PA200 CRISPR Activation Plasmid (h): sc-404513-ACT

PSME4 encodes PA200, a proteasome activator that associates with the 20S core particle to modulate proteasome gate opening and peptide processing. PA200 is implicated in ubiquitin-independent proteasomal degradation and is frequently linked to nuclear proteostasis, including regulation of chromatin-associated protein turnover during DNA damage responses and spermatogenesis-associated processes. By shaping proteasome activity, PA200 can influence pathways controlling cell-cycle progression, genome stability, and stress-adaptive remodeling of the proteome. Altered PSME4 expression has been reported across multiple disease contexts where proteostasis and DNA repair are perturbed, supporting its study as a mechanistic node in protein quality control and nuclear stress signaling.

PA200 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous PSME4 expression without altering the underlying DNA sequence.

PA200 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the PSME4 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 PSME4 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous PA200 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native PSME4 locus and enabling the study of PA200-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of PA200 pathway restoration in tumor cells with silenced or reduced PSME4 expression.

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