DNAJC3 Knockout Raji Polyclonal Cells provide a CRISPR/Cas9-mediated loss-of-function model in a human B lymphocyte background. This product consists of a polyclonal knockout cell population derived from Raji cells, with targeted disruption of the DNAJC3 gene. The resulting polyclonal pool abolishes functional expression of the encoded ER co-chaperone p58IPK, enabling investigation of its regulatory roles in the unfolded protein response (UPR). These cells are supplied as a ready-to-use, heterogeneous knockout population suitable for functional genomics, drug screening, and mechanistic studies in B cell biology and ER stress signaling.
Raji is an Epstein-Barr virus (EBV)-positive human Burkitt lymphoma B-cell line widely employed in immunological and cancer research. Originating from a B lymphocyte, this cell line maintains key features of antigen-presenting cells and is extensively used to model B cell malignancies. Raji cells express surface markers such as CD19 and CD20, and their EBV-driven transformation provides a relevant context for studying oncogenic signaling and immune interactions. The robust growth characteristics and well-characterized signaling networks make Raji an ideal host for examining UPR dynamics in B cell lymphomas.
DNAJC3 encodes p58IPK, an ER-resident co-chaperone that functions as a critical negative regulator of the PERK branch of the UPR. Under ER stress, p58IPK interacts with PERK (EIF2AK3) and inhibits its kinase activity, thereby reducing phosphorylation of eukaryotic initiation factor 2?? (eIF2??). This attenuates global translational repression and limits the expression of the downstream transcription factor ATF4, which in turn controls CHOP (DDIT3)-mediated apoptosis. p58IPK also interacts with BiP/GRP78 (HSPA5) and associates with the IRE1??-XBP1 pathway, highlighting its broader role in coordinating ER proteostasis. Through these interactions, DNAJC3 serves to fine-tune the UPR, balancing survival and apoptotic outcomes during prolonged ER stress.
In Raji B cells, disruption of DNAJC3 is predicted to derepress PERK activity, leading to sustained eIF2?? phosphorylation and enhanced ATF4-CHOP signaling upon ER stress. This amplifies the pro-apoptotic arm of the UPR, potentially increasing susceptibility to ER stress-induced cell death. Given the intrinsic activation of UPR pathways in B cell malignancies due to high secretory loads, the DNAJC3 knockout model in Raji cells provides a powerful system to dissect the contribution of co-chaperone regulation to lymphoma cell survival. It also enables exploration of therapeutic vulnerabilities, as many cancer cells rely on UPR adaptation for growth.
This knockout cell pool is well-suited for a variety of research applications, including investigation of ER stress signaling, B cell lymphoma biology, and apoptosis mechanisms. Researchers can employ Western blotting to monitor changes in phospho-eIF2??, ATF4, CHOP, and BiP levels, or use RT-qPCR to quantify XBP1 splicing and UPR target gene induction. Functional assays such as Annexin V/PI apoptosis analysis and MTT viability tests allow assessment of ER stress sensitivity. Additionally, co-immunoprecipitation can probe altered interactions among UPR sensors and chaperones. For further details, please contact Ascent Research to learn how this innovative knockout model can accelerate your discovery pipelines.
