IBR   13079
INSTITUTO DE BIOLOGIA MOLECULAR Y CELULAR DE ROSARIO
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Specific interaction between E2F1 and Sp1 regulates the expression of murine CTP:phosphocholine cytidylyltransferase alpha during the S-phase
Autor/es:
ELENA, CLAUDIA; BANCHIO, CLAUDIA
Lugar:
Mendoza
Reunión:
Otro; II Curso de Biología Celular - 21 al 26 de febrero del 2010, Mendoza, Argentina.; 2010
Institución organizadora:
Instituto Curie de Paris Francia-Training Unit IHEM PROBIOL (FCM- Universidad Nacional de Cuyo- CONICET)
Resumen:
The major route for phosphatidylcholine (PthCho) production is the CDP-choline pathway and the supply of CDP-choline is governed by the activity of CCT. Three isoforms are differentially expressed in tissues, but CCTa is the dominant isoform ubiquitously expressed. Stimulation of PtdCho synthesis is associated with cell cycle progression and is driven by transcriptional activation of CCTa. In this sense, we have identified an E2F binding site (-218/-212) in the proximal promoter region of this gene that was shown to activate CCTa transcription during the S phase of the cell cycle. Gel shift analysis using CCTa promoter derived probes led to the identification of several multiprotein complexes that revealed an association between E2F and Sp1 transcriptional factors. These findings were confirmed using TranSignal TF-TF Interaction Arrays. Further analysis using CCTα promoter luciferase reporter plasmids, and plasmids designed to overexpress or inhibit (siRNA) E2F and Sp1 expression were used to study CCTa promoter activity. These results implied that E2F interact with Sp1 and cooperatively activate CCTa transcription in the S phase. Finally, we demonstrated that CCTa is localized in the nucleus in cells transiting the S phase, whereas it is localized in the cytoplasm of G0-arrested cells, suggesting a specific role of nuclear CCTa.