Production of monoclonal antibodies against mammalian Ring1B proteins

The Polycomb group (PcG) genes play a role of transcriptional repressor for long-term maintenance of the Hox cluster gene expression. Recently two str ucturally similar gene products, Ring1A and Ring1B, were identified. Geneti c evidence has indicated that Ring1A has Pc-G properties, however, Ring 1B functions are still unknown. To gain functional insights for Ring1B, we rai sed the mouse monoclonal antibodies (MAbs) against murine Ring1B protein. U sing these antibodies, we have detected specifically mouse, human and monke y Ring1B gene products from whole cell extracts in immunoblot and immunopre cipitation analyses, Immunofluorescent staining by the antibodies has shown that endogenous Ring1B proteins clearly co-localize with Ring1A at the pat tern of diffuse nuclear speckles. Together with their sequence similarity, Ring1B also may function as a Pc-G protein, Finally, we have proposed that the anti-Ring1B would be useful for biochemical and cytological analyses of Ring1B and Pc-G complex.