TIF1β CRISPR Activation Plasmid (h): sc-401999-ACT

TRIM28, also known as TIF1β (KAP1), is a KRAB-associated transcriptional corepressor that coordinates epigenetic gene silencing by recruiting chromatin modifiers such as SETDB1 and the NuRD/HDAC complex to establish H3K9me3-marked heterochromatin. It plays central roles in regulation of transposable elements, genomic stability, DNA damage responses, and maintenance of cell identity through broad control of transcriptional programs. TRIM28-dependent repression interfaces with pathways controlling chromatin organization, ubiquitin-mediated signaling, and developmental transcriptional networks. Dysregulation of TRIM28/TIF1β activity has been linked to altered differentiation states and aberrant transcriptional repression observed across multiple disease-relevant contexts, including oncogenic epigenetic remodeling and neurodevelopmental phenotypes.

TIF1β CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous TRIM28 expression without altering the underlying DNA sequence.

TIF1β CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the TRIM28 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 TRIM28 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous TIF1β expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native TRIM28 locus and enabling the study of TIF1β-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of TIF1β pathway restoration in tumor cells with silenced or reduced TRIM28 expression.

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