cathepsin L CRISPR Activation Plasmid (h): sc-400804-ACT

Human CTSL encodes cathepsin L, a lysosomal cysteine protease that mediates intracellular protein turnover and peptide processing within the endolysosomal system. Cathepsin L contributes to autophagy-lysosome flux, extracellular matrix remodeling following secretion, and proteolytic activation events that intersect with antigen processing and inflammatory signaling. Dysregulated CTSL activity has been associated with altered tumor cell invasion and metastasis, fibrosis-related remodeling, and pathogen entry processes that depend on endosomal protease activity. As a nodal component of proteostasis and lysosome-dependent pathways, CTSL is frequently studied in contexts linking cellular stress responses to immune regulation and tissue remodeling.

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

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

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