The KDELR1 Knockout HT29 Polyclonal Cells are a heterogeneous population of CRISPR/Cas9-edited HT29 colorectal adenocarcinoma cells with targeted disruption of the KDELR1 gene. This polyclonal knockout cell population provides a loss-of-function model for studying KDELR1 function in ER-Golgi retrograde transport and cellular homeostasis. The polyclonal format mitigates clonal biases and offers a genetically varied background, making it suitable for experiments requiring stable gene disruption to interrogate protein secretion and ER stress pathways.
The parental HT29 cell line is a human colorectal adenocarcinoma model derived from a female patient, exhibiting intestinal epithelial features. HT29 cells can form polarized monolayers and differentiate, enabling studies of cell polarity, trafficking, and secretion in a cancer context. Their tumorigenic background provides a relevant platform for investigating how oncogenic signaling intersects with fundamental processes like ER-Golgi transport and the unfolded protein response.
KDELR1 encodes the KDEL receptor 1, a Golgi transmembrane protein that retrieves escaped ER-resident proteins by binding C-terminal KDEL motifs on chaperones such as BiP (HSPA5) and calreticulin (CALR). This retrieval depends on interactions with the COPI complex, ARF1, and GBF1. KDELR1 transcription is upregulated by the unfolded protein response (UPR) via transcription factors XBP1s and ATF6, activated by ER stress sensors including IRE1. Downstream, proper ER homeostasis relies on KDEL-containing foldases like P4HB and ERp57 (PDIA3). Disruption of KDELR1 impairs this pathway, leading to secretion of ER-resident proteins and heightened ER stress.
In HT29 colorectal cancer cells, KDELR1 knockout provides a model to dissect ER-Golgi trafficking contributions to cancer cell biology. These cells often exhibit altered secretion and heightened ER stress due to rapid proliferation. Loss of KDELR1 can perturb ER proteostasis, affecting survival, proliferation, and drug responses. The intestinal epithelial nature of HT29 makes this model particularly relevant for studying secretory functions in epithelial barrier integrity, mucin secretion, and intercellular signaling, as well as UPR signaling and protein quality control under pathological conditions.
These KDELR1 knockout HT29 polyclonal cells enable studies of ER-Golgi retrograde transport, UPR activation using tunicamycin or thapsigargin, and protein secretion mechanisms. Assays including Western blotting for ER-resident protein secretion, immunofluorescence and confocal microscopy for trafficking, RT-qPCR for UPR target genes, and co-immunoprecipitation for protein interactions are applicable. Flow cytometry-based secretion assays can quantify cargo release. This model supports cancer cell biology, drug discovery targeting ER homeostasis, and functional genomics. For further technical inquiries, please contact Ascent Research.
