| Targeta | Multiplexb | Quad. Proofc | Transcription Assayd | Maxmium Effecte | Controlsf | Ref. |
|---|---|---|---|---|---|---|
| human insulin gene, -363, plasmid | (G9A2T2C)n, intra- or inter-molecular G4 | EMSA, DMS FP | in vivo, HeLa cells, luciferase | -80% with Pur-1 | mut. G4 -, multi-mut. G4 +, Pur-1 expression | 109 |
| syn. | G4 RNA? | n.s. | in vitro, T7 RNA pol. + GTP only, PAGE | +100% termination @ 13-14 nt. | 7-deaza- GTP | 110 |
| human c-myc promoter, chromosome | 22mer G18A2T2, G4' | n.s. | in vivo, Ramos cells, proliferation, G4' ODN, media | -70% @ 100 nM G4 ODN, (-55% @ 100 nM ss G-ODN) | random ODN | 111 |
| human c-myc promoter, -115 P1, plasmid or chromosome | 27mer G20A4T3, stimulated by TMPyP4, “chair” G4' | DMS FP, TMPyP4 UV FP, Taq DNA pol. stop | in vivo, HeLa cells, luciferase or Ramos cells, RT-PCR | +200% chair mut. | TmPyP2, alternative G4 - mut., CA46 cells | 112 |
a Target information is indicated as gene name, site, and whether located on an extrachromosomal DNA (e.g., plasmid) or on a chromosome. Syn., synthetic target.
b Quadruplex information is indicated as length of the quadruplex-forming region, composition or sequence, auxiliary compounds (“stabilized with...”), and quadruplex form. TMPyP4, cationic porphyrin.
c Assays used to demonstrate quadruplex formation include electrophoretic mobility shift assays (EMSA), footprinting (FP) with dimethyl sulfate (DMS) or ultraviolet radiation (UV), and polymerase (pol.) stop assays. Data not shown (n.s.).
d Transcription assay information is presented as assay type for in vitro studies and as cell type, template, and assay type for in vivo studies. PAGE, polyacrylamide gel electrophoresis. RT-PCR, reverse transcriptase PCR.
e Maximum effect of quadruplex on transcription. Minus and plus sign preceding percentage effect indicate quadruplex-dependent transcription inhibition and stimulation, respectively. Abbreviations include nucleotide (nt.), single-stranded (ss), and mutation (mut.). Unexpected or unusual findings are indicated in parentheses.
f Controls used to demonstrate specificity of triplex effects on transcription. G4- and G4+ refer to mutations that either disrupt or promote G4 formation.
From: Do DNA Triple Helices or Quadruplexes Have a Role in Transcription?
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