The HSPBP1 Knockout HEK293T Polyclonal Cells represent a CRISPR/Cas9-mediated gene-disrupted cell population designed to ablate HSPBP1 function in a human embryonic kidney background. This polyclonal product comprises a heterogeneous pool of HEK293T cells with targeted disruption of the HSPBP1 gene, which encodes a co-chaperone that negatively regulates HSP70 ATPase activity. By avoiding the bottleneck of clonal selection, this model retains genetic diversity suitable for robust functional studies of stress responses and protein quality control.
HEK293T cells are derived from human embryonic kidney epithelium and have been transformed with sheared adenovirus type 5 DNA, resulting in constitutive expression of the SV40 large T-antigen. This background is widely recognized for its exceptionally high transfection efficiency and capacity for recombinant protein expression, attributes that persist in the knockout population. The epithelial origin and well-characterized chaperone network make HEK293T cells an ideal host for investigating the interplay between protein folding, ubiquitin-proteasome degradation, and apoptosis.
HSPBP1 functions as a nucleotide exchange factor antagonist by binding directly to the ATPase domain of stress-inducible HSP70 (HSPA1A) and constitutively expressed HSC70 (HSPA8), thereby inhibiting chaperone cycling and client refolding. Through its interaction with the co-chaperone BAG3, HSPBP1 channels misfolded substrates, including the tumor suppressor p53, the microtubule-associated protein tau, and CFTR, toward ubiquitin-proteasome degradation mediated by the E3 ligase CHIP (STUB1). The HSPBP1 gene is transcriptionally activated by HSF1 in response to oxidative and endoplasmic reticulum stress, linking its expression to cellular stress sensors. Consequently, loss of HSPBP1 disrupts proteostasis and sensitizes cells to stress-induced apoptosis via BAX and caspase pathways.
Disruption of HSPBP1 in HEK293T cells creates a versatile platform for dissecting the molecular mechanisms by which co-chaperone regulation influences cellular stress sensitivity and protein aggregation. The high transfection efficiency of the parental line permits facile reconstitution with wild-type or mutant HSPBP1, enabling structure-function analyses of its interactions. This model is particularly relevant to cancer biology, where proteotoxic stress resistance is pivotal, and to neurodegenerative diseases and ischemic injury, where protein misfolding and apoptosis are central pathological features.
Investigators can employ this knockout population in a range of experimental workflows, including western blotting for HSPBP1 and HSP70, RT-qPCR, and co-immunoprecipitation of HSP70 complexes. Functional assays such as cell viability under heat shock or proteasome inhibition with bortezomib, Annexin V/PI apoptosis staining, and proteasome activity measurements further elucidate the downstream consequences of HSPBP1 loss. For additional technical information, please contact Ascent Research.
