Hemoglobin δ CRISPR Activation Plasmid (h): sc-401567-ACT

HBD encodes the delta globin chain of human hemoglobin, a core component of adult hemoglobin A2 that contributes to erythrocyte oxygen transport and redox homeostasis. Delta globin expression is tightly coupled to erythroid differentiation programs and globin locus control region–mediated transcription, integrating with heme biosynthesis, iron handling, and hemoglobin assembly pathways. Variation in HBD expression or sequence can influence hemoglobin composition and serves as a molecular readout in studies of globin switching and erythropoiesis. Altered globin-chain balance is relevant to inherited hemoglobin disorders, where compensatory changes in minor hemoglobin fractions are frequently investigated as modifiers of disease biology.

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

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

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