GENTI DE RAIMONDI SUSANA DEL VALLE
Congresos y reuniones científicas
Título:
Convergence of beta-catenin signalling and SF-1 transcription factor on StarD7 gene promoter
Autor/es:
RENA VIVIANA; FLORES-MARTÍN, JÉSICA; ANGELETTI SOFÍA; PANZETTA-DUTARI GRACIELA; GENTI DE RAIMONDI SUSANA
Reunión:
Congreso; IFPA Meeting 2010; 2010
Institución organizadora:
International Federation Placenta Associations
Resumen:
StarD7 belongs to the START-domain proteins that are involved in intracellular
transport and lipid metabolism. StarD7 was first identified
over-expressed in JEG-3 cells compared to normal and benign trophoblastic
samples. We previously reported that StarD7 expression was
independently regulated by b-catenin signaling and SF-1 factor at the
transcriptional level. Herein, a possible convergence between both activating
factors was investigated. To evaluate this hypothesis, JEG-3 cells
were co-transfected with the SF-1 or/and the constitutively active bcatenin
S33Y expression plasmids, together with the -938/+157 StarD7
promoter construct, which contains the SF-1 and TCF consensus binding
sites recognized by each protein. In addition, co-transfection assays were
performed using these protein expression plasmids and mutated promoter
versions in the SF-1 and TCF consensus sites (-938/+157mut SF1-1 and
-938/+157mut SF1-1/mut TCF).
The results of this work show that SF-1 and b-catenin synergically activate
StarD7 promoter. Moreover, these findings indicate that the TCF site
localized at -614/-608 bp plays an important role in this activation.
Furthermore, deletion of the 235-238 amino acids in the SF-1 transcription
factor, involved in the b-catenin physical interaction, abolished this transcriptional
activation; demonstrating that the interaction between the two
proteins is necessary for an efficient StarD7 transcriptional activation.
Finally, these data suggest that b-catenin could function as a bridge
between SF-1 and TCF forming a ternary complex, which would transcriptionally
activate StarD7 gene