title: [Identification of AP1 cis-element and transcriptional effect on cytokeratin 13 gene expression].
abstract: OBJECTIVE
  To identify the type of CTGAATCA from -nt.199 to -nt.192 of the cytokeratin 13(CK13) gene 5' flanking region and determine its transcriptional effect on CK13 gene expression.
  
  
  METHODS
  The CAT systems were used to assess the effects of different motifs of CK13 gene 5' flanking region on transcription. The clones of pCAT-enhancer with the total length, -nt.207 to +nt.63 and the same length of -nt.207 to +nt.63, but the T, G of -nt.198, -nt.197 being changed to A, T of the CK13 gene 5' flanking region, were constructed and transferred to HeLa cells with the help of lipofectin. Then work was done to detect the instant CAT expression of different clones and evaluate the effects of CTGAATCA of the 5' flanking region on CK13 gene expression. The type of the cis-element of CTGAATCA was identified with electrophoretic mobility shift assay (EMSA) and competition-EMSA.
  
  
  RESULTS
  CTGAATCA in the CK13 gene 5' flanking region is an AP1 cis-element by EMSA and competition-EMSA, it promotes CK13 gene expression.
  
  
  CONCLUSIONS
  CTGAATCA from -nt.199 to nt.192 of the CK13 gene 5' flanking region is an AP1 reaction element, not a cAMP reaction element. It promotes transcriptional activity of CK13 gene 5' flanking region.
authors.affiliation: Department of Otorhinolaryngology, Xiangya Hospital, Central South University, Changsha, Hunan, 410008 P. R. China. Lingongbiao@Sohu.com
authors.forename: Gongbiao
authors.initials: G
authors.lastname: Lin
authors.forename: Jianyun
authors.initials: J
authors.lastname: Xiao
authors.forename: Suping
authors.initials: S
authors.lastname: Zhao
authors.forename: Yongquan
authors.initials: Y
authors.lastname: Tian
authors.forename: Chenglong
authors.initials: C
authors.lastname: Wang
authors.forename: Yuanzheng
authors.initials: Y
authors.lastname: Qiu
mesh_terms: D024506:5' Flanking Region / Q000235:genetics; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D001667:Binding, Competitive; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics / Q000378:metabolism; D004247:DNA / Q000235:genetics / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006801:Humans; D007633:Keratins / Q000235:genetics*; D009154:Mutation; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics*; D014162:Transfection
chemical_list: D011993:Recombinant Fusion Proteins; D018808:Transcription Factor AP-1; D007633:Keratins; D004247:DNA; D015500:Chloramphenicol O-Acetyltransferase