The APOBEC3G Knockout A-549 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the A-549 human lung adenocarcinoma cell line. These cells carry a targeted disruption of the APOBEC3G gene, abolishing functional expression of the APOBEC3G protein. This polyclonal knockout pool provides a robust loss-of-function model for investigating the roles of APOBEC3G in innate antiviral immunity and APOBEC-mediated mutagenesis. The use of a polyclonal population ensures representation of diverse editing events while avoiding clonal artifacts.
The parental A-549 cell line was originally established from the lung carcinoma tissue of a 58-year-old male. These epithelial cells are hypodiploid, adherent, and harbor wild-type p53. A-549 serves as a widely used model for studying lung adenocarcinoma biology, drug metabolism, and respiratory viral infections. Its permissiveness to various pathogens makes it a relevant host for investigating host?Cvirus interactions, particularly those governed by innate immune factors like APOBEC3G.
APOBEC3G encodes a cytidine deaminase that restricts retroviruses and retrotransposons by inducing C-to-U hypermutations in single-stranded DNA, notably during HIV-1 reverse transcription. This enzyme acts downstream of interferon-alpha/beta and interferon-gamma signaling, with expression regulated by transcription factors such as STAT1, STAT2, IRF9, and NF-kappaB downstream of IFNAR1/2 and other cytokine receptors. APOBEC3G directly targets viral cDNA and host retroelements like LINE-1 and Alu sequences. It interacts with the HIV-1 Vif protein, which recruits a Cullin5?CElongin B/C?CCBF-beta E3 ubiquitin ligase complex to degrade APOBEC3G, thus counteracting its antiviral activity. Additionally, APOBEC3G cooperates with APOBEC3F, APOBEC3H, and interacts with cofactors such as RPA, DDX3, MOV10, and uracil DNA glycosylase (UNG), linking deamination to downstream DNA damage responses.
In the A-549 lung adenocarcinoma background, APOBEC3G knockout allows dissection of its dual roles in innate antiviral defense and potential cancer-associated mutagenesis. Lung epithelial cells are exposed to airborne pathogens and express interferon-responsive genes; thus, this model is valuable for studying how APOBEC3G limits viral replication in respiratory tissues. Moreover, since aberrant APOBEC activity can cause off-target genomic mutations, the knockout provides a clean system to evaluate its contribution to mutation accumulation in lung cancer cells, separate from its antiviral effects.
This polyclonal knockout product enables a variety of functional assays, including HIV-1 infectivity assays to assess restriction potency, immunoblotting and immunoprecipitation to examine Vif-mediated degradation, cytidine deamination activity measurements, and RT-qPCR or next-generation sequencing to quantify hypermutations in viral or retroelement targets. Researchers can also perform RNA-seq to profile interferon-stimulated genes or flow cytometric analyses using viral reporter systems. The cells are suitable for drug screens targeting the Vif?CAPOBEC3G axis or for investigating APOBEC3G-related mutation signatures in lung adenocarcinoma. For technical inquiries or custom services, please contact Ascent Research.
