PuF, an antimetastatic and developmental signaling protein, interacts with the Alzheimer’s amyloid-β precursor protein via a tissue-specific proximal regulatory element (PRE)

BMC Genomics

Research Article

Bryan Maloney¹  Yuan-Wen Ge¹  Debomoy K Lahiri²  Jack T Rogers³ 

[1] Laboratory of Molecular Neurogenetics, Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, 791 Union Drive, 46202, Indianapolis, IN, USA;Laboratory of Molecular Neurogenetics, Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, 791 Union Drive, 46202, Indianapolis, IN, USA;Department of Medical and Molecular Genetics, Indiana University School of Medicine, 46202, Indianapolis, IN, USA;Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, 46202, Indianapolis, IN, USA;Neurochemistry lab, Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, 02129, Charleston, MA, USA;

关键词: Amyloid precursor protein;    Alzheimer’s disease;    Cancer;    Gene regulation;    Gene transcription;    Iron;    Latency;    nm23 nucleoside diphosphate kinase;    Oncogenesis;    PuF;    SP1;    Specificity protein 1;    Transcription factor;   

DOI  :  10.1186/1471-2164-14-68

 received in 2012-08-10, accepted in 2012-11-10,  发布年份 2013

来源: Springer

【 摘 要 】

BackgroundAlzheimer’s disease (AD) is intimately tied to amyloid-β (Aβ) peptide. Extraneuronal brain plaques consisting primarily of Aβ aggregates are a hallmark of AD. Intraneuronal Aβ subunits are strongly implicated in disease progression. Protein sequence mutations of the Aβ precursor protein (APP) account for a small proportion of AD cases, suggesting that regulation of the associated gene (APP) may play a more important role in AD etiology. The APP promoter possesses a novel 30 nucleotide sequence, or “proximal regulatory element” (PRE), at −76/−47, from the +1 transcription start site that confers cell type specificity. This PRE contains sequences that make it vulnerable to epigenetic modification and may present a viable target for drug studies. We examined PRE-nuclear protein interaction by gel electrophoretic mobility shift assay (EMSA) and PRE mutant EMSA. This was followed by functional studies of PRE mutant/reporter gene fusion clones.ResultsEMSA probed with the PRE showed DNA-protein interaction in multiple nuclear extracts and in human brain tissue nuclear extract in a tissue-type specific manner. We identified transcription factors that are likely to bind the PRE, using competition gel shift and gel supershift: Activator protein 2 (AP2), nm23 nucleoside diphosphate kinase/metastatic inhibitory protein (PuF), and specificity protein 1 (SP1). These sites crossed a known single nucleotide polymorphism (SNP). EMSA with PRE mutants and promoter/reporter clone transfection analysis further implicated PuF in cells and extracts. Functional assays of mutant/reporter clone transfections were evaluated by ELISA of reporter protein levels. EMSA and ELISA results correlated by meta-analysis.ConclusionsWe propose that PuF may regulate the APP gene promoter and that AD risk may be increased by interference with PuF regulation at the PRE. PuF is targeted by calcium/calmodulin-dependent protein kinase II inhibitor 1, which also interacts with the integrins. These proteins are connected to vital cellular and neurological functions. In addition, the transcription factor PuF is a known inhibitor of metastasis and regulates cell growth during development. Given that APP is a known cell adhesion protein and ferroxidase, this suggests biochemical links among cell signaling, the cell cycle, iron metabolism in cancer, and AD in the context of overall aging.

【 授权许可】

CC BY   
© Lahiri et al.; licensee BioMed Central Ltd. 2013