The DNAJC1 knockout HT29 polyclonal cells represent a CRISPR/Cas9-edited human cell population designed for loss-of-function analysis of the ER cochaperone DNAJC1, also known as ERdj1. This product consists of a heterogeneous pool of cells carrying targeted disruptions of the DNAJC1 gene, providing a versatile polyclonal knockout model. The constitutive elimination of functional DNAJC1 protein enables researchers to investigate the consequences of impaired ER cochaperone activity in a colorectal adenocarcinoma background.
The parental HT29 cell line is derived from a human colorectal adenocarcinoma and is extensively used as an epithelial tumor model. HT29 cells display characteristic features of colorectal carcinoma, including mucin secretion and adenomatous polyposis coli (APC) mutations, making them suitable for exploring intestinal epithelial biology and oncogenic signaling. Their adherent growth and ability to establish tumors in xenograft models facilitate both in vitro and in vivo studies.
DNAJC1 (ERdj1) encodes an ER-resident member of the J-domain cochaperone family that partners with the Hsp70 chaperone BiP (HSPA5). DNAJC1 stimulates BiP’s ATPase activity, a function that couples BiP to cotranslational protein import through the Sec61 translocon and to polypeptide folding and ER-associated degradation (ERAD). Consequently, DNAJC1 knockout disrupts ER proteostasis, likely leading to accumulation of misfolded proteins and activation of chronic ER stress. DNAJC1 acts downstream of ER stress sensors and is transcriptionally regulated by ATF6, XBP1, and ATF4, while it promotes BiP activation, ER protein folding capacity, and clearance of ERAD substrates. Important components of the associated UPR pathways include IRE1, PERK, CHOP, HRD1, and SEL1L.
In colorectal carcinoma, UPR signaling is often dysregulated, contributing to tumor adaptation and chemoresistance. Loss of DNAJC1-mediated proteostasis control may sensitize HT29 cells to ER stress-inducing compounds or modulate their malignant properties. This knockout model thus offers a platform to examine how defects in ER protein quality control intersect with oncogenic pathways, potentially identifying vulnerabilities in cancer cells that depend on robust ER function for survival and microenvironmental interactions.
Researchers can employ these polyclonal DNAJC1 knockout HT29 cells to assess UPR activation by quantifying BiP, CHOP, and XBP1 via western blotting, or by detecting XBP1 splicing through RT-qPCR. The model is well-suited for testing ER-targeted chemotherapies and stress-inducing agents like tunicamycin, with cell viability and apoptosis measurable by flow cytometry. Additional applications include co-immunoprecipitation of residual BiP complexes, immunofluorescence-based monitoring of ER structure, and investigation of tumor?Cstroma communication under ER stress conditions. For more information, please contact Ascent Research.
