MaxiKβ CRISPR Activation Plasmid (h): sc-403096-ACT

KCNMB1 encodes the β1 auxiliary subunit of large-conductance, calcium- and voltage-activated potassium (BK/MaxiK) channels, commonly referred to as MaxiKβ. By increasing channel calcium sensitivity and modifying gating kinetics, MaxiKβ tunes membrane excitability and potassium efflux in smooth muscle and other excitable tissues, thereby influencing vascular tone, airway reactivity, and cellular calcium handling. This modulatory activity links KCNMB1 to signaling processes that integrate intracellular Ca2+ dynamics with membrane potential, including pathways controlling contraction–relaxation coupling and stimulus-dependent hyperpolarization. Altered BK channel regulation and KCNMB1 variation have been studied in the context of cardiovascular and smooth muscle–related phenotypes, supporting its relevance for mechanistic work on ion channel regulation and excitability-associated disease biology.

MaxiKβ CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous KCNMB1 expression without altering the underlying DNA sequence.

MaxiKβ CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the KCNMB1 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 KCNMB1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous MaxiKβ expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native KCNMB1 locus and enabling the study of MaxiKβ-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of MaxiKβ pathway restoration in tumor cells with silenced or reduced KCNMB1 expression.

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