Promoters
Promoters are DNA regulatory sequences that recruit transcription machinery to initiate gene expression. They vary in transcriptional strength, temporal activity patterns, tissue selectivity, and susceptibility to silencing in different cellular environments.
| Name | Full Name | Strength | Tissue |
|---|---|---|---|
| 5×UAS | Five tandem GAL4 upstream activation sequences with the adenovirus E1B minimal promoter (5×UAS-E1B) | inducible | None intrinsic to this element — the activity pattern is set entirely by the co-expressed GAL4 driver line, not by the UAS-E1B sequence itself |
| 503unc | Zebrafish 503-bp unc-45b (503unc) promoter | strong | Skeletal and cardiac muscle in Danio rerio, including adaxial cells, slow and fast muscle fibers, and cranial, fin, and trunk muscle (Berger and Currie 2013) |
| α1-Tubulin | Drosophila melanogaster alpha-1-tubulin (αTub84B) promoter | moderate | Constitutive. The alpha1 gene is one of two constitutively expressed alpha-tubulin genes, unlike the male-specific alpha2 and maternal alpha4 genes (Theurkauf et al. 1986). |
| ACTA1 | Human skeletal muscle alpha-actin 1 (ACTA1) promoter | strong | Differentiated skeletal myofibers (myotubes); inactive in nonmuscle cell lines and confirmed non-recombining in cardiac muscle in vivo |
| Actin5C | Drosophila melanogaster cytoskeletal actin 5C (Act5C) distal promoter | strong | Not tissue-restricted in culture. Active without induction in Drosophila S2 cells (Angelichio et al. 1991) and in the C2 (larval CNS-derived) and S2R+ (late embryo-derived) cell lines (Qin et al. 2010). |
| ADH1 (long) | Saccharomyces cerevisiae alcohol dehydrogenase 1 (ADH1) promoter, long form | moderate | Not applicable; unicellular S. cerevisiae, constitutively active in all cells |
| ADH1 (medium) | Saccharomyces cerevisiae alcohol dehydrogenase 1 (ADH1) promoter, medium truncation | moderate | Not applicable; unicellular S. cerevisiae, constitutively active in all cells |
| ADH1 (short) | Saccharomyces cerevisiae alcohol dehydrogenase 1 (ADH1) promoter, short truncation | weak | Not applicable; unicellular S. cerevisiae, constitutively active in all cells |
| Adipoq | Mouse adiponectin (Adipoq) promoter | strong | Mature white and brown adipocytes; unlike the aP2/FABP4 promoter, not active in adipose-tissue macrophages (Wang et al. 2010) |
| AFP/βglobin | Mouse alpha-fetoprotein enhancer II fused to a human beta-globin minimal promoter (AFP/β-globin) | moderate | Fetal liver, yolk sac, and fetal gut; silenced in normal adult liver and reactivated during liver regeneration (Vacher and Tilghman, 1990; Jin et al. 2009) |
| Alb | Mouse albumin (Alb) promoter | strong | Differentiated hepatocytes; requires the far-upstream enhancer for efficient liver-specific expression |
| AOX1 | Komagataella phaffii (Pichia pastoris) alcohol oxidase 1 (AOX1) promoter | inducible | Not applicable; unicellular K. phaffii (P. pastoris) |
| aP2 | Rat adipocyte fatty acid binding protein 4 (aP2/FABP4) promoter | strong | Mature white and brown adipocytes; also natively active in adipose-tissue macrophages, unlike the more restricted Adipoq promoter (Makowski et al. 2001) |
| ApoE/hAAT | Apolipoprotein E hepatic control region/human alpha-1-antitrypsin composite promoter (LP1) | strong | Differentiated hepatocytes; liver-restricted ApoE-HCR/hAAT composite promoter |
| β-actin2 | Zebrafish cytoskeletal beta-actin 2 (bactin2/actb2) promoter | strong | Broad/ubiquitous across most tissues and developmental stages, though less consistent than the ubi promoter in blood cells and fin (Higashijima et al. 1997; Mosimann et al. 2011). |
