melanosome trafficking studies and lysosomal enzyme assays. Representative assays include western blotting to confirm HPS3 loss, immunofluorescence for melanosome markers such as TYRP1, flow cytometry for CD63, platelet aggregation studies, and melanin quantification. This polyclonal knockout resource is also amenable to suppressor screens and drug discovery efforts. For further technical specifications, contact Ascent Research.
