Cloning and characterization of a novel human ninein protein that interacts with the glycogen synthase kinase 3β

Using human glycogen synthase kinase 3 beta (GSK-3 beta) as bait in the yeast two-hybrid system, we identified a novel human centrosome associated protein, hNinein. When the full length cDNA of hNinein was sequenced, it showed that an open reading frame encoded a protein consisting of 2047 amino acids with a predicted molecular mass of 239 kDa. The features of this protein include a potential GTP binding site, a large coiled-coil domain together with four leucine zipper domains and a GSK-3 beta binding site. Fluorescence microscopy experiment showed that hNinein is localized in the pericentriolar matrix of the centrosome. In addition, hNinein also showed to react with centrosomal autoantibody sera. Our findings suggest that hNinein may be involved in the formation of centrosome matrix and interacts with the GSK3 beta, implying that it may also be regulated by GSK-3 beta phosphorylation signaling. (C) 2000 Elsevier Science B.V. All rights reserved.