This domain (Cnn_1N) is a short conserved motif found in the N-terminal of a group of centrosome or spindle pole body (SPB) associated proteins, including Mto1 and Pcp1 from S. pombe [, ], centrosomin from flies [, ]and myomegalin/CDK5RAP2 from mammals [, ]. In Drosophila, centrosomin (Cnn) is an essential mitotic centrosome component required for assembly of all other known pericentriolar matrix (PCM) proteins to achieve microtubule-organising activity at mitosis. The Cnn_1N domain (motif 1 of Cnn) is necessary for proper recruitment of gamma-tubulin, D-TACC (the homologue of vertebrate transforming acidic coiled-coil proteins [TACC]), and Minispindles (Msps) to embryonic centrosomes but is not required for assembly of other centrosome components including Aurora A kinase and CP60 in Drosophila [].
