The ASF1B Knockout HEK293T Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population engineered for loss-of-function studies of the ASF1B gene. This model utilizes CRISPR/Cas9-mediated gene disruption to generate a heterogeneous pool of HEK293T cells carrying targeted genome modifications that ablate ASF1B protein expression. The polyclonal format avoids clonal selection artifacts and provides a robust, population-level tool for interrogating ASF1B function in chromatin biology and oncogenic processes.
The host HEK293T cell line is a widely adopted human embryonic kidney epithelial model, derived from HEK293 cells transformed with sheared adenovirus 5 DNA, and it stably expresses the SV40 large T antigen for episomal plasmid replication. HEK293T cells are favored for high-efficiency transfection, recombinant protein production, lentiviral packaging, and CRISPR-based genetic screens. The ASF1B knockout in this background offers a physiologically relevant system for studying cell cycle-dependent chromatin assembly and DNA replication dynamics.
ASF1B encodes a dedicated histone chaperone that specifically delivers H3.1-H4 dimers to the CAF-1 complex at replication forks, facilitating nucleosome assembly onto newly synthesized DNA. Transcriptionally activated by E2F1 and E2F2 during G1/S progression, ASF1B directly interacts with histones H3.1 and H4, CAF-1 subunits CHAF1A and CHAF1B, MCM2, and the TLK1/TLK2 kinases. Downstream, ASF1B promotes replication fork stability, RAD51-dependent homologous recombination repair, and the expression of cyclins E1 and A2, integrating chromatin assembly with cell cycle advance and DNA damage responses.
In the highly proliferative HEK293T background, ASF1B disruption offers a precise model to dissect replication-coupled chromatin assembly and its coordination with cell cycle checkpoints. This knockout population is particularly valuable for examining G1/S transition dynamics, replication stress responses, and the functional interplay between ASF1B and tumor suppressor pathways, given ASF1B??s overexpression in cancers such as breast, lung, and hepatocellular carcinoma. The polyclonal nature preserves phenotypic diversity, enabling population-level analyses of ASF1B-dependent proliferation and genome maintenance.
Researchers can employ these knockout cells for co-immunoprecipitation experiments to probe ASF1B interactions with CAF-1 and histone H3.1, or perform EdU incorporation and ??H2AX Western blotting to assess replication stress. Flow cytometry cell cycle profiling and RNA-seq transcriptomic analyses can define ASF1B-driven gene networks. Additionally, the polyclonal format supports high-throughput synthetic lethal screens to identify ASF1B dependencies in cancer. For further information and ordering details, please contact Ascent Research.
