Lsh CRISPR Activation Plasmid (h): sc-402466-ACT

Human HELLS encodes lymphoid-specific helicase (Lsh), a SNF2-family ATP-dependent chromatin remodeler that cooperates with DNA methyltransferases to establish and maintain DNA methylation and heterochromatin organization. Lsh supports replication-coupled chromatin assembly, pericentromeric repeat silencing, and genome stability by regulating nucleosome positioning and higher-order chromatin structure. Through these epigenetic functions, HELLS influences transcriptional programs controlling cell cycle progression and differentiation, and its dysregulation is associated with altered methylation landscapes and genomic instability phenotypes observed across multiple disease contexts. HELLS is therefore widely studied in pathways governing epigenetic inheritance, transposon repression, and DNA repair–linked chromatin remodeling.

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

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

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