TATA box-independent transcription of the human tissue plasminogen activator gene initiates within a sequence conserved in related genes.
Transcription of the human tissue-type plasminogen activator (tPA) gene has been reported to initiate from a single site proximal to a TATA box motif [1985, J. Biol. Chem. 260, 11223-11230]. In this study, we utilized primer extension analysis to evaluate the tPA mRNA start site in phorbol-12-myristate 13-acetate (PMA) induced WI-38 human lung fibroblast cells. Whilst some tPA mRNA initiated from the predicted TATA-proximal location (+1), a 10-fold greater proportion of tPA mRNA transcripts initiated 110 bases downstream from a sequence conserved and utilized as the TATA-independent transcription start site in the rodent tPA genes. Moreover, the transfection and expression in different cell types of a cosmid containing the entire human tPA gene resulted in utilization of the same downstream (+110) start site. We propose that this, rather than the previously published position, is the major transcriptional initiation point for the human tPA gene. A core sequence (5'-CAGAGCTG-3') was identified which is common to the TATA-independent mRNA start sites of the human, mouse and rat tPA genes, and which demonstrates only partial similarity to sequences found at the initiation point of other TATA-independent genes.
Henderson
B R
BR
Department of Medicine, University of Sydney, Westmead Hospital, NSW, Australia.
Sleigh
M J
MJ
D000595:Amino Acid Sequence; D015152:Blotting, Northern; D002460:Cell Line; D005786:Gene Expression Regulation / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D016385:TATA Box / Q000235:genetics*; D010959:Tissue Plasminogen Activator / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics*
D012333:RNA, Messenger; D010959:Tissue Plasminogen Activator