MIST1 CRISPR Activation Plasmid (h): sc-402094-ACT

BHLHA15 encodes MIST1, a basic helix–loop–helix transcription factor that drives maturation and secretory architecture in professional exocrine cells, including pancreatic acinar, gastric chief, and salivary gland lineages. MIST1 coordinates transcriptional programs that support regulated exocytosis, apical–basal polarity, and expansion of the endoplasmic reticulum and secretory granule network, intersecting with pathways governing ER homeostasis and differentiation. Altered MIST1 activity has been linked to exocrine cell dedifferentiation, acinar stress responses, and lineage plasticity during inflammatory remodeling. These features make BHLHA15 a useful node for studying epithelial differentiation states and secretory tissue dysfunction relevant to pancreatitis-associated changes and pancreatic tumorigenesis models.

MIST1 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous BHLHA15 expression without altering the underlying DNA sequence.

MIST1 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the BHLHA15 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 BHLHA15 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous MIST1 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native BHLHA15 locus and enabling the study of MIST1-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of MIST1 pathway restoration in tumor cells with silenced or reduced BHLHA15 expression.

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