| BK5 | Bovine keratin 5 (BK5) promoter | moderate | Basal epithelial cells of stratified squamous epithelia — epidermis, esophageal and foregastric mucosa, cervicovaginal epithelium, and thymic medullary epithelium — recapitulating endogenous keratin 5 expression (Ramirez et al. 1994; Liang et al. 2009) |
| CAG | CMV early enhancer/chicken β-actin/rabbit β-globin hybrid promoter (CAG) | strong | Ubiquitous — active across mammalian cell types, consistently among the strongest constitutive promoters tested though absolute output varies by cell type (Qin et al. 2010). |
| CaMKIIα (long) | Mouse alpha-calcium/calmodulin-dependent protein kinase II (CaMKIIα) promoter (8.5 kb) | strong | Excitatory neurons of adult forebrain — cortex, hippocampus, and striatum; minimal expression in cerebellum or non-neuronal tissue |
| CaMKIIα (short) | Mouse alpha-calcium/calmodulin-dependent protein kinase II (CaMKIIα) promoter (1.3 kb) | strong | Excitatory pyramidal neurons in cortex and hippocampus; also expressed in a subset of cortical GABAergic interneurons (parvalbumin, somatostatin, nNOS, NPY subtypes) |
| 2×CaMV35S | Enhanced cauliflower mosaic virus 35S (2×CaMV35S) promoter | strong | Broad across dicot tissues, most pronounced in leaves, stems, and cotyledons; weaker in monocots and inactive in pollen |
| CaMV35S (long) | Cauliflower mosaic virus 35S (CaMV35S) promoter, long variant | strong | Broad, near-constitutive across most dicot tissues and developmental stages; markedly weaker in monocots and inactive in pollen |
| CaMV35S (short) | Cauliflower mosaic virus 35S (CaMV35S) promoter, short variant (~350 bp) | strong | Broad, near-constitutive across dicot leaf, stem, cotyledon, root, and radicle tissue; weaker in monocots and inactive in pollen |
| CBA | CMV early enhancer/chicken beta-actin/SV40 intron (CBA) promoter | strong | Ubiquitous; weak in spinal and brainstem motor neurons |
| CBh | Chicken beta-actin hybrid intron (CBh) promoter | strong | Ubiquitous, including motor neurons (unlike parental CBA) |
| CD11b | Human integrin alphaM (CD11b/ITGAM) promoter | strong | Mature monocytes, macrophages, and neutrophils (myeloid-restricted); shorter promoter fragments have shown ectopic activity in lymphocytes in transgenic mice (Back et al. 1995). |
| CD144 | Human vascular endothelial cadherin (VE-cadherin/CD144) promoter | moderate | Vascular and lymphatic endothelial cells, from early embryonic vasculogenesis (E7.5) through adult quiescent vasculature (Gory et al. 1999; Alva et al. 2006). |
| CD68 | Human CD68 macrophage scavenger receptor gene 5' flanking promoter (2.9 kb) | moderate | Human monocytes and macrophages (myeloid lineage) |
| CD68 (long) | Human CD68 promoter plus first-intron (IVS-1) expression cassette (~3.0 kb) | strong | Human monocytes and macrophages (myeloid lineage) |
| CD68 (short) | Human CD68 macrophage scavenger receptor promoter, short form (~660 bp) | weak | Monocyte/macrophage lineage; specificity is reduced without the downstream first-intron enhancer present in the full-length CD68 cassette |
| CK8e | Synthetic muscle creatine kinase 8 enhanced (CK8e) promoter | strong | Skeletal and cardiac (striated) muscle |
| cMLC2 | Zebrafish cardiac myosin light chain 2 (cmlc2/myl7) promoter | strong | Cardiomyocytes (zebrafish), from early embryonic cardiac development |
| CMV | Human cytomegalovirus immediate-early enhancer/promoter (CMV IE promoter) | strong | Ubiquitous — active across most mammalian cell types and tissues, but expression level varies considerably by cell type and silences over time in liver and skeletal muscle in vivo. |
