The CALU Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population targeting the CALU gene. This mixed population of HAP1 cells harbors gene disruptions, offering a robust loss-of-function model for studying calumenin biology. The polyclonal format provides a heterogeneous pool that preserves biological variability, suitable for bulk assays without the biases of clonal selection.
HAP1 is a near-haploid human cell line derived from KBM-7 chronic myeloid leukemia cells in blast crisis. It is adherent and maintains a predominantly haploid karyotype, simplifying genetic manipulation and enabling direct observation of knockout phenotypes without wild-type allele compensation. This makes HAP1 an ideal host for functional genomics, cancer biology, and signaling research.
Calumenin, encoded by CALU, is a calcium-binding protein localized to the ER. It functions as an inhibitor of gamma-carboxylation of vitamin K-dependent clotting factors by interfering with GGCX activity and calcium availability. Upstream, ATF6 and XBP1 induce CALU expression during ER stress. Calumenin interacts with ryanodine receptors, SERCA2, and factor II, and modulates downstream targets including prothrombin, factor X, factor VII, and factor IX. This places CALU at the intersection of ER calcium homeostasis, the unfolded protein response, and the coagulation cascade.
In HAP1 cells, CALU knockout provides a powerful model to investigate its dual roles in coagulation and tumor biology. Loss of calumenin may enhance GGCX-mediated carboxylation, boosting clotting factor activity, while its overexpression has been linked to ER stress and progression in breast cancer and hepatocellular carcinoma. The haploid background ensures unambiguous genotype-phenotype relationships, facilitating dissection of these pathways in coagulation disorders, cancer, and beyond.
These polyclonal knockout cells are suitable for diverse assays including coagulation factor activity measurements, western blotting, RT-qPCR, and immunofluorescence to probe protein expression and localization. They enable functional studies on ER stress, calcium signaling, and protein secretion, as well as drug screening for coagulation disorders and cancer. Applications extend to apoptosis and migration/invasion assays to evaluate tumorigenic potential. For further details, please contact Ascent Research.
