MOLECULAR-CLONING AND CHARACTERIZATION OF THE MOUSE TAG7 GENE ENCODING A NOVEL CYTOKINE

Cloning of the mouse tag7 gene encoding a novel cytokine is described. The Tag7 protein consists of 182 amino acids. Genomic organization of the tag7 gene and its promoter region remind those of the genes of th e tumor necrosis factor locus, although the tag7 gene is not linked to this locus. The gene is located on chromosome 7 at the area that corr esponds to band 7A3, which has genetic linkage with lupus-like disease in mouse models, tag7 transcription is essential for lymphoid organs, It is also detected in certain areas of lungs, brain, and intestine a nd in some tumors. Tag7 protein is detectable in both cell-associated and soluble forms. The soluble form of Tag7 triggers apoptosis in mous e L929 cells in vitro and does not involve NF-kappa B activation. The relationship between Tag7 and tumor necrosis factor family of ligands is discussed.