p55 CRISPR Activation Plasmid (h): sc-409649-ACT

Human MPP1 encodes the membrane palmitoylated protein p55, a MAGUK family scaffolding factor that helps organize membrane-associated protein complexes and couple them to the cortical actin–spectrin cytoskeleton. p55 participates in junctional stability and membrane domain architecture through interactions with FERM-domain proteins and other cytoskeletal adaptors, influencing cell shape, polarity, and trafficking. In erythrocytes, MPP1 contributes to membrane mechanical integrity and organization of specialized microdomains, processes relevant to red blood cell deformability and membrane stability phenotypes. Altered p55-dependent scaffolding has been investigated in contexts where cytoskeletal anchoring and cell–cell contact regulation are perturbed, providing a framework for studying membrane organization in normal and disease-associated states.

p55 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous MPP1 expression without altering the underlying DNA sequence.

p55 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the MPP1 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 MPP1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous p55 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native MPP1 locus and enabling the study of p55-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of p55 pathway restoration in tumor cells with silenced or reduced MPP1 expression.

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