USF-1 CRISPR Activation Plasmid (h): sc-401345-ACT

USF1 encodes upstream stimulatory factor 1 (USF-1), a ubiquitously expressed bHLH-leucine zipper transcription factor that binds E-box motifs to coordinate gene programs controlling glucose and lipid metabolism, oxidative stress responses, and cell growth. USF-1 regulates transcriptional networks downstream of nutrient and hormonal signaling, integrating inputs from pathways such as insulin-responsive metabolism and stress-activated signaling to shape cellular homeostasis. Genetic and expression studies have associated altered USF1 activity with dyslipidemia, cardiometabolic traits, and broader regulatory variation affecting inflammatory and metabolic gene expression. Accordingly, USF1 is frequently studied as a transcriptional node linking metabolic regulation to gene–environment interactions in human cells.

USF-1 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous USF1 expression without altering the underlying DNA sequence.

USF-1 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the USF1 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 USF1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous USF-1 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native USF1 locus and enabling the study of USF-1-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of USF-1 pathway restoration in tumor cells with silenced or reduced USF1 expression.

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