cathepsin S CRISPR Activation Plasmid (m): sc-419881-ACT

Mouse Ctss encodes cathepsin S, a lysosomal cysteine protease that remains active at near-neutral pH and supports antigen processing through degradation of the invariant chain to facilitate MHC class II peptide loading. It contributes to endolysosomal protein turnover, extracellular matrix remodeling, and regulation of inflammatory signaling in antigen-presenting cells, including macrophages and dendritic cells. Ctss activity intersects with immune pathways that shape adaptive immune activation and can influence tissue remodeling within inflammatory microenvironments. Dysregulated cathepsin S expression or activity has been linked to autoimmune and inflammatory phenotypes and is frequently examined in models of neuroinflammation, atherosclerosis, and tumor-associated immunity.

cathepsin S CRISPR Activation Plasmid (m) provides a targeted, non-destructive approach to upregulating endogenous Ctss expression without altering the underlying DNA sequence.

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

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