Colocalization of doublecortin with the microtubules: an ex vivo colocalization study of mutant doublecortin.

Doublecortin (DCX) plays an important role in neuronal migration and development, and the participation of DCX in neuronal migration has been demonstrated by intensive mutational analysis for patients with X-linked or sporadic lissencephaly, and/or subcortical laminar heterotopia. Although a previous search for protein similarity showed that DCX has a region homologous to the putative Ca(2+)/calmodulin-dependent protein kinase, the function of the DCX gene (DCX) has remained unknown. We show here that mouse DCX colocalizes with the microtubules and provide evidence that its conformational structure is important for its subcellular localization by means of mutant doublecortin expression study. The results of our study may suggest that the cytoskeleton involving DCX mediates the neuronal migration during brain development.