20S Proteasome α3 CRISPR Activation Plasmid (h): sc-401857-ACT

PSMA3 encodes the 20S proteasome α3 subunit, a core component of the 20S catalytic barrel that forms the proteolytic hub of the ubiquitin–proteasome system. By supporting 26S proteasome assembly and regulated degradation of short-lived and misfolded proteins, α3 helps maintain proteostasis and shapes signaling networks controlling cell cycle progression, DNA damage responses, and stress-adaptive transcription. Proteasome activity also influences antigen processing for MHC class I presentation and the turnover of pathway effectors such as NF-κB regulators, thereby linking PSMA3 function to inflammation and immune surveillance. Dysregulated proteasome capacity and subunit composition are associated with cancer cell fitness, neurodegenerative proteinopathies, and altered responses to oxidative or ER stress, making PSMA3 a relevant target for mechanistic studies of proteostasis-driven disease biology.

20S Proteasome α3 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous PSMA3 expression without altering the underlying DNA sequence.

20S Proteasome α3 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the PSMA3 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 PSMA3 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous 20S Proteasome α3 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native PSMA3 locus and enabling the study of 20S Proteasome α3-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of 20S Proteasome α3 pathway restoration in tumor cells with silenced or reduced PSMA3 expression.

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