APA
Federico, Concetta & Gil Alberdi, Laura & Bruno, Francesca & Saccone, Salvatore & D'Amico, Agata Grazia & D'Agata, Velia .Phosphorylated nucleolar Tau protein is related to the neuronal in vitro differentiation.
ISO 690
Federico, Concetta & Gil Alberdi, Laura & Bruno, Francesca & Saccone, Salvatore & D'Amico, Agata Grazia & D'Agata, Velia. Phosphorylated nucleolar Tau protein is related to the neuronal in vitro differentiation.
https://hdl.handle.net/20.500.12080/25998
Resumen:
Tau is a multifunctional protein, originally identified as a cytoplasmic protein associated with
microtubules. It is codified by the MAPT gene, and the alternative splicing, in the neuronal cells,
results in six different isoforms. Tau was subsequently observed in the cell nucleus, where its function
is not yet clearly understood. Here, we studied the MAPT gene and the cellular localization of the AT8
and Tau-1 epitopes of Tau protein, in the SK-N-BE cell line, which differentiates in neuronal-like cells
after retinoic acid treatment. These epitopes correspond to the phosphorylated Ser202/Thr205 and
unphosphorylated Pro189/Gly207 amino acid residues, respectively, possibly involved in
conformational changes of the protein. Our results demonstrated the presence of the smaller Tau
isoform (352 amino acids), whose amount increases in differentiated SK-N-BE cells, with Tau-1/AT8
nuclear distribution related to the differentiation process. Tau-1 showed a spot-like nucleolar
localization, in both replicative and differentiated cells, while AT8 was only detected in the
differentiated cells, diffusely occupying the entire nucleolar region. Moreover, in the replicative cells
exposed to actinomycin-D, AT8 and Tau-1 move to the nucleolar periphery and colocalize, in few
spots, with the upstream binding transcription factor (UBTF). Our results, also obtained with
lymphocytes exposed to the mitogenic compound phytohaemagglutinin, indicate the AT8 epitope of
Tau as a marker of neuronal cell differentiation, whose presence in the nucleolus appears to be related
to rDNA transcriptional inactivation.