Sigma Receptor CRISPR Activation Plasmid (h): sc-400615-ACT

Human SIGMAR1 encodes the sigma receptor 1 (Sigma Receptor), an ER-resident and mitochondria-associated membrane (MAM) chaperone that modulates inter-organelle Ca²⁺ exchange, lipid homeostasis, and proteostasis during cellular stress. SIGMAR1 influences signaling outputs from IP3R-dependent Ca²⁺ flux, ER stress/UPR pathways, and mitochondrial bioenergetics, thereby shaping synaptic function, neurite maintenance, and cell survival programs. Through interactions with ion channels, GPCR signaling components, and redox regulators, Sigma Receptor integrates stress adaptation with neurotransmission and metabolic regulation. Dysregulation of SIGMAR1-associated processes has been linked to neurodegeneration and neuropathic phenotypes, supporting its utility in mechanistic studies of proteostasis failure and mitochondrial dysfunction.

Sigma Receptor CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous SIGMAR1 expression without altering the underlying DNA sequence.

Sigma Receptor CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the SIGMAR1 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 SIGMAR1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous Sigma Receptor expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native SIGMAR1 locus and enabling the study of Sigma Receptor-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of Sigma Receptor pathway restoration in tumor cells with silenced or reduced SIGMAR1 expression.

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