MDR1/ABCB1 CRISPR Activation Plasmid (m): sc-422215-ACT

Mouse Abcb1b encodes the multidrug resistance transporter MDR1/ABCB1, an ATP-binding cassette efflux pump that limits intracellular accumulation of structurally diverse xenobiotics and metabolites. By coupling ATP hydrolysis to substrate export, MDR1 influences pharmacokinetic barriers and cellular detoxification programs, shaping processes such as epithelial transport, blood–tissue barrier function, and stress responses to toxic insults. Its activity intersects with inflammatory and metabolic signaling through regulation of intracellular exposure to signaling lipids and environmental chemicals, and it is frequently studied in the context of drug disposition and multidrug resistance phenotypes. Dysregulated MDR1/ABCB1 expression is relevant to models of treatment-refractory disease and to mechanistic studies of transporter-mediated bioavailability in vivo.

MDR1/ABCB1 CRISPR Activation Plasmid (m) provides a targeted, non-destructive approach to upregulating endogenous Abcb1b expression without altering the underlying DNA sequence.

MDR1/ABCB1 CRISPR Activation Plasmid (m) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the Abcb1b 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 Abcb1b 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 Abcb1b 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 Abcb1b expression.

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