The BRK1 Knockout HEK293T Polyclonal Cells are a CRISPR/Cas9-edited polyclonal cell population derived from HEK293T human embryonic kidney epithelial cells. This product provides a loss-of-function model with targeted disruption of the BRK1 gene, which encodes an essential subunit of the WAVE regulatory complex (WRC). The polyclonal knockout cells offer a robust reduction in BRK1 protein expression, enabling functional studies of the WRC?CArp2/3 signaling axis. These cells are suitable for rescue experiments, high-throughput screening, and biochemical analyses requiring a knockout context in a well-characterized host background.
HEK293T cells are a female human embryonic kidney epithelial line immortalized by adenovirus 5 DNA and SV40 large T antigen expression. This immortalization confers high transfection efficiency, robust proliferation, and the ability to support episomal replication of plasmids containing the SV40 origin. These features make HEK293T a preferred host for recombinant protein production, lentiviral packaging, and CRISPR screens. The adherent monolayer morphology and well-characterized growth simplify imaging-based cytoskeletal assays and quantitative biochemical analyses.
BRK1 (HSPC300) is an obligate subunit of the pentameric WAVE regulatory complex (WRC) that also comprises CYFIP1, NCKAP1, ABI2, and WASF2 (WAVE2). The WRC functions downstream of activated Rac1 GTPase, transducing signals from receptor tyrosine kinases (e.g., PDGFR, EGFR) and phosphoinositides to the Arp2/3 complex, the primary nucleator of branched actin filaments. Upon Rac1?CGTP binding to CYFIP1, the WRC undergoes a conformational change that releases autoinhibition, allowing WAVE2 to activate Arp2/3. This activation drives actin polymerization at the cell leading edge, generating lamellipodia and promoting cell migration. BRK1 knockout disrupts WRC assembly, uncoupling Rac1 signaling from Arp2/3-mediated actin nucleation and impairing lamellipodia formation. Interacting partners include CYFIP1, which binds active Rac1, and ABI2, which stabilizes the complex; the pathway is further modulated by Rho family GTPases.
In HEK293T cells, which exhibit robust actin dynamics and high transfection efficiency, BRK1 knockout provides a defined model to dissect WRC function. The knockout yields quantifiable defects in cell morphology, reduced migration in wound healing and transwell assays, and impaired lamellipodia formation. The polyclonal population mimics natural cellular heterogeneity, enabling robust phenotypic characterization. This model supports rescue experiments with wild-type or mutant BRK1 to probe structure-function relationships. SV40 large T antigen-driven plasmid amplification also facilitates additional CRISPR modifications for double-knockout studies. Thus, these cells serve as a versatile platform for investigating Rac1-WRC-Arp2/3 signaling and cell motility.
Typical applications include western blotting to assess BRK1 and WRC subunit levels, pyrene actin polymerization assays, scratch wound healing and transwell migration to quantify motility, and phalloidin staining with live-cell imaging to visualize lamellipodial dynamics. The cells are compatible with Rac1 activation pull-downs to probe upstream signaling integrity. This knockout model is suitable for high-content screening of small-molecule modulators of the Rac1?CWRC?CArp2/3 axis and genome-wide CRISPR screens for synthetic lethality. The polyclonal format supports cost-effective large-scale studies without clonal isolation. For detailed protocols and technical support, please contact Ascent Research.
