Lubricin CRISPR Activation Plasmid (h): sc-402340-ACT

PRG4 encodes lubricin, a secreted mucin-like glycoprotein enriched in synovial fluid and at cartilage surfaces where it supports boundary lubrication and protects tissues from shear-driven damage. Lubricin contributes to extracellular matrix homeostasis by limiting protein adsorption and cellular adhesion, modulating chondrocyte and synoviocyte interactions with the joint microenvironment. Altered PRG4 expression or lubricin composition has been associated with joint degeneration and synovial inflammation phenotypes, and is frequently studied in the context of osteoarthritis and cartilage injury models. In addition to musculoskeletal biology, PRG4 is used as a marker for specialized lubricating cell populations and for investigating how mechanical stress reshapes secretory and matrix-associated programs.

Lubricin CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous PRG4 expression without altering the underlying DNA sequence.

Lubricin CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the PRG4 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 PRG4 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous Lubricin expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native PRG4 locus and enabling the study of Lubricin-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of Lubricin pathway restoration in tumor cells with silenced or reduced PRG4 expression.

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