USF-1 CRISPR Activation Plasmid (m): sc-423628-ACT

Upstream stimulatory factor 1 (Usf1) encodes the USF-1 transcription factor, a basic helix–loop–helix leucine zipper protein that binds E-box motifs to coordinate gene expression programs controlling cellular metabolism, differentiation, and stress responses. In mouse cells, USF-1 integrates nutrient and hormonal signaling to regulate lipid and glucose homeostasis, mitochondrial and oxidative pathways, and circadian-associated transcriptional networks. Through its promoter- and enhancer-level activity, USF-1 influences chromatin accessibility and transcriptional output across metabolic tissues and immune-relevant contexts. Dysregulated USF1/USF-1 activity has been linked to cardiometabolic phenotypes, including altered lipoprotein handling and insulin sensitivity, supporting its use in mechanistic studies of metabolic disease biology.

USF-1 CRISPR Activation Plasmid (m) provides a targeted, non-destructive approach to upregulating endogenous Usf1 expression without altering the underlying DNA sequence.

USF-1 CRISPR Activation Plasmid (m) 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.