CD81 CRISPR Activation Plasmid (h2): sc-400185-ACT-2

Human CD81 encodes a tetraspanin cell-surface protein that organizes membrane microdomains and regulates receptor clustering, adhesion, and signal transduction in immune and non-immune cells. CD81 participates in B cell co-receptor function with CD19/CD21, modulates integrin-dependent trafficking, and influences pathways controlling antigen presentation, cell activation, and vesicle/exosome biogenesis. Dysregulated CD81 expression or compartmentalization has been linked to altered immune signaling and tumor cell behavior, supporting its use as a marker and mechanistic node in immunology and oncology research. CD81 is widely applied in studies of membrane protein complexes, extracellular vesicle characterization, and pathogen–host interactions where tetraspanin networks govern entry and cell-to-cell spread.

CD81 CRISPR Activation Plasmid (h2) provides a targeted, non-destructive approach to upregulating endogenous CD81 expression without altering the underlying DNA sequence.

CD81 CRISPR Activation Plasmid (h2) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the CD81 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 CD81 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous CD81 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native CD81 locus and enabling the study of CD81-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of CD81 pathway restoration in tumor cells with silenced or reduced CD81 expression.

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