musculin CRISPR Activation Plasmid (h): sc-403242-ACT

Human MSC encodes musculin, a basic helix–loop–helix (bHLH) transcription factor that regulates lineage-specific gene expression programs through sequence-specific DNA binding and cooperative interactions with other transcriptional regulators. Musculin influences cell fate decisions and differentiation-associated transcriptional networks, including myogenic and immune-related contexts where bHLH factors coordinate chromatin accessibility and transcriptional output. By modulating downstream target genes involved in proliferation, differentiation, and stress-responsive signaling, MSC contributes to cellular identity maintenance and remodeling of developmental gene programs. Dysregulated MSC expression has been reported across disease-relevant biological settings, supporting its use as a node for studying transcriptional rewiring and pathway perturbations in human cells.

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

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

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