Novel mammalian kinase related to yeast and fly chromosome segregation regulators is exclusively expressed in the germline

Since kinases play important roles in regulating both mitotic and meiotic cell cycles in a variety of organisms, we sought to clone novel kinases that might regulate germ cell development in mammals. One of the kinases we identified, termed IAK3, is a member of a newly emerging subfamily of the serine/threonine kinase superfamily and mapped to mouse Chromosome 7. This kinase is related to genes identified in yeast and Drosophila which are regulators of chromosome segregation and to another mammalian kinase, IAK1, which is a new component of the centrosome and mitotic spindle. IAK3 transcripts are uniquely expressed in germ cells and are undetectable in proliferating somatic cells. Thus IAK3 may be a regulator of microtubule dynamics and/or chromosome segregation in the germline.