Molecular identification of a murine ubiquitin/60S ribosomal fusion protein and expression study in mouse kidney

We have isolated and sequenced a 500-bp cDNA clone which is the murine homologue of a ubiquitin/60S ribosomal fusion protein. The cDNA and the deduced amino acid sequence are highly conserved. Northern blotting demonstrates constitutive expression in a mouse renal epithelial cell line and in mouse kidneys. Upon stimulation with interferon-gamma or phorbol esters, the expression is not changed, contrasting with the stimulation seen for polyubiquitin. Expression of the 16-kD ubiquitin/60S protein is also demonstrated in mouse epithelial cells.