MaxiKα CRISPR Activation Plasmid (h): sc-402208-ACT

KCNMA1 encodes MaxiKα (BK) channel α-subunit, a large-conductance Ca2+- and voltage-activated K+ channel that integrates intracellular Ca2+ signals with membrane depolarization to regulate cellular excitability. By shaping action potential repolarization and controlling afterhyperpolarization, MaxiKα influences neurotransmitter release, smooth muscle tone, endocrine secretion, and vascular reactivity. The channel is functionally coupled to Ca2+ microdomains and signaling pathways that tune ion flux, membrane potential, and Ca2+ homeostasis, including interactions with auxiliary β/γ subunits that modulate gating kinetics. Dysregulated KCNMA1 activity has been associated with neurological excitability phenotypes, vascular and airway smooth muscle dysfunction, and altered cellular proliferation programs relevant to electrophysiology and ion channelopathies research.

MaxiKα CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous KCNMA1 expression without altering the underlying DNA sequence.

MaxiKα CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the KCNMA1 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 KCNMA1 transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous MaxiKα expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native KCNMA1 locus and enabling the study of MaxiKα-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of MaxiKα pathway restoration in tumor cells with silenced or reduced KCNMA1 expression.

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