GRK 4 CRISPR Activation Plasmid (h): sc-402816-ACT

Human GRK4 (G protein-coupled receptor kinase 4) is a serine/threonine kinase that phosphorylates activated GPCRs, promoting receptor desensitization and internalization through β-arrestin–dependent mechanisms. It is prominently studied in dopaminergic and renal signaling contexts, where it can modulate receptor responsiveness and downstream second messenger pathways such as cAMP/PKA. GRK4 activity influences cellular signal termination, receptor trafficking, and adaptive signaling rewiring that shapes membrane receptor homeostasis. Genetic variation and altered expression of GRK4 have been investigated in relation to cardiometabolic and renal phenotypes, supporting its relevance for mechanistic studies of GPCR-driven disease biology.

GRK 4 CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous GRK4 expression without altering the underlying DNA sequence.

GRK 4 CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the GRK4 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 GRK4 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous GRK 4 expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native GRK4 locus and enabling the study of GRK 4-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of GRK 4 pathway restoration in tumor cells with silenced or reduced GRK4 expression.

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