The HSPBP1 Knockout HT29 Polyclonal Cells comprise a CRISPR/Cas9-edited polyclonal population derived from the human HT29 colorectal adenocarcinoma cell line, with targeted disruption of the HSPBP1 gene encoding the Hsp70-binding protein 1 co-chaperone. This heterogeneous knockout pool eliminates clonal selection bias and is designed for pooled functional experiments exploring HSPBP1-dependent proteostasis, stress signaling, and cancer cell biology.
HT29 cells, originally isolated from a 44-year-old female colorectal adenocarcinoma, display epithelial morphology and carry inactivating APC and TP53 mutations as well as the oncogenic BRAF V600E mutation, resulting in constitutive MAPK signaling and dysregulated apoptosis. This widely used colorectal cancer model is well-suited for investigating chaperone-mediated protein quality control linked to mutant p53 and aberrant Wnt/??-catenin pathways.
HSPBP1 acts as a nucleotide exchange factor for HSP70 chaperones (HSPA1A/HSP70 and HSPA8/HSC70), accelerating ADP/ATP exchange to lower substrate-binding affinity, thus favoring client release for ubiquitin-proteasomal degradation. It directly interacts with HSP70, BAG2, and the E3 ligase STUB1/CHIP to coordinate client triage. Consequently, HSPBP1 knockouts are expected to prolong HSP70?Cclient interactions, stabilizing proteins such as mutant p53, Akt, and Raf-1, and affecting Bcl-2 family-mediated apoptosis. Expression is induced by HSF1 under heat shock, oxidative stress, and unfolded protein response, integrating stress signals with proteostasis.
In the HT29 context, HSPBP1 disruption likely enhances HSP70-dependent stabilization of oncogenic drivers, including mutant p53, BRAF V600E downstream effectors, and Akt, potentially altering cell survival, proliferation, and apoptotic thresholds. Such changes may modulate sensitivity to HSP70 inhibitors or proteasome inhibitors, making this model valuable for pharmacological studies. The polyclonal format captures heterogeneous responses, reflecting tumor diversity and enhancing statistical robustness in pooled functional assays.
Applications include stress response profiling, chaperone-targeted drug testing, apoptosis signaling, and protein homeostasis analyses. Users can perform co-immunoprecipitation and Western blotting for HSP70?Cclient complexes, Annexin V/PI apoptosis assays, cell viability under proteotoxic stress, proteasome activity measurements, RT-qPCR of stress genes, and flow cytometry for cell cycle. This tool facilitates dissection of chaperone?Cproteasome networks in colorectal cancer. For technical inquiries, please contact Ascent Research.
