c-FOS REGULATES AXON BRANCHING IN NEURONS

LUCIA RODRÍGUEZ-BERDINI; GABRIEL ORLANDO FERRERO; ANDRES CARDOZO-GIZZI; BEATRIZ LEONOR CAPUTTO

Mendoza

Congreso; Reunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2012

SAIB

It was previously shown in our laboratory that in addition to its nuclear activity, c-Fos associates to membranes of the endoplasmic reticulum (ER) and activates phospholipid synthesis. So, it might be associated with the molecular mechanisms that allow the higher rate of membrane genesis required for neuronal growth and differentiation. Primary cultures of hippocampal neurons were infected using a lentiviral vector that expresses a specific sequence (shRNA) against c-Fos to block its expression and no development of axonal processes was observed after 36 hours of culture. On the other hand, by immunofluorescence, we observed the presence of c-Fos co-localizing with ER markers in the neuronal soma and mainly forming structures at the branching sites of the neuronal processes. We observed co-immunoprecipitation of c-Fos with CCTβ2, an integral enzyme of the ER membranes that plays an important role during the formation of axon branches. Finally, FRET technique has given positive results for the interaction between these two proteins. These results support our hypothesis of the importance of c-Fos mediated activation of phospholipid synthesis during neuronal differentiation.