NUCLEOLAR LOCALIZATION OF THE MICROTUBULE-ASSOCIATED PROTEIN-TAU IN NEUROBLASTOMAS USING SENSE AND ANTISENSE TRANSFECTION STRATEGIES

The Tau-l monoclonal antibody was localized to the nucleolus of interp hase cells and the nucleolar organizing regions (NORs) of acrocentric chromosomes in cultured human cells. Putative nucleolar and NOR tau wa s found in CG neuroblastoma cells which contain nucleolar tau and litt le cytoplasmic tau. To further establish the presence of tau in the nu cleolus of these cells, sense and anti-sense transfection strategies w ere used. CG neuroblastoma cells were transfected with tau sense cDNA and immunostained with Tau-l. Cytoplasmic Tau-l staining was greatly i ncreased in CG cells which contain very little endogenous cytoplasmic tau. Nucleolar Tau-l staining was also increased in certain CG cells i ndicating an increase in nucleolar tau in a subset of transfected cell s. CG cells were also transfected with tau anti-sense cDNA which aboli shed Tau-l staining in the nucleolus. These results contribute to a gr owing body of evidence defining tan as a multifunctional protein found in both the cytoplasm and nucleoli of primate cells. (C) 1997 Wiiey-L iss, Inc.