| CMV+Intron | Human cytomegalovirus immediate-early enhancer/promoter with a chimeric β-globin/immunoglobulin intron | strong | Ubiquitous — active across most mammalian cell types, inherited from the CMV enhancer/promoter component. |
| CNP | Mouse 2',3'-cyclic nucleotide 3'-phosphodiesterase (Cnp) gene promoter | moderate | Oligodendrocytes in the CNS and Schwann cells in the PNS; the originally characterized 4 kb fragment also shows off-target activity in peripheral nerve, testis, and thymus (Gravel et al. 1998; Yuan et al. 2002) |
| Col1a1 | Rat collagen type I alpha-1 (Col1a1) promoter | moderate | Osteoblasts and osteoblast-lineage cells, odontoblasts, and tendon fibroblasts; not active in non-collagen-producing tissues (Bogdanovic et al., 1994) |
| Col2a1 | Mouse collagen type II alpha-1 (Col2a1) promoter | moderate | Chondrocytes in cartilage and the growth plate during endochondral ossification; inactive in fibroblasts (Lefebvre et al., 1996) |
| cTnT | Chicken cardiac troponin T (cTnT) promoter | moderate | Cardiomyocytes; minimal skeletal muscle or non-muscle expression |
| CUP1 | Saccharomyces cerevisiae CUP1 metallothionein promoter | inducible | Not applicable; unicellular S. cerevisiae |
| DmHsp70 | Drosophila melanogaster heat-shock protein 70 (Hsp70) promoter | inducible | Ubiquitous — all tissues respond to heat shock via HSF-dependent HSE activation, and the closely related Hsp70Bb promoter also shows ubiquitous basal (uninduced) activity at standard rearing temperature (Warsinger-Pepe et al. 2023). |
| EF1α | Human eukaryotic translation elongation factor 1 alpha 1 (EEF1A1) promoter | strong | Ubiquitous — active in essentially all human cell types, including dividing and post-mitotic cells and hematopoietic progenitors. |
| EFS | Human elongation factor 1 alpha short form (EFS) promoter | moderate | Ubiquitous |
| EFT-3 | Caenorhabditis elegans translation elongation factor 1-alpha (eft-3/eef-1A.1) promoter | strong | Ubiquitous across somatic tissues; used as the standard somatic reference promoter, paired with separate dedicated promoters (e.g., pie-1) for germline expression in knock-in systems |
| enSM22α | Enhanced smooth muscle 22 alpha (enSM22α) promoter | moderate | Vascular smooth muscle (conductive arterial); enhanced expression relative to the base SM22alpha promoter |
| GAL1 | Saccharomyces cerevisiae galactose-inducible galactokinase 1 (GAL1) promoter | inducible | Not applicable; unicellular S. cerevisiae, active in all cells grown on galactose |
| GAP | Pichia pastoris glyceraldehyde-3-phosphate dehydrogenase (GAP/GAPDH) promoter | strong | Not applicable to tissues - unicellular yeast; active throughout Pichia pastoris cells grown on glucose or glycerol |
| GfaABC1D | Human GFAP-derived minimal astrocyte-specific GfaABC1D promoter | strong | Astrocytes in CNS; off-target expression reported in a subset of cortical neurons, increasing at high AAV titers |
| GFAP | Human glial fibrillary acidic protein (GFAP) promoter | moderate | Astrocytes in CNS; off-target expression reported in a subset of cortical neurons with AAV5 delivery, varying by brain region |
| GPD | Saccharomyces cerevisiae glyceraldehyde-3-phosphate dehydrogenase (GPD/TDH3) promoter | strong | Not applicable; unicellular S. cerevisiae, constitutively active in all cells |
| GRM6 | Mouse metabotropic glutamate receptor 6 (GRM6) minimal enhancer/SV40 basal promoter (0.4 kb) | weak | Retinal ON bipolar cells; some off-target expression in other inner nuclear layer neurons when delivered by AAV |
| GRM6 (long) | Mouse metabotropic glutamate receptor 6 (GRM6) long-form enhancer/promoter (2.2 kb) | strong | Retinal ON bipolar cells — rod bipolar cells in mouse, ON cone bipolar cells in marmoset parafovea and far periphery |