Stim1 CRISPR Activation Plasmid (h): sc-401311-ACT

STIM1 encodes stromal interaction molecule 1 (Stim1), an endoplasmic reticulum Ca2+ sensor that initiates store-operated calcium entry (SOCE) by coupling ER calcium depletion to activation of ORAI channels at ER–plasma membrane contact sites. This calcium signaling axis coordinates cytosolic Ca2+ oscillations that regulate transcriptional programs, cytoskeletal remodeling, secretion, and cell-cycle progression through pathways including calcineurin–NFAT and MAPK signaling. STIM1-dependent SOCE is a central determinant of immune cell activation and broader calcium homeostasis across many tissues. Dysregulated STIM1 activity and Ca2+ influx dynamics have been associated with altered inflammatory signaling, neuromuscular function, and cancer-relevant phenotypes such as migration and metabolic adaptation, supporting its use as a mechanistic node in disease modeling.

Stim1 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous STIM1 expression without altering the underlying DNA sequence.

Stim1 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the STIM1 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 STIM1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous Stim1 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native STIM1 locus and enabling the study of Stim1-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of Stim1 pathway restoration in tumor cells with silenced or reduced STIM1 expression.

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