This family represents a conserved region approximately 60 residues long within the eukaryotic targeting protein for Xklp2 (TPX2). Xklp2 is a kinesin-like protein localized on centrosomes throughout the cell cycle and on spindle pole microtubules during metaphase. In Xenopus, it has been shown that Xklp2 protein is required for centrosome separation and maintenance of spindle bi-polarity. TPX2 is a microtubule-associated protein that mediates the binding of the C-terminal domain of Xklp2 to microtubules. It is phosphorylated during mitosis in a microtubule-dependent way.