DNAJC7 Knockout HCT 116 Polyclonal Cells constitute a CRISPR/Cas9-edited polyclonal knockout cell population disrupting the DNAJC7 gene in HCT 116 human colorectal carcinoma cells. This heterogeneous population retains diversity typical of polyclonal pools, avoiding clonal selection bias. Cells harbor targeted gene disruptions that ablate DNAJC7 protein expression, offering a robust loss-of-function model for studying co-chaperone biology. The polyclonal format ensures representation of multiple editing events, yielding an averaged phenotype suitable for bulk biochemical and genetic analyses.
HCT 116 is a colorectal carcinoma epithelial line featuring MSI-high status and MLH1 deficiency, widely used in cancer research for studying DNA repair, tumorigenesis, and drug responses. Its adherent growth and near-diploid genome make it a tractable model for investigating cellular pathways affected in colorectal cancer, including proteostasis networks. Owing to its mismatch repair defect, HCT 116 accumulates mutations and exhibits genetic instability, which provides a relevant background for exploring stress response mechanisms and chaperone dependency in cancer.
DNAJC7 (TPR2) is a tetratricopeptide repeat co-chaperone that directly binds HSPA8 (Hsc70) and HSPA1A (Hsp70), accelerating nucleotide exchange and facilitating substrate transfer into the Hsp70 folding cycle. Under conditions of heat shock or proteotoxic stress, HSF1 transcriptionally activates DNAJC7 expression. Beyond its intracellular chaperone role, DNAJC7 acts as a cell surface receptor for diphtheria toxin, mediating clathrin-dependent endocytosis. In the quality control network, DNAJC7 collaborates with DNAJB1 to deliver clients to Hsp70 and with the E3 ubiquitin ligase STUB1 and the co-chaperone BAG3 to target terminally misfolded proteins for degradation or aggresome sequestration. Consequently, disruption of DNAJC7 leads to impaired Hsp70 client processing, accumulation of aggregation-prone proteins, and altered stress-induced signaling cascades.
In the context of HCT 116 colorectal carcinoma, DNAJC7 ablation is particularly informative because the cell line’s inherent MSI-high and MLH1-null background creates a permissive environment for proteotoxic stress. The interaction between DNAJC7 and STUB1 suggests that the knockout may perturb ubiquitin-dependent proteasomal degradation, while the link to BAG3 indicates potential dysregulation of aggresome formation and autophagy. These disruptions could amplify the sensitivity of HCT 116 cells to heat shock, chemotherapeutic agents, and protein aggregation-inducing conditions, making this model valuable for probing the intersection of protein homeostasis and genomic instability. Furthermore, the polyclonal nature of the knockout allows the study of heterogenous stress adaptation phenotypes within a population, reflecting the cellular diversity found in tumors.
Key applications include confirming DNAJC7 loss by western blotting, monitoring Hsp70 client protein levels, assessing cell viability under heat shock, testing diphtheria toxin sensitivity, and visualizing protein aggregates with ProteoStat immunofluorescence. Co-immunoprecipitation can be used to evaluate interactions between Hsp70 isoforms and other chaperones. RT-qPCR enables quantification of heat shock gene expression changes. The polyclonal format supports pooled CRISPR screens, bulk RNA sequencing, and high-throughput proteostatic assays. For further details and technical support, contact Ascent Research.
