Specific subcellular targeting of PKC alpha and PKC epsilon in normal and tumoral lactotroph cells by PMA-mitogenic stimulus

PETITI JUAN PABLO; GUTIÉRREZ SILVINA; MUKDSI JORGE HUMBERTO; DE PAUL ANA LUCÍA; TORRES ALICIA INÉS

JOURNAL OF MOLECULAR HISTOLOGY

Springer

Año: 2009 vol. 40 p. 417 - 425

1567-2379

The variations of the intracellular localization of the individual protein kinase C (PKC) isoforms are related with their different biological functions. In this study, we have investigated the precise intracellular translocation of endogenous PKCa and PKCe in PMA-stimulated normal and tumoral lactotroph cells by using confocal and immunogold electron microscopy, which was correlated with the rate of cell proliferation of both pituitary cell phenotypes. The present results showed that the short phorbol ester incubation stimulated the proliferation of normal and tumoral lactotroph cells, as determined by the measurement of the BrdU-labelling index. The translocation of PKCa to plasma and nuclear membranes induced by PMA was more marked than that observed for PKCe in normal and tumoral lactotroph cells. Our results showed that PKCs translocation to the plasma and nuclear membranes varied from isozyme to isozyme emphasizing that PKCa  could be related with the mitogenic stimulus exerted by phorbol ester. These data support the notion that specific PKC isozymes may exert spatially defined effects by virtue of their directed translocation to distinct intracellular sites.