title: Transcriptional regulation of the presenilin-1 gene controls gamma-secretase activity.
abstract: Inhibition of basal JNK activity by JNK inhibitor SP600125 or JNK1siRNA repressed presenilin-1 (PS1) expression in SK-N-SH cells by augmenting the level of p53, a repressor of the PS1 gene (1). We now showed that repression of PS1 transcription by JNK inhibitor SP600125 inhibited gamma-secretase mediated processing of amyloid precursor protein (APP) resulting in the accumulation of C99 fragment and the reduction of secreted Abeta40 level without altering the expression of nicastrin (NCT). Co-treatment of cells with SP600125 and p53 inhibitor, pifithrin-alpha, partially nullified the suppressive effects of SP610025 on PS1 expression and secreted Abeta40 level. Suppression of JNK1 by JNK1siRNA also decreased Abeta40 level. Furthermore, overexpression of the repressors p53, ZNF237 and CHD3 of the PS1 gene also suppressed the processing of APP through repression of PS1 transcription by deacetylation of histone at the PS1 promoter. Transcriptional activator Ets2 increased PS1 protein and secreted Abeta40 levels without affecting the expression of NCT by activating PS1 transcription via hyper-acetylation of histone at the PS1 promoter. Therefore, regulation of PS1 transcription modulates gamma-secretase activity.
authors.affiliation: Department of Pharmacology and Neuroscience, University of North Texas Health Science Center at Fort Worth, 3500 Camp Bowie Boulevard, Fort Worth, Texas 76107, USA.
authors.forename: Sebum
authors.initials: S
authors.lastname: Lee
authors.forename: Hriday K
authors.initials: HK
authors.lastname: Das
mesh_terms: D053829:Amyloid Precursor Protein Secretases / Q000378:metabolism*; D016229:Amyloid beta-Peptides / Q000378:metabolism; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D000704:Analysis of Variance; D000873:Anthracenes / Q000494:pharmacology; D052160:Benzothiazoles / Q000494:pharmacology; D015153:Blotting, Western; D045744:Cell Line, Tumor; D047369:Chromatin Immunoprecipitation; D017931:DNA Primers / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D005786:Gene Expression Regulation / Q000187:drug effects* / Q000502:physiology; D005822:Genetic Vectors / Q000235:genetics; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors; D010446:Peptide Fragments / Q000378:metabolism; D053764:Presenilin-1 / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014050:Toluene / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D016229:Amyloid beta-Peptides; D016564:Amyloid beta-Protein Precursor; D000873:Anthracenes; D052160:Benzothiazoles; D017931:DNA Primers; D010446:Peptide Fragments; D053764:Presenilin-1; C078592:amyloid beta-protein (1-40); C432165:pyrazolanthrone; D014050:Toluene; C121565:pifithrin; D048031:JNK Mitogen-Activated Protein Kinases; D053829:Amyloid Precursor Protein Secretases