PA28γ CRISPR Activation Plasmid (h): sc-403397-ACT

PSME3 encodes the human proteasome activator subunit PA28γ, a nuclear regulator of 20S proteasome function that modulates ATP- and ubiquitin-independent protein turnover. PA28γ contributes to proteostasis control, impacts cell cycle progression and stress responses, and influences degradation of select regulatory proteins that shape transcriptional programs. Through its role in proteasome-mediated processing, PA28γ intersects with pathways governing DNA damage responses, chromatin-associated regulation, and inflammatory signaling. Altered PSME3 expression or activity has been linked in the literature to dysregulated proliferation and oncogenic phenotypes, supporting its use as a mechanistic node in cancer biology and proteasome pathway studies.

PA28γ CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous PSME3 expression without altering the underlying DNA sequence.

PA28γ CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the PSME3 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 PSME3 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous PA28γ expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native PSME3 locus and enabling the study of PA28γ-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of PA28γ pathway restoration in tumor cells with silenced or reduced PSME3 expression.

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