Calretinin CRISPR Activation Plasmid (h): sc-401389-ACT

Human CALB2 encodes calretinin, a cytosolic EF-hand calcium-binding protein that shapes intracellular Ca2+ buffering and signal transduction in excitable and neuroendocrine-like cells. Calretinin influences activity-dependent calcium dynamics, synaptic excitability, and downstream transcriptional programs that couple calcium flux to neuronal differentiation and survival pathways. In research settings, CALB2 expression is widely used to define distinct neuronal subtypes and interneuron lineages, and it also supports functional studies of calcium-dependent network behavior. Dysregulated CALB2 has been reported across multiple disease-relevant contexts, including altered neurodevelopmental signaling and tumor-associated lineage states, motivating mechanistic studies of CALB2-driven calcium signaling phenotypes.

Calretinin CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous CALB2 expression without altering the underlying DNA sequence.

Calretinin CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the CALB2 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 CALB2 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous Calretinin expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native CALB2 locus and enabling the study of Calretinin-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of Calretinin pathway restoration in tumor cells with silenced or reduced CALB2 expression.

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