ERp72 CRISPR Activation Plasmid (h): sc-402689-ACT

Human PDIA4 encodes ERp72, an endoplasmic reticulum (ER) protein disulfide isomerase that catalyzes thiol–disulfide exchange to support oxidative folding and quality control of nascent secretory and membrane proteins. ERp72 functions within the ER proteostasis network alongside chaperones and other PDIs, contributing to ER-associated degradation (ERAD) and buffering perturbations that trigger the unfolded protein response (UPR). Through these activities, PDIA4 influences redox homeostasis, antigen presentation–related processing, and secretion capacity in highly secretory or stressed cells. Dysregulated ER proteostasis and PDI activity are frequently linked to inflammatory signaling, metabolic stress, and tumor cell adaptation, making PDIA4 a useful node for dissecting stress-response biology.

ERp72 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous PDIA4 expression without altering the underlying DNA sequence.

ERp72 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the PDIA4 locus in human cell lines. The system is built around a catalytically inactive Cas9 (dCas9) carrying two inactivating mutations (D10A and N863A) that eliminate nuclease activity while preserving DNA binding. This dCas9 is fused to VP64, a potent transcriptional activator, and is co-expressed with a blasticidin resistance gene for selection. The second plasmid encodes the MS2-p65-HSF1 fusion protein, a secondary activator complex that works in concert with dCas9-VP64, alongside a hygromycin resistance gene. The third plasmid encodes a target-specific 20 nt sgRNA fused to two MS2 RNA aptamers that recruit the MS2-p65-HSF1 complex to the activation site, accompanied by a puromycin resistance gene. The three plasmids are delivered at a 1:1:1 mass ratio for balanced expression of all system components.

Once assembled at the target locus, the SAM complex binds within approximately 200 bp upstream of the PDIA4 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous ERp72 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native PDIA4 locus and enabling the study of ERp72-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of ERp72 pathway restoration in tumor cells with silenced or reduced PDIA4 expression.

For Research Use Only. Not Intended for Diagnostic or Therapeutic Use.