Open AccessCharacterization of the promoter for the mouse α3 integrin gene
Author(s) -
Kato Takumi,
Katabami Kouji,
Takatsuki Hironori,
Han Seon Ae,
Takeuchi Kenichi,
Irimura Tatsuro,
Tsuji Tsutomu
Publication year - 2002
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1046/j.1432-1033.2002.03146.x
Subject(s) - microbiology and biotechnology , biology , promoter , caat box , gene , transcription (linguistics) , transcription factor , integrin, beta 6 , tata box , transfection , gene isoform , 5' flanking region , gene expression , genetics , integrin alpha m , linguistics , philosophy , flow cytometry
The α3β1 integrin is an adhesion receptor for extracellular matrix proteins including isoforms of laminin, and the changes of its expression level in various cancer cells are thought to cause their malignant phenotypes. We have cloned an approximately 4 kb DNA fragment of the 5′‐flanking region of the murine α3 integrin gene and analyzed its promoter activity. Transfection of MKN1 gastric carcinoma cells with serially truncated segments of the 5′‐flanking region linked to a luciferase gene indicated that a 537‐bp Sal I/ Sac I fragment upstream of exon 1 was sufficient to promote high level gene expression. By 5′‐rapid amplification of cDNA ends (5′‐RACE) using a cap site‐labeled cDNA library, we determined one major and one minor transcription start sites in this region. The murine α3 integrin gene was found to contain a CCAAT box, but to lack a TATA box. Luciferase assay following transfection with a series of deletion constructs of the Sal I/ Sac I fragment revealed that the sequence between positions −260 and −119 bp (relative to the major transcription start site) is required for efficient transcription in gastric carcinoma cells. The sequence analysis of this segment showed the presence of several consensus sequences for transcription factors including Ets, GATA and MyoD/E‐box binding factors. The introduction of mutation in one of the Ets‐binding sequences greatly decreased its promoter activity, suggesting that the transcription of the α3 integrin gene in these cells is regulated by the Ets‐family of transcription factors.