Topoisomerase I Binding, Arginine/Serine Rich (TOPORS)

TOPORS is rich in serine and arginine and contains a leucine zipper domain, 2 PEST sequences, a central basic domain containing 2 potential bipartite nuclear localization signals, and 2 C-terminal PEST sequences.

The deduced 1,045-amino acid protein has a calculated molecular mass of 119 kD. TOPORS contains an N-terminal PEST sequence, followed by a C3H4-type RING finger domain, a leucine zipper coiled-coil region, 2 PEST sequences, a nuclear localization signal, and 2 C-terminal PEST sequences. Northern blot analysis detected a 3.8-kb transcript in brain, kidney, liver, lung, spleen, pancreas, and skeletal muscle, and a 3.6-kb transcript in heart and lung. Highest expression of TOPORS was in lung.