FKBP14 Knockout Raji Polyclonal Cells are a heterogeneous population of Raji B lymphocytes engineered via CRISPR/Cas9-mediated disruption of the FKBP14 gene. This polyclonal knockout model introduces targeted gene inactivation across the cell pool, enabling studies of FKBP14 loss-of-function without clonal selection biases. The cells serve as a versatile tool for investigating ER proteostasis and collagen biogenesis in a lymphoblastoid background.
The Raji cell line, established from a Burkitt’s lymphoma patient, is an Epstein-Barr virus (EBV)-positive B lymphoblastoid model widely used in immunology and cancer research. Raji cells exhibit robust secretory pathway activity and express components of the unfolded protein response (UPR), making them suitable for probing ER stress dynamics. Their lymphoblastoid origin provides a relevant context for examining B cell-specific ER functions and stress adaptation mechanisms.
FKBP14 encodes an ER-resident peptidyl-prolyl cis-trans isomerase that interacts with procollagens, including COL1A1 and COL3A1, and collaborates with chaperones such as HSPA5 (BiP) and PDIA3 to ensure proper collagen folding and cross-linking. Disruption of FKBP14 triggers the accumulation of misfolded procollagens, activating the canonical UPR branches mediated by ATF6, IRE1, and PERK. This leads to downstream induction of CHOP and other ER stress-responsive genes. FKBP14 loss also affects extracellular matrix organization by impairing collagen secretion. The protein is transcriptionally regulated by ATF6 and responds to ER stress stimuli like tunicamycin, placing it centrally in the ER quality control machinery.
In Raji B lymphocytes, FKBP14 knockout provides a unique opportunity to dissect how professional secretory cells manage collagen-specific ER stress. Since Raji cells do not naturally produce large amounts of collagen, the model allows study of ectopic or induced collagen synthesis and its impact on B cell physiology. Activation of the UPR in these cells upon FKBP14 loss highlights the sensitivity of lymphoblastoid ER to perturbations in protein folding. This system is particularly valuable for modeling connective tissue disorder-associated ER stress in a hematopoietic background, complementing studies in fibroblast or osteoblast models.
Researchers can employ these polyclonal knockout cells in Western blotting and RT-qPCR analyses to monitor expression of FKBP14, UPR markers (e.g., ATF6, CHOP, HSPA5), and collagen transcripts. Immunofluorescence and collagen secretion assays enable visualization of ER morphology alterations and extracellular matrix defects. Flow cytometry-based apoptosis detection facilitates assessment of cell viability under ER stress conditions, including tunicamycin treatment. These applications support investigations into Ehlers-Danlos syndrome (kyphoscoliotic type) pathology, secretory pathway dynamics, and B cell ER proteostasis. For further technical details or bulk ordering, please contact Ascent Research.
