SAMHD1 CRISPR Activation Plasmid (h): sc-406002-ACT

Human SAMHD1 (SAM and HD domain-containing protein 1) is a dNTP triphosphohydrolase that regulates intracellular deoxynucleotide pools, thereby influencing DNA replication fidelity, repair capacity, and genome stability. By controlling dNTP availability, SAMHD1 interfaces with replication stress responses and DNA damage signaling pathways, including processes that shape cell-cycle progression and maintenance of nucleotide homeostasis. SAMHD1 also restricts retroviral replication in myeloid and resting T cells by limiting dNTP substrates required for reverse transcription, linking it to innate immune regulation. Dysregulation or mutation of SAMHD1 has been associated with inflammatory and autoimmune phenotypes and has been studied in the context of virus–host interactions and cancer-associated replication stress.

SAMHD1 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous SAMHD1 expression without altering the underlying DNA sequence.

SAMHD1 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the SAMHD1 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 SAMHD1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous SAMHD1 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native SAMHD1 locus and enabling the study of SAMHD1-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of SAMHD1 pathway restoration in tumor cells with silenced or reduced SAMHD1 expression.

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