MDR3/ABCB4 Lentiviral Activation Particles (h): sc-404167-LAC

ABCB4 (MDR3) encodes a hepatocyte canalicular ATP-binding cassette transporter that translocates phosphatidylcholine from the inner to the outer leaflet of the canalicular membrane for secretion into bile. By supplying phospholipids that form mixed micelles with bile acids, MDR3 supports bile formation, membrane protection, and hepatobiliary lipid homeostasis within bile acid transport and lipid trafficking pathways. Loss or reduction of ABCB4 activity is linked to cholestatic liver phenotypes and altered biliary composition, making it relevant to studies of bile acid–induced injury, inflammatory signaling, and transporter network regulation. ABCB4 is therefore widely used as a model for investigating canalicular membrane dynamics and cross-talk with other hepatic transporters.

MDR3/ABCB4 Lentiviral Activation Particles (h) address this need by packaging the complete synergistic activation mediator (SAM) transcriptional activation system into transduction-ready, high-titer lentiviral particles, enabling efficient ABCB4 upregulation across a broader range of human cell types.

MDR3/ABCB4 Lentiviral Activation Particles (h) deliver all functional components of the synergistic activation mediator (SAM) system via lentiviral transduction. The system comprises three particle preparations co-transduced into target cells: one encoding catalytically inactive dCas9 (D10A and N863A mutations) fused to the VP64 transactivation domain with a blasticidin resistance gene; one encoding the MS2-p65-HSF1 fusion protein with a hygromycin resistance gene; and one encoding a target-specific 20 nt sgRNA fused to two MS2 RNA aptamers with a puromycin resistance gene. Following lentiviral transduction and genomic integration of the expression cassettes, the SAM components are stably expressed and assemble at the target locus within the proximal promoter region upstream of the ABCB4 transcriptional start site, where VP64, p65, and HSF1 act cooperatively to recruit endogenous transcriptional machinery and drive sustained upregulation of endogenous MDR3/ABCB4 expression. The use of nuclease-inactive dCas9 avoids the introduction of double-strand DNA breaks and preserves the native ABCB4 genomic locus and regulatory architecture.

The lentiviral format offers several practical advantages: stable genomic integration supports heritable activation across cell divisions; high-titer particle preparations eliminate the need for in-house viral production; and compatibility with primary, non-dividing, and transfection-resistant cell types expands experimental accessibility. Successful transduction can be confirmed and enriched through triple antibiotic selection using puromycin, hygromycin, and blasticidin.

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