FBL19 CRISPR Activation Plasmid (h): sc-407318-ACT

FBXL19 (FBL19) encodes an F-box protein that functions as a substrate recognition component of SCF (SKP1–CUL1–F-box) E3 ubiquitin ligase complexes, linking specific proteins to ubiquitin-dependent turnover. Through regulated proteostasis, FBXL19 contributes to control of cell-state transitions and transcriptional programs, with reported roles in chromatin-associated processes and signaling-dependent gene regulation. As part of ubiquitin–proteasome system pathways, altered FBXL19 activity can perturb protein homeostasis and downstream networks governing proliferation, differentiation, and stress responses. Dysregulation of ubiquitin ligases, including F-box proteins, is frequently associated with cancer biology and developmental phenotypes, making FBXL19 a relevant node for mechanistic studies.

FBL19 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous FBXL19 expression without altering the underlying DNA sequence.

FBL19 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the FBXL19 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 FBXL19 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous FBL19 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native FBXL19 locus and enabling the study of FBL19-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of FBL19 pathway restoration in tumor cells with silenced or reduced FBXL19 expression.

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