14-3-3 Protein family levels variations during differentiation of 3T3-L1 preadipocytes.

GOJANOVICH, A. D.; DIEGO M. BUSTOS; MARINA UHART

Rosario

Congreso; L Reunión Anual de la Sociedad Argentina de Investigaciones Bioquímicas y Biología Molecular (SAIB); 2014

SAIB

The 14-3-3 protein family comprises phospho-Serine/Threonine-binding proteins consisting of seven mammalian paralogs.  This protein family regulates several cellular processes including cellular differentiation. In adipogenesis, 14-3-3 regulates the subcellular localization of TAZ, a co-repressor of PPAR gamma dependent gene transcription. We studied the mRNA and protein levels of the 14-3-3 family before and after differentiation of NIH 3T3-L1 preadipocytes by using qPCR and Western Blot (WB) with specific primers and antibodies for each 14-3-3 member respectively.  The results revealed, after seven days of differentiation, a decrease in mRNA levels of 14-3-3 beta, epsilon and zeta and an increment of mRNA levels of 14-3-3 gamma, eta and tau, compared to undifferentiated cells. Protein levels of each paralog were either conserved or decreased after one week differentiation. A particularly pronounced decrease was observed in eta isoform protein. Therefore, an apparent discrepancy was observed between mRNA and protein levels of 14-3-3 eta, showing a specific degradation in response to differentiation signals in 3T3-L1 cells. Our findings indicate that the differential expression and/or postranslational regulation of 14-3-3 family members levels during 3T3-L1 adipogenesis may be a mechanism to indirectly modulate differentiation to the adipose linage.