The BROX Knockout HAP1 Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout cell population designed for targeted disruption of the BROX gene in human cells. This product provides a mixed population of HAP1 cells carrying heterogeneous knockout alleles generated by CRISPR/Cas9-mediated gene disruption, enabling loss-of-function studies without clonal isolation. As a polyclonal knockout pool, it preserves genetic diversity while eliminating functional BROX protein, offering a robust model for investigating the role of this ESCRT-associated factor in membrane abscission processes.
The HAP1 cell line is a near-haploid human chronic myeloid leukemia (CML) cell line derived from the KBM-7 line. Its near-haploid karyotype, with only one copy of most chromosomes, facilitates straightforward gene targeting and phenotypic analysis, as a single genetic alteration can unmask recessive phenotypes. HAP1 cells are widely employed as a genetic screening model in cancer biology due to their rapid growth, ease of culture, and compatibility with various functional genomics approaches, making them an ideal chassis for ESCRT pathway interrogation.
BROX encodes an ESCRT-associated protein that directly binds CHMP4B, a core component of the ESCRT-III complex, via its BRO1 domain, and is critical for membrane scission events at the midbody during cytokinesis and at sites of viral budding. BROX interacts with ALIX (PDCD6IP) and the ESCRT-III complex, and its function is regulated by mitotic kinase signaling and ESCRT-III assembly dynamics. Mechanistically, BROX facilitates ESCRT-III filament remodeling and disassembly, acting downstream of CEP55 and MKLP1 at the midbody, and contributes to the final abscission step that separates daughter cells or releases enveloped viruses. It interacts with CHMP2A and VPS4 to coordinate membrane fission.
Given the near-haploid nature of HAP1 cells, disruption of BROX is expected to fully abolish BROX-dependent functions, leading to pronounced cytokinesis defects such as failed abscission, multinucleation, and genomic instability. This model is particularly valuable for studying the ESCRT pathway’s role in cancer cell division, where abscission failure can promote aneuploidy and tumor progression. BROX-deficient HAP1 cells also serve as a platform to examine host factors required for viral budding, with relevance to enveloped virus infections.
Applications include functional genomics of the ESCRT pathway, cytokinesis failure studies, viral budding assays, and drug screening for cytokinesis inhibitors. Representative assays enabled by these cells encompass western blotting for BROX and ESCRT markers, immunofluorescence staining of midbody and abscission markers, flow cytometric analysis of cell cycle and multinucleation, viral budding assays, proliferation assays, and RNA-seq profiling of ESCRT pathway targets. Researchers can leverage BROX knockout HAP1 polyclonal cells to dissect ESCRT-III dynamics and identify novel regulators or small molecules that modulate abscission. For further technical details or customized options, please contact Ascent Research.
