The HERC4 Knockout HeLa Polyclonal Cells comprise a CRISPR/Cas9-edited polyclonal knockout cell population in which the HERC4 gene has been disrupted to generate a loss-of-function model. This polyclonal format provides a heterogeneous pool of edited cells, enabling robust functional studies without single-cell clonal isolation. The product is designed for investigating HERC4-dependent cellular processes, particularly its role as an E3 ubiquitin-protein ligase in immune signaling and proteasomal degradation pathways.
The HeLa host cell line is an immortalized cervical adenocarcinoma epithelial cell line derived from a biopsy of Henrietta Lacks in 1951. These cells contain integrated human papillomavirus type 18 (HPV-18) sequences and are widely used as a model system for cancer biology, virology, and signal transduction research. The HeLa background provides a well-characterized platform for studying gene function in the context of cervical cancer and host?Cpathogen interactions.
HERC4 encodes an E3 ubiquitin ligase that mediates K48-linked ubiquitination of TAK1 (MAP3K7), targeting it for proteasomal degradation. This activity functions downstream of the RIG-I and MDA5 pattern recognition receptors, which are activated by viral double-stranded RNA. Upon viral infection, the adaptor protein MAVS transduces signals to TRAF3 and the kinases TBK1 and IKK??, leading to phosphorylation and activation of the transcription factors IRF3 and IRF7. In parallel, TAK1, in complex with TAB2, activates the IKK complex (IKK??/IKK??), resulting in NF-??B p65/p50 nuclear translocation and induction of proinflammatory cytokines and type I interferons such as IFN-??. HERC4 interacts with TAK1 and the E2 enzyme UBE2L3, and its activity is counteracted by deubiquitinases like CYLD and A20. By promoting TAK1 degradation, HERC4 attenuates both NF-??B and IRF3 signaling, thereby suppressing antiviral gene expression and cytokine production.
In the HeLa cell context, disruption of HERC4 is expected to stabilize TAK1 and enhance signal transduction through the RIG-I/MDA5 pathway, leading to increased activation of NF-??B and IRF3. This makes the knockout model particularly valuable for dissecting the regulatory mechanisms of innate immune responses in a cervical cancer background. Given that HeLa cells harbor HPV oncoproteins, which interfere with innate immune signaling, the HERC4 knockout provides a tool to explore how E3 ligase activity intersects with viral oncogenesis and host defense. Moreover, because HERC4 modulates ubiquitin-dependent degradation, its loss may influence cancer-related signaling networks that rely on NF-??B and ubiquitin-proteasome system components.
Researchers can employ this polyclonal knockout population in a variety of experimental assays. Western blotting and RT-qPCR can be used to measure changes in phosphorylated TAK1, p65, and IRF3, as well as expression of downstream targets such as IFN-??, ISG15, and IL-6. Viral infection assays with influenza virus or other pathogens can assess the impact of HERC4 loss on viral replication and host response. Dual-luciferase reporter assays enable quantitative monitoring of NF-??B and IRF3 activity, while co-immunoprecipitation and ubiquitination assays allow direct interrogation of HERC4?CTAK1 interactions and K48-linked ubiquitin chain formation. Cell viability assays can further evaluate the role of HERC4 in proliferation and survival. For additional information or technical support, please contact Ascent Research.
