The BLOC1S4 Knockout HAP1 Polyclonal Cells represent a CRISPR/Cas9-edited polyclonal knockout cell population in which the gene encoding BLOC1S4 has been disrupted. This product provides a loss-of-function model for investigating the BLOC-1 complex subunit BLOC1S4, essential for endosomal trafficking and lysosome-related organelle biogenesis. The polyclonal format offers a heterogeneous knockout pool, ideal for studying gene function without clonal selection bias, and is suitable for functional genomics, pathway analysis, and phenotypic screening.
These cells are derived from the HAP1 cell line, a near-haploid human cell line originally isolated from KBM-7 chronic myeloid leukemia cells. HAP1 cells exhibit adherent growth and contain a single copy of most chromosomes, making them an excellent host for knockout studies by eliminating the complications of diploid gene dosage. Their genetic stability and haploid nature facilitate clear genotype?Cphenotype relationships, particularly for recessive mutations, and they are widely used in genetic screens, mutagenesis studies, and CRISPR-based functional validation.
BLOC1S4 encodes a critical subunit of the biogenesis of lysosome-related organelles complex 1 (BLOC-1), which mediates cargo sorting from early endosomes to lysosome-related organelles such as melanosomes and platelet dense granules. BLOC1S4 forms a complex with BLOC1S1, BLOC1S2, BLOC1S3, BLOC1S5, and BLOC1S6, and interacts with the adaptor protein complex AP-3. The BLOC-1 complex functions downstream of the MITF transcription factor, which regulates its expression, and is essential for proper lysosomal enzyme secretion and autophagy flux. Loss of BLOC1S4 disrupts LAMP1-positive organelle distribution and impairs autophagic degradation, as evidenced by accumulation of LC3-II and p62. Thus, BLOC1S4 is a key node connecting endosomal sorting, lysosomal biogenesis, and autophagy.
Disruption of BLOC1S4 in HAP1 cells creates a powerful model for studying Hermansky-Pudlak syndrome, a disorder characterized by defects in lysosome-related organelle biogenesis. The near-haploid background of HAP1 ensures that knockout effects are not masked by a second functional allele, enabling robust phenotypic assessment. This model recapitulates trafficking deficiencies observed in patient cells, including impaired melanosome maturation and platelet dense granule formation. Additionally, it serves as a platform for investigating lysosomal storage disorders and autophagy-related pathologies, providing insights into how BLOC-1 complex integrity influences cellular clearance mechanisms.
Researchers can employ these BLOC1S4 knockout cells in diverse applications including autophagy flux assays using LC3-II and p62 western blotting, immunofluorescence microscopy for LAMP1/LAMP2 to assess lysosomal distribution, and lysosomal pH measurements. Co-immunoprecipitation experiments can probe BLOC-1 complex assembly and interactions with AP-3. This polyclonal knockout model is particularly suitable for phenotypic screens, drug discovery targeting lysosomal pathways, and studies on endosomal trafficking. For further details or custom inquiries, please contact Ascent Research.
