FIG4 CRISPR Activation Plasmid (h): sc-404404-ACT

FIG4 encodes a SAC phosphoinositide 5-phosphatase that regulates turnover of phosphatidylinositol 3,5-bisphosphate (PI(3,5)P2), a lipid signal critical for endolysosomal membrane dynamics. Through functional coupling with the PIKfyve complex, FIG4 helps control vesicle trafficking, vacuole/lysosome homeostasis, autophagic flux, and membrane fission–fusion events that shape endosome maturation. Perturbation of FIG4 activity disrupts phosphoinositide balance and is linked to defects in neuronal maintenance and myelin biology, reflecting high sensitivity of the nervous system to endolysosomal stress. As a result, FIG4 is frequently studied in models of neurodegeneration and peripheral neuropathy where lysosomal dysfunction and impaired trafficking are central mechanisms.

FIG4 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous FIG4 expression without altering the underlying DNA sequence.

FIG4 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the FIG4 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 FIG4 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous FIG4 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native FIG4 locus and enabling the study of FIG4-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of FIG4 pathway restoration in tumor cells with silenced or reduced FIG4 expression.

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