Rab 27b CRISPR Activation Plasmid (h): sc-403498-ACT

RAB27B encodes the small GTPase Rab 27b, a member of the Rab family that regulates membrane trafficking steps required for docking, priming, and fusion of secretory vesicles with the plasma membrane. Through interactions with effector proteins such as synaptotagmin-like proteins and Rab27-specific binding partners, Rab 27b coordinates regulated exocytosis, granule maturation, and cargo release in secretory and immune-related contexts. This pathway contributes to processes including platelet dense granule secretion, endocrine vesicle trafficking, and control of extracellular vesicle/exosome release, linking RAB27B to intercellular communication and microenvironmental signaling. Dysregulated Rab27b-dependent trafficking has been associated with altered secretion programs in inflammatory conditions and cancer biology, making it relevant for mechanistic studies of metastasis-related secretion, tumor–stroma interactions, and immune modulation.

Rab 27b CRISPR Activation Plasmid (h) provides a targeted, non-destructive approach to upregulating endogenous RAB27B expression without altering the underlying DNA sequence.

Rab 27b CRISPR Activation Plasmid (h) is a three-plasmid synergistic activation mediator (SAM) system engineered for highly efficient, site-specific transcriptional upregulation of the RAB27B 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 RAB27B transcriptional start site, where VP64, p65, and HSF1 act in concert to recruit transcriptional machinery and drive upregulation of endogenous Rab 27b expression. Unlike nuclease-active Cas9, dCas9 does not introduce double-strand breaks or modify the genomic sequence, preserving the native RAB27B locus and enabling the study of Rab 27b-dependent transcriptional responses at the endogenous locus, making it a valuable tool for functional studies, target gene identification, and the modeling of Rab 27b pathway restoration in tumor cells with silenced or reduced RAB27B expression.

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