Identification of a functional destruction box in the Xenopus laevis aurora-A kinase pEg2

Like for all aurora-A kinases, the Xenopus pEg2 kinase level peaks in G(2)/ M and is hardly detectable in G, cells, suggesting that the protein is degr aded upon exit from mitosis as reported for the human aurora-A kinase. We i dentified for the first time a sequence RxxL in the C-terminal end of the k inase catalytic domain. Mutation of this sequence RxxL to RxxI suppresses t he ubiquitination of the protein as well as its degradation. The sequence R xxL corresponding to the pEg2 functional destruction box has been conserved throughout evolution in all aurora kinases including aurora-A, -B and -C. (C) 2001 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.