hnRNP I CRISPR Activation Plasmid (m): sc-422470-ACT

Mouse Ptbp1 encodes heterogeneous nuclear ribonucleoprotein I (hnRNP I/PTBP1), an RNA-binding protein that regulates pre-mRNA alternative splicing, 3′ end processing, mRNA stability, and internal ribosome entry site–dependent translation. hnRNP I shapes tissue-specific transcript programs and influences cell-state transitions by controlling exon selection in networks linked to neuronal differentiation, proliferation, and metabolic adaptation. Through coordinated control of RNA maturation and translation, PTBP1 interfaces with pathways governing cytoskeletal remodeling and stress-responsive gene expression. Dysregulated PTBP1 activity has been associated with altered RNA splicing landscapes relevant to neurodevelopmental phenotypes and oncogenic remodeling of gene expression programs, making it a useful target for mechanistic studies of RNA processing.

hnRNP I CRISPR Activation Plasmid (m) provides a targeted, non-destructive approach to upregulating endogenous Ptbp1 expression without altering the underlying DNA sequence.

hnRNP I CRISPR Activation Plasmid (m) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the Ptbp1 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 Ptbp1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous hnRNP I expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native Ptbp1 locus and enabling the study of hnRNP I-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of hnRNP I pathway restoration in tumor cells with silenced or reduced Ptbp1 expression.

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