Claspin CRISPR Activation Plasmid (h): sc-404153-ACT

Human CLSPN encodes Claspin, a replication checkpoint mediator that couples ATR signaling to CHK1 activation in response to replication stress and DNA damage. Claspin coordinates stabilization of stalled replication forks, S-phase checkpoint enforcement, and timing of origin firing to preserve genome integrity. Its activity intersects with DNA replication, DNA damage response, and cell-cycle control pathways, and altered checkpoint signaling has been associated with genomic instability observed across diverse cancer and hereditary genome maintenance disorders. CLSPN is therefore routinely studied in mechanisms of replication stress tolerance, chromosomal fragility, and sensitivity to genotoxic perturbations.

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

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

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