Table 1. In vitro RGA systems for the screening of EcR-USP ligands.
| Host cells | Organism and cell lines | Transfected receptor genes | EcRE | Reporter gene | Types of test compounds | Ref. |
|---|---|---|---|---|---|---|
| Insect cells* | Drosophila melanogaster Kc | — | Dm hsp27 promoter | Luc | 20E, α-ecdysone | 55) |
| D. melanogaster Kc | — | Dm hsp27 promoter | Luc | 3,5-di-tert-butyl-4-hydroxy-N-isobutyl-benzamide (DTBHIB) | 56) | |
| D. melanogaster Kc | — | Dm hsp27 promoter | Luc | Diacylhydrazine (DAH) compounds | 57) | |
| D. melanogaster Schneider 2 (S2) | — | Dm hsp27 | lacZ | Cucurbitacins | 134) | |
| EcRE | ||||||
| D. melanogaster Schneider SL2 | — | Dm hsp27 | Luc | Insect and plant ecdysteroids | 139) | |
| EcRE | ||||||
| Spodoptera frugiperda Sf9 | — | Dm hsp27 | Luc | 20E, ponasterone A (pon A), chromafenozide | 67) | |
| EcRE | ||||||
| D. melanogaster Kc | — | Dm hsp27 | Luc | 20E, pon A, chromafenozide | 67) | |
| EcRE | ||||||
| Bombyx mori Bm5 | — | Dm hsp27 | CAT | Plant compounds | 58) | |
| EcRE | GFP | DAH library | ||||
| S. frugiperda Sf9 | CfEcR | Dm hsp27 | CAT | RG-102240 | 68) | |
| EcRE | ||||||
| Lymantria dispar (Ld652Y) | CfEcR | GAL4 RE (two-hybrid) | CAT | RG-102240 | 68) | |
| MmRXR | GFP | |||||
| B. mori Bm5 | — | Dm hsp27 | GFP | DAHs | 70) | |
| EcRE | ||||||
| D. melanogaster S2 | — | Dm hsp27 | Luc | Chromafenozide | 69) | |
| EcRE | Methoxyfenozide | |||||
| B. mori Bm5 | — | Dm hsp27 | Luc | Chromafenozide | 69) | |
| EcRE | Methoxyfenozide | |||||
| Anthonomus grandis BRL-AG-3A | — | Dm hsp27 | Luc | DAHs | 76) | |
| BRL-AG-3C | EcRE | GFP | ||||
| Leptinotarsa decemlineata BCRL-Lepd-SL1 | — | Dm hsp27 | Luc | DAHs | 76) | |
| EcRE | GFP | |||||
| D. melanogaster S2 | — | Dm hsp27 | CAT | DAHs, acylaminoketone (AAK) analogs, tetrahydroquinoline (THQ) compounds, piperidiamine analogs | 80) | |
| EcRE | Luc | |||||
| B. mori Bm5 | — | Dm hsp27 | GFP | DAHs, AAK analogs, THQs | 71) | |
| EcRE | ||||||
| S. littoralis Sl2, Slj2b | — | Dm hsp27 | Luc | DAHs, AAK analogs, THQs | 71) | |
| EcRE | ||||||
| S. frugiperda Sf9 | — | Dm hsp27 | Luc | Non-steroidal compounds | 78) | |
| EcRE | ||||||
| L. decemlineata | — | Dm hsp27 | Luc | DAHs | 77) | |
| BCRL-Lepd-SL1 | EcRE | |||||
| D. melanogaster S2 | — | Dm hsp27 | Luc | Ecdysteroids | 135) | |
| EcRE | ||||||
| B. mori Bm5 | — | Dm hsp27 | Luc | Ecdysteroids | 135) | |
| EcRE | ||||||
| S. frugiperda Sf9 | — | Dm hsp27 | Luc | N-tert-butylphenyl thenoylhydrazide compounds | 140) | |
| EcRE | ||||||
| D. melanogaster S2 | — | Dm hsp27 | Luc | Compounds registered in Maybridge database | 79) | |
| EcRE | ||||||
| B. mori Bm5 | — | Dm hsp27 | Luc | Compounds registered in Maybridge database | 79) | |
| EcRE | ||||||
| Mammalian cells | Cricetulus griseus | VgEcR | E/GRE | lacZ | Phytochemicals | 90) |
