Mxi1 CRISPR Activation Plasmid (h): sc-403155-ACT

Human MXI1 encodes Mxi1, a basic helix–loop–helix leucine zipper transcriptional repressor that heterodimerizes with MAX and antagonizes MYC-driven gene expression programs. By recruiting corepressor complexes to E-box–containing regulatory regions, Mxi1 helps constrain proliferation, modulate cell-cycle progression, and support differentiation-associated transcriptional states. MXI1 activity intersects with MYC/MAX network signaling and broader chromatin-dependent transcriptional control mechanisms that shape cellular growth and stress responses. Dysregulation of MXI1 expression or function has been linked to altered MYC pathway output and is frequently examined in cancer biology and other contexts where transcriptional balance influences cell fate.

Mxi1 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous MXI1 expression without altering the underlying DNA sequence.

Mxi1 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the MXI1 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 MXI1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous Mxi1 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native MXI1 locus and enabling the study of Mxi1-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of Mxi1 pathway restoration in tumor cells with silenced or reduced MXI1 expression.

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