Stim1 Lentiviral Activation Particles (h): sc-401311-LAC

Human STIM1 encodes stromal interaction molecule 1 (Stim1), an endoplasmic reticulum Ca²⁺ sensor that detects luminal Ca²⁺ depletion and couples to ORAI channels to trigger store-operated calcium entry (SOCE). This signaling axis shapes cytosolic Ca²⁺ dynamics that control NFAT-dependent transcription, cell-cycle progression, metabolic adaptation, and cytoskeletal remodeling. Stim1-dependent SOCE is central to immune cell activation and broader calcium-regulated processes, and altered STIM1 activity has been linked to immune dysfunction and other pathologies involving aberrant calcium signaling. As a proximal regulator of Ca²⁺ influx, STIM1 provides a mechanistic entry point for dissecting calcium-dependent pathways and stress responses in human cells.

Stim1 Lentiviral Activation Particles (h) address this need by packaging the complete synergistic activation mediator (SAM) transcriptional activation system into transduction-ready, high-titer lentiviral particles, enabling efficient STIM1 upregulation across a broader range of human cell types.

Stim1 Lentiviral Activation Particles (h) deliver all functional components of the synergistic activation mediator (SAM) system via lentiviral transduction. The system comprises three particle preparations co-transduced into target cells: one encoding catalytically inactive dCas9 (D10A and N863A mutations) fused to the VP64 transactivation domain with a blasticidin resistance gene; one encoding the MS2-p65-HSF1 fusion protein with a hygromycin resistance gene; and one encoding a target-specific 20 nt sgRNA fused to two MS2 RNA aptamers with a puromycin resistance gene. Following lentiviral transduction and genomic integration of the expression cassettes, the SAM components are stably expressed and assemble at the target locus within the proximal promoter region upstream of the STIM1 transcriptional start site, where VP64, p65, and HSF1 act cooperatively to recruit endogenous transcriptional machinery and drive sustained upregulation of endogenous Stim1 expression. The use of nuclease-inactive dCas9 avoids the introduction of double-strand DNA breaks and preserves the native STIM1 genomic locus and regulatory architecture.

The lentiviral format offers several practical advantages: stable genomic integration supports heritable activation across cell divisions; high-titer particle preparations eliminate the need for in-house viral production; and compatibility with primary, non-dividing, and transfection-resistant cell types expands experimental accessibility. Successful transduction can be confirmed and enriched through triple antibiotic selection using puromycin, hygromycin, and blasticidin.

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