Human Tenascin Gene

doi:10.1074/jbc.270.7.3429

Human Tenascin Gene

STRUCTURE OF THE 5′-REGION, IDENTIFICATION, AND CHARACTERIZATION OF THE TRANSCRIPTION REGULATORY SEQUENCES (*)

From the Laboratory of Cell Biology, Istituto Nazionale per la Ricerca sul Cancro, Viale Benedetto XV, 10, 16132 Genova, Italy

^§ To whom correspondence should be addressed:
Laboratory of Cell Biology, Istituto Nazionale per la Ricerca sul Cancro, Viale Benedetto XV, 10, 16132 Genova, Italy.
Tel.: 3910-352855/3534901; Fax: 3910-352855.

Abstract

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.

Footnotes

↵* This study was supported in part by AIRC funds and by Consiglio Nazionale per le Ricerche: Progetto Finalizzato “Applicazioni Cliniche della Ricerca Oncologica.” The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EMBL Data Bank with accession number(s) X78563[GenBank], X78564[GenBank], X78565[GenBank], and X78566[GenBank].
↵¹ The abbreviations used are:

TN

tenascin-C

bp

base pair(s)

kb

kilobase(s)

CAT

chloramphenicol acetyltransferase

PCR

polymerase chain reaction.
- Received October 31, 1994.