The DPY19L3 Knockout HAP1 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal population of HAP1 cells harboring disruption of the DPY19L3 gene. This loss-of-function model enables the study of C-mannosyltransferase activity and its role in protein glycosylation and cellular signaling without the confounding effects of DPY19L3 expression. The polyclonal format provides a heterogeneous knockout pool, suitable for robust functional genomics experiments where clonal variation is minimized.
The HAP1 cell line is a near-haploid human cell line originally derived from the chronic myeloid leukemia (CML) cell line KBM-7. Its haploid genome (except for a disomic fragment of chromosome 15) simplifies genetic analysis and facilitates the generation of knockout models, making it a widely used platform for functional genomics, drug target identification, and phenotypic screening. HAP1 cells retain many signaling pathways characteristic of their myeloid origin, providing a relevant context for studying oncogenic processes and protein processing pathways.
DPY19L3 encodes an endoplasmic reticulum (ER)-resident C-mannosyltransferase that catalyzes the transfer of ??-mannose from dolichol-phosphate-mannose to the C2 atom of tryptophan within the WXXW motif of thrombospondin type 1 repeats (TSRs). This modification is essential for the proper folding, secretion, and function of TSR-containing proteins such as thrombospondin-1 (THBS1), thrombospondin-2 (THBS2), ADAMTS proteases, and properdin. The expression and activity of DPY19L3 are regulated by the unfolded protein response (UPR) transcription factors ATF6 and XBP1s, linking C-mannosylation to ER stress pathways. DPY19L3 functions within a network that includes interacting partners calnexin, calreticulin, and DPM synthase, which collectively govern glycoprotein quality control in the ER.
Disruption of DPY19L3 in the HAP1 background ablates C-mannosylation activity, offering a clean system to dissect the contribution of this rare post-translational modification to TSR-protein biology. The near-haploid nature of HAP1 cells ensures that the knockout is effectively hemizygous, eliminating confounding wild-type alleles and enabling unambiguous genotype-phenotype correlations. This model is particularly valuable for investigating how loss of C-mannosylation affects ER homeostasis, protein secretion, and downstream signaling events mediated by thrombospondins and ADAMTS proteases in a leukemic cell context.
This knockout product is well-suited for a broad range of experimental approaches. Western blotting with antibodies against TSR-containing proteins can assess the maturation and secretion of client proteins. Immunofluorescence microscopy allows visualization of ER localization and potential protein retention. Functional assays such as cell migration and invasion assays can probe the role of C-mannosylation in cell motility, while co-immunoprecipitation experiments enable analysis of substrate interactions with calnexin or calreticulin. Lectin blotting and mass spectrometry-based glycosylation profiling provide detailed readouts of mannose modification on target proteins, and qPCR for UPR target genes can measure ER stress responses. Together, these applications support functional genomics studies of C-mannosylation, thrombospondin signaling, cancer cell biology, and drug target validation. For further inquiries, please contact Ascent Research.
