cyt19 CRISPR Activation Plasmid (h): sc-404196-ACT

Human AS3MT encodes cyt19, an arsenite methyltransferase that catalyzes S-adenosylmethionine-dependent methylation of inorganic arsenic to mono- and dimethylated metabolites, shaping cellular arsenic biotransformation and redox homeostasis. This activity intersects with one-carbon metabolism and glutathione-linked detoxification pathways, influencing oxidative stress signaling and mitochondrial function under metalloid exposure. Genetic variation and altered expression of AS3MT are associated with inter-individual differences in arsenic metabolism and susceptibility to arsenic-related toxicities, making it relevant for mechanistic studies of environmental stress responses and metabolic regulation. AS3MT/cyt19 is therefore commonly investigated in models of hepatocyte, kidney, and vascular biology where xenobiotic processing and stress adaptation are central experimental variables.

cyt19 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous AS3MT expression without altering the underlying DNA sequence.

cyt19 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the AS3MT 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 AS3MT transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous cyt19 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native AS3MT locus and enabling the study of cyt19-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of cyt19 pathway restoration in tumor cells with silenced or reduced AS3MT expression.

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