The ATOSB Knockout HEK293T Polyclonal Cells product provides a CRISPR/Cas9-edited polyclonal knockout cell population in which the ATOSB gene is disrupted, resulting in a loss-of-function model suitable for dissecting ATOSB-dependent cellular processes. This polyclonal format preserves the genetic diversity of the edited pool, enabling robust assessment of gene function without clonal selection biases. Researchers can employ these cells to investigate the role of ATOSB in DNA damage signaling and genome maintenance, leveraging the genetic tractability of HEK293T cells.
The host cell line, HEK293T, is a derivative of the human embryonic kidney HEK293 cell line that constitutively expresses the SV40 large T antigen, permitting episomal replication of plasmids bearing the SV40 origin of replication. These adherent epithelial cells are widely utilized for transient and stable protein expression, viral packaging, and nucleic acid transfection experiments. Their ease of culture and high transfection efficiency make HEK293T cells an ideal platform for generating knockout models to study fundamental cellular mechanisms, including DNA damage responses and cell cycle control.
ATOSB is implicated in the ATR-dependent DNA damage checkpoint, acting as a mediator of replication stress signaling. Mechanistically, ATOSB is thought to facilitate ATR recruitment or activation at stalled replication forks, promoting CHK1 phosphorylation on Ser345 and subsequent cell cycle arrest. The protein interacts with key components of the ATR pathway, including ATR, ATRIP, RPA70, TOPBP1, and Claspin, and functions downstream of RPA-coated single-stranded DNA and upstream of effectors such as CHK1, CDC25A, and CDK2. Disruption of ATOSB compromises the cellular response to replication stress, leading to impaired checkpoint activation and elevated genomic instability.
In the HEK293T context, ATOSB knockout provides a defined genetic background to examine ATR signaling dynamics and replication fork stability. Given the line??s embryonic kidney origin and robust proliferation, it is particularly amenable to studying cell cycle checkpoint defects and DNA repair deficiencies. Loss of ATOSB in these cells is expected to phenocopy aspects of replication stress syndromes, allowing detailed biochemical and functional analyses of the ATR-CHK1 axis and its downstream consequences on cell cycle progression and survival under genotoxic conditions.
These polyclonal knockout cells are suited for a wide range of research applications, including interrogation of replication stress responses, validation of ATR pathway targets, and assessment of genome integrity. Representative experimental approaches include western blotting for phospho-CHK1 (Ser345) to monitor ATR activity, flow cytometry for cell cycle distribution, comet assays to quantify DNA damage, and immunofluorescence microscopy for ??-H2AX foci formation. Additional assays such as clonogenic survival after exposure to genotoxic agents, DNA fiber assays to evaluate replication fork dynamics, and drug sensitivity testing with ATR inhibitors further expand the utility of this model. For further details, please contact Ascent Research.
