HEXIM1 CRISPR Activation Plasmid (h): sc-402333-ACT

Human HEXIM1 (hexamethylene bis-acetamide inducible 1) encodes a nuclear regulatory protein that restrains transcriptional elongation by sequestering P-TEFb (CDK9–Cyclin T) within the 7SK snRNP complex, thereby limiting RNA polymerase II CTD phosphorylation and pause release. Through this control of CDK9-dependent elongation, HEXIM1 influences stimulus-responsive gene expression programs, cell-cycle progression, and differentiation-associated transcriptional networks. Altered HEXIM1 expression or disruption of 7SK/P-TEFb homeostasis has been linked to transcriptional dysregulation observed in proliferative and stress-adaptation contexts, making HEXIM1 a useful node for studying mechanisms that couple signaling inputs to genome-wide transcription output. Investigating HEXIM1 function supports research into transcriptional control, chromatin-associated regulation, and disease-relevant pathways driven by aberrant elongation dynamics.

HEXIM1 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous HEXIM1 expression without altering the underlying DNA sequence.

HEXIM1 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the HEXIM1 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 HEXIM1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous HEXIM1 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native HEXIM1 locus and enabling the study of HEXIM1-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of HEXIM1 pathway restoration in tumor cells with silenced or reduced HEXIM1 expression.

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