HSF1 Lentiviral Activation Particles (h): sc-400432-LAC

Human HSF1 (heat shock factor 1) is a master transcriptional regulator of the proteostasis network that coordinates cellular adaptation to proteotoxic stress. Upon stress-induced trimerization and nuclear accumulation, HSF1 binds heat shock elements to induce chaperones and co-chaperones such as HSP70 and HSP90, linking protein folding capacity to ubiquitin–proteasome activity, autophagy, and restoration of protein homeostasis. Beyond acute stress responses, HSF1 integrates signals from mTOR and MAPK pathways to influence cell-cycle control, apoptosis resistance, and metabolic remodeling. Dysregulated HSF1 activity has been associated with neurodegeneration, inflammatory stress phenotypes, and oncogenic programs that support tumor cell survival under chronic proteotoxic stress, making it a key node for mechanistic studies of stress signaling.

HSF1 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 HSF1 upregulation across a broader range of human cell types.

HSF1 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 HSF1 transcriptional start site, where VP64, p65, and HSF1 act cooperatively to recruit endogenous transcriptional machinery and drive sustained upregulation of endogenous HSF1 expression. The use of nuclease-inactive dCas9 avoids the introduction of double-strand DNA breaks and preserves the native HSF1 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.