INVESTIGADORES
VALACCO Maria Pia
congresos y reuniones científicas
Título:
Nucleo-cytoplasmic localization of p8, cell cycle and signal transduction pathways.
Autor/es:
VALACCO, MP, C.VARONE, J. IOVANNA, AND S.MORENO
Lugar:
Bariloche, Argentina
Reunión:
Congreso; XXXIX Reunión Anual SAIB; 2003
Institución organizadora:
Sociedad Argentina de Investigacion Bioquimica
Resumen:
p8, an 8 kDa protein was first identified by its induction during the acute phase of pancreatitis. Its mRNA is expressed in cell lines in response to stress and mitogenic factors. With immuno-cytochemistry, we found that p8 presents nuclear localization in sub-confluent cells, but it localizes in the cytoplasm of confluent cells. Further experiments have shown that nuclear import is energy dependent and that the export of p8 does not involve the CRM1 transporter. Different experiments with cycloheximide suggest that the protein found in the cytoplasm is the result of a de novo protein synthesis, and not of the export of nuclear p8. The objective of this work is to study the sub-cellular localization of the protein along the stages of the cell cycle with immunocytochemistry. Different strategies, such as serum deprivation, hydroxiurea, nocodazole and etoposide were used to arrest cells in the different stages, and it was observed that in sub-confluent cells, arrested in Go, the protein localized in the cytoplasm, and when the cell cycle was restored, p8 migrated back to the nucleus. Since previous results show that inhibitors of MAPK pathways alter the level of p8 expression, their effect on p8 localization was assayed, but none of the drugs had any effect on the protein?s localization. In the presence of a histone deacetylase inhibitor, Trichostatin A, sub-confluent cells showed cytoplasmic localization of p8.