title: Study of G-quadruplexes in the STAT3 gene using electrospray ionization mass spectrometry.
abstract: As a key signal transducer and transcription activator, STAT3 plays a very important role in many cell processes. We found that there were many G-rich sequences existing in the STAT3 gene including its promoter, intron, exon and 3'-flanking regions. These G-rich tracts can form G-quadruplexes under near physiological conditions. In this research, we systemically studied the G-quadruplexes in the STAT3 gene at a whole gene scale for the first time.
  
  
  
  In this research, the formation of G-quadruplexes in the STAT3 gene was probed by electrospray ionization mass spectrometry (ESI-MS) and circular dichroism (CD). Their structures were constructed and refined by a molecular modeling method. We also used ESI-MS to study the recognition of the G-quadruplexes in the promoter of the STAT3 gene by flexible molecules which do not have a planar core like the other common quadruplex ligands.
  
  
  
  The results based on ESI-MS suggested that the G-quadruplexes in the promoter of the STAT3 gene formed and were further recognized by some small molecules.
  
  
  
  Our research proved that the G-rich sequences in the STAT3 gene could form G-quadruplexes under near physiological conditions. This provides a promising target to study the regulation of cell signal transduction in vivo and drug design that aims to target STAT3 G-quadruplexes. Copyright © 2016 John Wiley & Sons, Ltd.
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.|Beijing National Day School, Beijing, 100871, China.
authors.forename: Sen
authors.initials: S
authors.lastname: Lin
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
authors.forename: Haitao
authors.initials: H
authors.lastname: Long
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China.
authors.forename: Gu
authors.initials: G
authors.lastname: Yuan
mesh_terms: D002942:Circular Dichroism; D018983:DNA Footprinting / Q000379:methods; D054856:G-Quadruplexes; D006801:Humans; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D050796:STAT3 Transcription Factor / Q000235:genetics*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D050796:STAT3 Transcription Factor; C494086:STAT3 protein, human