Isolation and characterization of BART-1: A novel balloon angioplasty responsive transcript in rat carotid arteries.

In previous studies, differential display analysis of balloon angioplasty-damaged rat carotid arteries identified a temporally expressed partial cDNA termed RC9. This message is undetectable in undamaged vessels, reaches maximal levels 3 days post-procedure, and reduces to half-maximal expression by 14 days post angioplasty. Using RC9 to screen a cDNA library, we now report the isolation and characterization of a full-length clone, termed BART-1. BART-1 is 98% homologous to RC9 and shows the same mRNA expression pattern as RC9 in rat carotid arteries subject to balloon angioplasty. Northern analysis of various rat tissues reveals tissue specificity and possible differential processing. Neither the nucleic acid nor amino acid sequences demonstrate similarity to previously reported expressed sequences. Predicted amino acid analysis reveals two strongly hydrophilic and one hydrophobic region, suggesting a type II integral membrane protein. The cDNA sequence hybridized to genomic DNA from a variety of species, suggesting evolutionary conservation. Thus, BART-1 mRNA appears to represent an inducible, tissue-specific transcript encoding a putative integral membrane protein transiently expressed in response to vascular trauma.