Cloning, genomic organization, and chromosomal localization of the Scya5 gene encoding the murine chemokine RANTES.

RANTES is a member of the C-C subfamily of chemokines that functions as a proinflammatory chemoattractant for CD4+ T cells, monocytes, and eosinophils, and as an activator of basophils to release histamine. Like other members of the chemokine superfamily, RANTES has been implicated in a number of chronic inflammatory and autoimmune processes based on its function and its pattern of regulation. To begin study of the transcriptional regulation of RANTES, we have determined the genomic organization of the gene encoding the small inducible cytokine A5 (Scya5) and performed an initial analysis of its promoter elements. The Scya5 gene is located on chromosome 11. By Southern blot, it is a single-copy gene approximately 4.5 kb long composed of 3 exons. This chromosomal localization and pattern of genomic organization is conserved among the other C-C subfamily of chemokines. Primer extension analysis was used to identify the transcriptional initiation site that is located 27 bp downstream of a typical TATAA box. Sequence analysis of 1040 bp 5' to the start site of the Scya5 gene revealed a number of regulatory motifs that are also shared among the chemokine family including a PU.1 box, a NF-kappa B, and an IFN regulatory factor-1 response element. This region of genomic DNA was also cloned into a luciferase reporter vector. Transfection of this reporter construct into murine proximal tubular cells reveals that TNF-alpha can induce a transcriptional activation of the gene, as would be predicted from the rise in mRNA transcripts encoding RANTES in cells stimulated with TNF-alpha.