The MAPKAPK3 Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population from the Raji B-cell line, featuring targeted disruption of the MAPKAPK3 gene to create a loss-of-function model. This heterogeneous pool avoids monoclonal artifacts and enables study of stress and inflammatory signaling. CRISPR/Cas9-mediated gene disruption ablates MAPKAPK3 expression, facilitating dissection of its roles in B-cell contexts.
The host cell line, Raji, is a human Burkitt lymphoma B-cell line that is Epstein-Barr virus (EBV)-positive and exhibits surface expression of CD19, CD20, and IgM. Raji cells are widely used as a model for B-cell biology, lymphomagenesis, and immune response studies, including antibody production and antigen presentation. Their transformed phenotype and EBV status make them particularly relevant for investigating oncogenic signaling, tumor microenvironment interactions, and drug resistance mechanisms. The knockout of MAPKAPK3 in this background allows for the examination of kinase-dependent pathways in a well-characterized lymphoma model.
MAPKAPK3 encodes a serine/threonine kinase downstream of the p38 MAPK pathway, activated by MAPK14 (p38??) in response to cytokines like TNF-?? and IL-1??, osmotic stress, and UV radiation. Once activated, it phosphorylates HSPB1 (Hsp27) at Ser78 to promote actin remodeling and cell migration, and targets transcription factors ATF1 and CREB1 to modulate gene expression. Additionally, MAPKAPK3 phosphorylates mRNA-binding proteins such as ZFP36 to regulate mRNA stability, influencing inflammatory responses. It interacts with 14-3-3 proteins and forms complexes with MAPK14 and HSPB1, thereby integrating stress signals to control cell survival, motility, and post-transcriptional regulation.
In the Raji B-lymphoma context, MAPKAPK3 knockout provides a powerful tool to dissect p38??-MAPKAPK3 signaling in B-cell malignancies. Given Raji’s use as a model for Burkitt lymphoma, the polyclonal knockout cells enable studies on how MAPKAPK3 influences lymphoma cell migration, invasion, and drug resistance. The EBV-positive background also allows exploration of viral-host interactions and stress responses relevant to lymphomagenesis. By disrupting a key node in the stress-activated protein kinase pathway, this model helps elucidate mechanisms of cytokine post-transcriptional regulation and stress granule dynamics that may contribute to tumor cell survival and immune evasion.
Researchers can employ these cells in a variety of assays, including Western blotting for phospho-HSPB1 (Ser78) to assess kinase activity, RT-qPCR for cytokine mRNA stability, immunofluorescence for stress granule formation, and flow cytometry for apoptosis (Annexin V). Transwell migration/invasion assays can delineate the role of MAPKAPK3 in cell motility, while co-immunoprecipitation with p38?? can verify protein interactions. Drug sensitivity tests (MTT/ATP viability) and phospho-signaling analysis further enable investigation of resistance mechanisms. For further inquiries, contact Ascent Research.
