The DNAJC5 Knockout NCI-H1975 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population derived from the NCI-H1975 human lung adenocarcinoma cell line, harboring a targeted disruption of the DNAJC5 gene. This loss-of-function model abolishes expression of cysteine string protein alpha (CSP??), a synaptic vesicle co-chaperone, enabling in-depth investigation of CSP??-mediated protein homeostasis and trafficking processes in a cancer-relevant epithelial background.
NCI-H1975 is a widely employed non-small cell lung cancer (NSCLC) cell line established from a female patient and characterized by the presence of EGFR L858R and T790M activating and resistance mutations. It serves as a key model for studying EGFR tyrosine kinase inhibitor (TKI) resistance and epithelial signaling biology, endowing the DNAJC5 knockout variant with a clinically relevant mutation context for dissecting chaperone?Concogene interplay.
CSP??, encoded by DNAJC5, functions as a J-domain co-chaperone that recruits Hsp70/HSPA8 chaperones to client proteins, particularly the SNARE complex components SNAP25 and syntaxin-1, to facilitate proper protein folding and prevent aggregation. CSP?? also interacts with synaptotagmin, 14-3-3 proteins, and Hsc70, and is regulated by HSF1 under heat shock and ER stress conditions, as well as by palmitoylation-dependent membrane anchoring. Downstream, CSP?? supports SNARE complex stability and neurotransmitter release; ablation of DNAJC5 disrupts Hsp70-dependent chaperone activity, leading to impaired SNARE-mediated membrane fusion, accumulation of misfolded proteins, and aberrant activation of the JNK stress kinase pathway.
In the NCI-H1975 background, loss of CSP?? introduces chronic proteotoxic stress and altered vesicle trafficking, which may intersect with EGFR-driven survival signaling and TKI resistance mechanisms. The JNK pathway, which is influenced by CSP??, is known to modulate apoptosis and cell migration downstream of EGFR, positioning this knockout model as a unique tool to dissect how co-chaperone dysfunction impacts lung adenocarcinoma cell fitness, stress adaptation, and drug sensitivity.
Researchers can employ this polyclonal knockout population to study the role of CSP?? in non-neuronal contexts, investigate chaperone-mediated regulation of SNARE proteins in cancer, and explore how proteostasis perturbation influences EGFR TKI response. Representative assays include western blotting for CSP?? and SNAP25, RT-qPCR for DNAJC5, co-immunoprecipitation with Hsp70, apoptosis and migration/invasion analyses, phospho-JNK profiling, and EGFR inhibitor sensitivity testing. For additional details or technical support, please contact Ascent Research.
