A novel murine gene encoding a 216-kDa protein is related to a mitotic checkpoint regulator previously identified in Aspergillus nidulans.

We describe the isolation and characterization of a novel mouse gene, tsg24, which displays striking sequence similarities to the Aspergillus nidulans bimE gene. The bimE gene has been shown to be a mitotic checkpoint regulator, negatively regulating entry into mitosis in A. nidulans. The tsg24 gene was found to contain a long open reading frame of 1944 amino acids, encoding a polypeptide with a calculated molecular mass of 216,087 Da. We have developed an antibody directed against the product of the tsg24 gene and identified a protein with a molecular mass of approximately 200 kDa. This protein was found to be uniformly expressed throughout interphase of the cell cycle, whereas the level of this protein was lower in protein extracts prepared from mitotic cells.