ABCA4 CRISPR Activation Plasmid (h): sc-401830-ACT

ABCA4 encodes an ATP-binding cassette (ABC) transporter predominantly expressed in retinal photoreceptors, where it localizes to outer segment disc membranes and functions in the visual cycle. ABCA4 mediates ATP-dependent transport of retinoid conjugates, helping clear N-retinylidene-phosphatidylethanolamine and related intermediates to limit accumulation of cytotoxic bisretinoids such as A2E. Through its role in retinoid handling, ABCA4 supports photoreceptor homeostasis and intersects with pathways governing lipid transport, oxidative stress, and retinal pigment epithelium–photoreceptor interactions. Dysregulation or reduced activity of ABCA4 is strongly associated with inherited retinal degenerations, including Stargardt disease and ABCA4-related cone-rod dystrophy, making it a key target for mechanistic studies of retinal pathobiology.

ABCA4 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous ABCA4 expression without altering the underlying DNA sequence.

ABCA4 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the ABCA4 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 ABCA4 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous ABCA4 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native ABCA4 locus and enabling the study of ABCA4-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of ABCA4 pathway restoration in tumor cells with silenced or reduced ABCA4 expression.

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