BLM CRISPR Activation Plasmid (h): sc-400896-ACT

BLM encodes a RecQ family DNA helicase that safeguards genome stability by resolving aberrant DNA structures during replication and recombination. BLM functions in homologous recombination repair, replication fork restart, and dissolution of double Holliday junctions with the TOP3A–RMI1/2 complex, thereby limiting sister chromatid exchanges and chromosomal rearrangements. It is integrated with DNA damage response networks involving ATR/ATM signaling and influences cell cycle checkpoint control under replication stress. Loss of BLM activity is associated with elevated mutational burden and chromosomal instability phenotypes characteristic of Bloom syndrome and is relevant to studies of cancer-associated genome maintenance defects.

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

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

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