MDR1/ABCB1 CRISPR Activation Plasmid (h): sc-400178-ACT

ABCB1 (MDR1/P-glycoprotein) is an ATP-binding cassette transporter that exports a broad range of xenobiotics and endogenous metabolites across the plasma membrane, shaping intracellular drug accumulation and barrier function. It is prominently expressed in epithelial and endothelial tissues, including intestine, liver, kidney, and the blood–brain barrier, where it contributes to detoxification and tissue protection. MDR1/ABCB1 activity intersects with pharmacokinetic and stress-response processes by limiting exposure to cytotoxic compounds and influencing cellular homeostasis. Dysregulated ABCB1 expression has been widely linked to multidrug resistance phenotypes in cancer models and to variability in drug response in neurological and inflammatory disease contexts.

MDR1/ABCB1 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous ABCB1 expression without altering the underlying DNA sequence.

MDR1/ABCB1 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the ABCB1 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 ABCB1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous MDR1/ABCB1 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native ABCB1 locus and enabling the study of MDR1/ABCB1-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of MDR1/ABCB1 pathway restoration in tumor cells with silenced or reduced ABCB1 expression.

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