HEL308 CRISPR Activation Plasmid (h): sc-404447-ACT

HELQ encodes the human DNA helicase HEL308, an ATP-dependent SF2 helicase that helps resolve stalled DNA replication intermediates and promotes genome stability during replication stress. HEL308 participates in pathways linked to DNA repair and replication fork processing, including mechanisms that interface with homologous recombination and the Fanconi anemia network for interstrand crosslink tolerance. By supporting accurate DNA replication and damage response signaling, HELQ influences cellular outcomes such as checkpoint engagement, chromosomal integrity, and survival under genotoxic stress. Altered HELQ function or expression has been associated in the literature with genomic instability phenotypes and susceptibility contexts relevant to cancer biology and DNA repair–associated disorders.

HEL308 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous HELQ expression without altering the underlying DNA sequence.

HEL308 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the HELQ 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 HELQ transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous HEL308 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native HELQ locus and enabling the study of HEL308-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of HEL308 pathway restoration in tumor cells with silenced or reduced HELQ expression.

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