Gastrin CRISPR Activation Plasmid (h): sc-403220-ACT

Human GAST encodes gastrin, a peptide hormone primarily produced by gastric G cells that regulates gastric acid secretion, mucosal growth, and gastrointestinal motility. Gastrin signals mainly through the cholecystokinin B receptor (CCKBR), activating intracellular pathways such as PLC/PKC, MAPK/ERK, and calcium-dependent signaling to modulate epithelial proliferation and secretory programs. Dysregulated gastrin expression and altered gastrin–CCKBR signaling have been linked to hypergastrinemia-associated remodeling of the gastric mucosa and broader perturbations of digestive endocrine homeostasis. As a marker and regulator of gastric endocrine function, GAST is frequently studied in models of gastric physiology, inflammation-associated signaling, and epithelial differentiation.

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

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

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