title: p53-dependent control of transactivation of the Pen2 promoter by presenilins.
abstract: The senile plaques found in the brains of patients with Alzheimer's disease are mainly due to the accumulation of amyloid beta-peptides (A beta) that are liberated by gamma-secretase, a high molecular weight complex including presenilins, PEN-2, APH-1 and nicastrin. The depletion of each of these proteins disrupts the complex assembly into a functional protease. Here, we describe another level of regulation of this multimeric protease. The depletion of both presenilins drastically reduces Pen2 mRNA levels and its promoter transactivation. Furthermore, overexpression of presenilin-1 lowers Pen2 promoter transactivation, a phenotype abolished by a double mutation known to prevent presenilin-dependent gamma-secretase activity. PEN-2 expression is decreased by depletion of beta-amyloid precursor protein (APP) and increased by the APP intracellular domain (AICD). We show that AICD and APP complement for Pen2 mRNA levels in APP/APLP1-2 knockout fibroblasts. Interestingly, overexpression of presenilin-2 greatly increases Pen2 promoter transactivation. The opposite effect triggered by both presenilins was reminiscent of our previous study, which showed that these two proteins elicit antagonistic effects on p53. Therefore, we examined the contribution of p53 on Pen2 transcription. Pen2 promoter transactivation, and Pen2 mRNA and protein levels were drastically reduced in p53(-/-) fibroblasts. Furthermore, PEN-2 expression could be rescued by p53 complementation in p53- and APP-deficient cells. Interestingly, PEN-2 expression was also reduced in p53-deficient mouse brain. Overall, our study describes a p53-dependent regulation of PEN-2 expression by other members of the gamma-secretase complex, namely presenilins.
authors.affiliation: Institut de Pharmacologie Moléculaire et Cellulaire of Centre National de la Recherche Scientifique and Institut de NeuroMédecine Moléculaire, Equipe labellisée Fondation pour la Recherche Médicale, Valbonne, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Dunys
authors.forename: Jean
authors.initials: J
authors.lastname: Sevalle
authors.forename: Emilie
authors.initials: E
authors.lastname: Giaime
authors.forename: Raphaëlle
authors.initials: R
authors.lastname: Pardossi-Piquard
authors.forename: Michael P
authors.initials: MP
authors.lastname: Vitek
authors.forename: Paul
authors.initials: P
authors.lastname: Renbaum
authors.forename: Ephrat
authors.initials: E
authors.lastname: Levy-Lahad
authors.forename: Yun-wu
authors.initials: YW
authors.lastname: Zhang
authors.forename: Huaxi
authors.initials: H
authors.lastname: Xu
authors.forename: Frédéric
authors.initials: F
authors.lastname: Checler
authors.forename: Cristine Alves
authors.initials: CA
authors.lastname: da Costa
mesh_terms: D000544:Alzheimer Disease / Q000235:genetics / Q000378:metabolism; D053829:Amyloid Precursor Protein Secretases / Q000235:genetics* / Q000378:metabolism; D016564:Amyloid beta-Protein Precursor / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D053764:Presenilin-1 / Q000235:genetics / Q000378:metabolism*; D053766:Presenilin-2 / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D015533:Transcriptional Activation; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism*
chemical_list: D016564:Amyloid beta-Protein Precursor; D008565:Membrane Proteins; C469349:PSENEN protein, human; D053764:Presenilin-1; D053766:Presenilin-2; D016159:Tumor Suppressor Protein p53; D053829:Amyloid Precursor Protein Secretases