TTF/Transcription Termination Factor/TTF1 CRISPR Activation Plasmid (h): sc-407927-ACT

TTF1 (transcription termination factor 1) is a nucleolar DNA-binding protein that regulates RNA polymerase I transcription by promoting rRNA gene transcription termination and organizing rDNA chromatin structure. By controlling termination, replication fork barriers, and nucleolar architecture, TTF1 contributes to ribosome biogenesis, genome stability, and cell-cycle-associated growth programs. Perturbation of rDNA transcription and nucleolar stress responses linked to TTF1-dependent processes are frequently associated with dysregulated proliferation and altered proteostasis in cancer-related biology. TTF1 therefore serves as a useful node for studying nucleolar function, rDNA repeat regulation, and transcription–replication coordination in human cells.

TTF/Transcription Termination Factor/TTF1 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous TTF1 expression without altering the underlying DNA sequence.

TTF/Transcription Termination Factor/TTF1 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the TTF1 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 TTF1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous TTF/Transcription Termination Factor/TTF1 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native TTF1 locus and enabling the study of TTF/Transcription Termination Factor/TTF1-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of TTF/Transcription Termination Factor/TTF1 pathway restoration in tumor cells with silenced or reduced TTF1 expression.

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