The CIT Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the human Raji B lymphoblast line, featuring targeted disruption of the CIT gene encoding citron kinase. This polyclonal pool provides a robust loss-of-function model for dissecting the roles of citron kinase in B-cell contexts, without isolation of single-cell clones, and maintains a mixed genetic background that reflects population-level effects. As a gene-edited product, the cells are designed to enable reproducible studies of CIT-dependent pathways through standard culture and assay workflows, offering a versatile tool for investigating cytokinesis, Rho GTPase signaling, and cell division regulation.
The parental Raji cell line is an Epstein-Barr virus (EBV)-positive B lymphoblast model originally established from a Burkitt lymphoma patient. Raji cells grow in suspension, exhibit high transfection efficiency, and are widely utilized in immunology and oncology research to study B-cell receptor signaling, lymphomagenesis, and antiviral responses. Their EBV-transformed status confers continuous proliferation and allows interrogation of viral?Chost interactions that may intersect with cell cycle regulation. This well-characterized background makes Raji cells particularly suitable for examining the molecular machinery governing lymphocyte division and genomic stability.
CIT encodes a serine/threonine kinase that acts downstream of activated RhoA, a small GTPase that orchestrates actin cytoskeleton dynamics. Upon RhoA binding, citron kinase phosphorylates myosin light chain (MLC), promoting actomyosin ring contraction essential for cleavage furrow ingression and midbody maturation during cytokinesis. The kinase also interacts with a network of mitotic regulators: the CDK1/CCNB1 complex acts as an upstream activator, while ECT2 and PRC1 facilitate RhoA activation at the equatorial cortex. Additionally, citron kinase associates with the kinesin KIF20A, actin, and myosin II to coordinate spindle orientation and abscission. Disruption of CIT thus uncouples RhoA-mediated signals from the contractile machinery, offering a defined entry point for mechanistic studies.
In the Raji B-cell context, loss of citron kinase function is predicted to impair cytokinesis, leading to binucleated or polyploid cells that arise from failed abscission. Such ploidy alterations can be readily monitored by flow cytometry and are relevant to understanding chromosomal instability in lymphoma. Moreover, Raji cells expressing EBV latent proteins may engage Rho GTPase pathways differently than non-transformed B cells, making this knockout model valuable for exploring how oncogenic viruses intersect with cell division checkpoints. The polyclonal nature of the product mimics the heterogeneity observed in tumor populations, enhancing its utility for drug sensitivity profiling and functional genomics screens.
Researchers can employ this polyclonal knockout population in diverse assays to dissect CIT biology. Western blotting confirms loss of citron kinase and reduced MLC phosphorylation, while immunofluorescence detection of midbody markers such as KIF20A, PRC1, and acetylated tubulin visualizes cytokinesis failure. Flow cytometry-based DNA content analysis quantifies polyploidy, and time-lapse imaging captures dynamic cleavage furrow regression. Furthermore, RhoA pulldown assays can assess whether upstream signaling remains intact in the absence of CIT. These applications support investigations ranging from basic cell division mechanisms to B-cell lymphoma pathobiology and neurodevelopmental disorder modeling. For additional product details, please contact Ascent Research.
