AIM-1 - A MAMMALIAN MIDBODY-ASSOCIATED PROTEIN REQUIRED FOR CYTOKINESIS

Mitosis is a highly coordinated process that assures the fidelity of c hromosome segregation, Errors in this process result in aneuploidy whi ch can lead to cell death or oncogenesis, In this paper we describe a putative mammalian protein kinase, AIM-1 (Aurora and Ipl1-like midbody -associated protein), related to Drosophila Aurora and Saccharomyces c erevisiae Ipl1, both of which are required for chromosome segregation. AIM-1 message and protein accumulate at G(2)/M phase, The protein loc alizes at the equator of central spindles during late anaphase and at the midbody during telophase and cytokinesis, Overexpression of kinase -inactive AIM-1 disrupts cleavage furrow formation without affecting n uclear division, Furthermore, cytokinesis frequently fails, resulting in cell polyploidy and subsequent cell death, These results strongly s uggest that AIM-1 is required for proper progression of cytokinesis in mammalian cells.