| CHO | HsRXR | |||||
| Mus musculus | AaEcR | GAL4 RE (two-hybrid) | Luc | THQs | 3) | |
| NIH 3T3 | MmRXR | |||||
| Mammalian cells | Homo sapiens | BmEcR | Dm hsp27 EcRE | β-gal | AAKs | 72) |
| HEK293 | ||||||
| H. sapiens | BmEcR | Dm hsp27 EcRE | β-gal | AAKs | 60) | |
| HEK293 | ||||||
| C. griseus | CfEcR | GAL4 RE (two-hybrid) | Luc | AAKs | 60) | |
| CHO | HsRXR-LmRXR chimera | |||||
| M. musculus | CfEcR | GAL4 RE (two-hybrid) | Luc | DAHs, THQs | 61) | |
| NIH 3T3 | LmRXR | |||||
| DmTai | ||||||
| M. musculus | AaEcR | GAL4 RE (two-hybrid) | Luc | THQs | 4) | |
| NIH 3T3 | CfEcR | |||||
| DmEcR | ||||||
| MsEcR | ||||||
| BmEcR | ||||||
| LmEcR | ||||||
| TmEcR | ||||||
| AmaEcR | ||||||
| HsRXR | ||||||
| M. musculus | AaEcR | GAL4 RE (two-hybrid) | Luc | Natural and semi-synthetic ecdysteroids (hydroxylation) | 62) | |
| NIH 3T3 | CfEcR | |||||
| DmEcR | ||||||
| MsEcR | ||||||
| BmEcR | ||||||
| TmEcR | ||||||
| AmaEcR | ||||||
| BaEcR | ||||||
| NcEcR | ||||||
| HsRXR | ||||||
| M. musculus | VgEcR | E/GRE | Luc | Natural and semi-synthetic ecdysteroids (hydroxylation) | 62) | |
| NIH 3T3 | HsRXR | |||||
| M. musculus | AaEcR | GAL4 RE (two-hybrid) | Luc | Natural and semi-synthetic ecdysteroids (alkylation) | 63) | |
| NIH 3T3 | CfEcR | |||||
| DmEcR HsRXR-LmRXR chimera | ||||||
| M. musculus | VgEcR | E/GRE | Luc | Natural and semi-synthetic ecdysteroids (alkylation) | 63) | |
| NIH 3T3 | HsRXR | |||||
| H. sapiens | BmaEcR | GAL4 RE (two-hybrid) | Luc | Steroidal ecdysones, DAHs | 64) | |
| HEK293 | HsRXR | |||||
| Yeast | Saccharomyces cerevisiae | CfEcR-CfUSP | Dm hsp27 EcRE | β-gal | Nonsteroidal ecdysone agonists | 85) |
| HsRXR | ||||||
| MmGRIP1 | ||||||
| S. cerevisiae | AaEcR-AaUSP | Dm hsp27 EcRE | β-gal | Ecdysteroids, nonsteroidal ecdysone agonists | 84) | |
| DmUSP | ||||||
| CfUSP | ||||||
| HsRXR | ||||||
| MmGRIP1 | ||||||
| S. cerevisiae | DmEcR-DmUSP | IR0 | β-gal | Ecdysteroids, DAHs, THQ | 87) | |
| CsEcR-CsUSP | DR2 | |||||
| LdEcR-LdUSP | DR4 | |||||
| DmTai |
Abbreviations Aa: Aedes aegypti; Ama: Amblyomma americanum; Ba: Bemisia argentifolii; Bm: Bombyx mori; Bma: Brugia malayi; Cf: Choristoneura fumiferana; Cs: Chilo suppressalis; Dm: Drosophila melanogaster; E/GRE: ecdysone/glucocorticoid responsive element (hybrid RE); Hs: Homo sapiens; Lm: Locusta migratoria; Ms: Manduca sexta; Nc: Nephotettix cincticeps; Tc: Tribolium castaneum; Tm: Tenebrio molitor; Mm: Mus musculus; CHO; Chinese hamster ovary; GAL4 RE: DNA element for binding of the GAL4 DNA-binding domain (DBD); VgEcR: hybrid of D. melanogaster EcR carrying modified DBD and VP16 AD that recognizes an E/GRE *Reporter gene assays in insect cells expressing endogenous EcR and USP. Only the reporter plasmid was introduced.