The chicken urokinase-type plasminogen activator gene.

The chicken urokinase-type plasminogen activator (uPA) cDNA and gene have been isolated and the complete nucleotide sequence of each established. cDNA sequence and Northern blot RNA analysis indicate that the chicken uPA mRNA is approximately 2500 nucleotides in size and contains a large 3'-noncoding region (998 nucleotides). The predicted amino acid sequence of the chicken uPA primary translation product (434 residues) suggests a domain architecture comparable to the mammalian uPA proteins with the form: (i) signal peptide, (ii) growth factor domain (GF), (iii) kringle domain (K), and (iv) serine protease domain (C). The overall sequence identity between the chicken and human proteins is 43.1%, with 56.3, 48.5, and 45.6% identity in the GF, K, and C domains, respectively. The chicken uPA gene is similar to the mammalian uPA genes in both size (8158 base pairs between transcription initiation and polyadenylation sites) and organization (11 exons). However, the sequence of the chicken uPA gene is similar to the mammalian uPA genes only within the protein-coding portions of exons. The transcription initiation site is flanked by a remarkably G/C-rich region (77% between nucleotides -1 and -300) which contains a TATA element and several potential transcription factor Spl-binding sites. The promoter region also contains several repeat elements, including two 11-nucleotide repeats that encompass six potential transcription factor AP-2-binding sites. This work provides a foundation for exploring the mechanism(s) by which protein-tyrosine kinase pp60v-src and protein kinase C modulate uPA gene transcription.