Histone H1 CRISPR Activation Plasmid (h): sc-404845-ACT

HIST1H1B encodes histone H1.5, a linker histone H1 family member that binds nucleosomal DNA at the entry/exit sites to promote higher-order chromatin compaction and regulate genome accessibility. By modulating chromatin structure, Histone H1 influences transcriptional control, DNA replication timing, and the coordination of DNA damage responses and repair. Altered expression or post-translational regulation of H1 variants is associated with epigenetic dysregulation, aberrant differentiation programs, and proliferative phenotypes observed across multiple disease contexts, supporting its utility as a mechanistic node in chromatin and transcription research.

Histone H1 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous HIST1H1B expression without altering the underlying DNA sequence.

Histone H1 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the HIST1H1B 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 HIST1H1B transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous Histone H1 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native HIST1H1B locus and enabling the study of Histone H1-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of Histone H1 pathway restoration in tumor cells with silenced or reduced HIST1H1B expression.

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