title: Reduced RAN expression and disrupted transport between cytoplasm and nucleus; a key event in Alzheimer's disease pathophysiology.
abstract: Transcription of DNA is essential for cell maintenance and survival; inappropriate localization of proteins that are involved in transcription would be catastrophic. In Alzheimer's disease brains, and in vitro studies, we have found qualitative and quantitative deficits in transport into the nucleus of DNA methyltransferase 1 (DNMT1) and RNA polymerase II (RNA pol II), accompanied by their abnormal sequestration in the cytoplasm. RAN (RAs-related Nuclear protein) knockdown, by siRNA and oligomeric Aβ42 treatment in neurons, replicate human data which indicate that transport disruption in AD may be mechanistically linked to reduced expression of RAN, a pivotal molecule in nucleocytoplasmic transport. In vitro studies also indicate a significant role for oligomeric Aβ42 in the observed phenomena. We propose a model in which reduced transcription regulators in the nucleus and their increased presence in the cytoplasm may lead to many of the cellular manifestations of Alzheimer's disease.
authors: L. J. Roberts Alzheimer's Disease Center, Banner Sun Health Research Institute, Sun City, Arizona, United States of America.
authors: Diego
authors: D
authors: Mastroeni
authors: Leonidas
authors: L
authors: Chouliaras
authors: Andrew
authors: A
authors: Grover
authors: Winnie S
authors: WS
authors: Liang
authors: Kevin
authors: K
authors: Hauns
authors: Joseph
authors: J
authors: Rogers
authors: Paul D
authors: PD
authors: Coleman
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000235:genetics* / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D016229:Amyloid beta-Peptides / Q000494:pharmacology; D001344:Autopsy; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D002531:Cerebellum / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000235:genetics / Q000378:metabolism; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D008032:Limbic System / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology; D012319:RNA Polymerase II / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction / Q000187:drug effects; D014158:Transcription, Genetic / Q000187:drug effects; D020931:ran GTP-Binding Protein / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C120587:RAN protein, human; D034741:RNA, Small Interfering; C075222:amyloid beta-protein (1-42); D000076123:DNA (Cytosine-5-)-Methyltransferase 1; D004248:DNA (Cytosine-5-)-Methyltransferases; C000619380:DNMT1 protein, human; D012319:RNA Polymerase II; D020931:ran GTP-Binding Protein