claudin-3 CRISPR Activation Plasmid (h): sc-401756-ACT

CLDN3 encodes claudin-3, a tetra-span tight junction protein that contributes to epithelial barrier integrity and apical–basolateral polarity by regulating paracellular permeability and junctional strand architecture. Claudin-3 cooperates with other claudins and junctional scaffold proteins to coordinate cell–cell adhesion and signaling pathways linked to epithelial homeostasis, including crosstalk with EMT-associated remodeling programs. Altered CLDN3 expression and tight junction disorganization are frequently associated with epithelial tumor biology, where changes in barrier function and polarity can influence invasion, metastasis, and microenvironmental interactions. As a membrane-associated junctional component, claudin-3 is also relevant to studies of tissue compartmentalization, drug transport across epithelia, and lineage-specific differentiation states.

claudin-3 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous CLDN3 expression without altering the underlying DNA sequence.

claudin-3 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the CLDN3 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 CLDN3 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous claudin-3 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native CLDN3 locus and enabling the study of claudin-3-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of claudin-3 pathway restoration in tumor cells with silenced or reduced CLDN3 expression.

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