Human tenascin gene. Structure of the 5'-region, identification, and characterization of the transcription regulatory sequences.
This report describes the genomic organization of the 5'-region of the human tenascin-C (TN) gene and the functional characterization of its promoter. Approximately 2300 base pairs of the TN gene 5'-flanking region have been cloned and sequenced. This genomic region contains several potential binding sites for transcription factors. By primer extension and S1 nuclease analysis we have localized the transcription start site. The first exon of the TN gene (179 base pairs long) is present in the two major TN transcripts, showing that the expression of these two mRNAs is regulated by a single promoter. The 220 bases upstream to the transcription start site are equally active in directing the expression of chloramphenicol acetyltransferase (CAT) reporter gene in TN producer and nonproducer cells. Using deletion fragments of the human 5'-flanking region we have shown the presence of putative "silencer" elements in the -220 to -2300 region active in both TN producer and nonproducer cell lines. Furthermore, we have demonstrated that the selective transcription in TN producing cells requires the presence of a 1.3-kilobase portion of the TN gene intron 1 in the CAT expression vectors. These findings indicate that complex mechanisms control the transcriptional regulation of TN gene.
Gherzi
R
R
Laboratory of Cell Biology, Instituto Nazionale per la Ricerca sul Cancro, Genova, Italy.
Carnemolla
B
B
Siri
A
A
Ponassi
M
M
Balza
E
E
Zardi
L
L
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D015816:Cell Adhesion Molecules, Neuronal / Q000096:biosynthesis / Q000235:genetics*; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000096:biosynthesis; D017931:DNA Primers; D016326:Extracellular Matrix Proteins / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D005809:Genes, Regulator; D015186:Hominidae / Q000235:genetics*; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000235:genetics; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000096:biosynthesis; D012045:Regulatory Sequences, Nucleic Acid; D015183:Restriction Mapping; D019063:Tenascin; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic; D014162:Transfection; D001616:beta-Galactosidase / Q000096:biosynthesis
D015816:Cell Adhesion Molecules, Neuronal; D017931:DNA Primers; D016326:Extracellular Matrix Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger; D019063:Tenascin; D014157:Transcription Factors; D015500:Chloramphenicol O-Acetyltransferase; D001616:beta-Galactosidase