The GMDS Knockout Raji Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the Raji B lymphocyte line, targeting the human GMDS gene. This product provides a loss-of-function model for GDP-mannose 4,6-dehydratase, which catalyzes the conversion of GDP-mannose to GDP-4-keto-6-deoxymannose in de novo fucose biosynthesis. The polyclonal population contains multiple independent gene-disrupted alleles, offering a heterogeneous knockout system suitable for studying fucose-dependent processes without clonal bias.
The host cell line, Raji, is an EBV-positive Burkitt lymphoma-derived B lymphocyte line widely used as an immortalized model of mature B cells. These cells retain key B cell signaling pathways, including B cell receptor activation and NF-??B signaling, making them particularly relevant for investigating B cell biology, lymphomagenesis, and immune cell functions. The Raji background enables studies of fucosylation in the context of B cell activation, antibody production, and lymphoma progression, where glycosylation alterations are known to influence disease.
GMDS is a key enzyme in the fucosylation pathway, operating immediately downstream of GDP-mannose and upstream of GDP-fucose synthesis. The enzyme??s product, GDP-4-keto-6-deoxymannose, is further converted by FX/TSTA3 to GDP-fucose, which is transported into the Golgi by SLC35C1 and utilized by fucosyltransferases (FUT family) to modify glycoproteins and glycolipids. Knockout of GMDS abolishes cellular GDP-fucose production, impairing fucosylation of Notch receptors and selectin ligands such as sialyl Lewis X. Consequently, downstream signaling through Notch-mediated transcription and selectin-mediated cell adhesion is disrupted. In B cells, GMDS function is regulated upstream by B cell receptor activation, NF-??B pathway, and cytokines like IL-4 and CD40L, while its activity directly influences fucosyltransferases and glycans critical for immune cell interactions.
In the Raji lymphoma model, loss of GMDS provides a powerful tool to dissect fucosylation-dependent processes that govern B cell behavior. Since Raji cells express selectin ligands like PSGL-1 and Notch receptors, GMDS knockout is expected to reduce sialyl Lewis X presentation and Notch fucosylation, altering cell adhesion, migration, and signal transduction. This model can reveal how fucosylation modulates B cell activation downstream of the BCR and NF-??B, and how it contributes to lymphoma cell homing and metastasis. Moreover, GMDS deficiency may mimic congenital disorders of glycosylation linked to immune dysregulation, offering insights into Notch-related developmental defects and cancer biology.
Researchers can employ this knockout model in a variety of assays to explore glycan biology and B cell pathology. Representative applications include Western blot and lectin blot analysis of fucosylated proteins, flow cytometry for sialyl Lewis X expression, Notch reporter assays to assess signaling activity, and adhesion/migration assays to E-selectin to evaluate selectin-dependent interactions. RNA-seq can further characterize transcriptional changes resulting from impaired fucosylation. These experiments support investigations into cancer metastasis, immune cell trafficking, and Notch-dependent processes. For additional details and ordering information, please contact Ascent Research.
