SAP 155 CRISPR Activation Plasmid (h): sc-402925-ACT

SF3B1 encodes SAP 155, a core component of the SF3b subcomplex within the U2 snRNP that is required for branch point recognition and accurate intron removal during pre-mRNA splicing. By helping assemble and stabilize the spliceosome at the 3′ splice site, SAP 155 influences alternative splicing programs that shape proteome diversity and coordinate RNA processing with transcriptional regulation. Disruption of SF3B1-dependent splice site selection perturbs RNA maturation and can alter expression of pathways controlling cell-cycle progression, DNA damage responses, and differentiation. SF3B1 is frequently studied in the context of spliceosome biology and disease-associated mis-splicing, where recurrent coding variants are linked to widespread aberrant splicing and transcriptome rewiring.

SAP 155 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous SF3B1 expression without altering the underlying DNA sequence.

SAP 155 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the SF3B1 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 SF3B1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous SAP 155 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native SF3B1 locus and enabling the study of SAP 155-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of SAP 155 pathway restoration in tumor cells with silenced or reduced SF3B1 expression.

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