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Berezovska O, Xia MQ, Page K, Wasco W, Tanzi RE, Hyman BT. Developmental regulation of presenilin mRNA expression parallels notch expression. J Neuropathol Exp Neurol 1997; 56:40-4. [PMID: 8990127 DOI: 10.1097/00005072-199701000-00004] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Mutations in the presenilin (PS) 1 and 2 genes are associated with autosomal dominant Alzheimer disease. PS1 shares striking homology with sel-12, a C. elegans gene implicated in the function of lin-12/Notch, a protein important in neurogenesis. We studied mRNA expression using RT-PCR and in situ hybridization techniques during neural development in mouse and rat. Strong expression of PSs and Notch1 was observed in embryos, especially in the ventricular zone, which decreased gradually as embryos developed. Very low levels of PSs and Notch were present in adulthood, their signals present primarily in the hippocampus and cerebellum. These observations show that, like Notch, PS1 and PS2 are strongly developmentally regulated, and support the plausibility of an interaction between PSs and Notch.
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77
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Page K, Hollister R, Tanzi RE, Hyman BT. In situ hybridization analysis of presenilin 1 mRNA in Alzheimer disease and in lesioned rat brain. Proc Natl Acad Sci U S A 1996; 93:14020-4. [PMID: 8943053 PMCID: PMC19487 DOI: 10.1073/pnas.93.24.14020] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/1996] [Accepted: 06/17/1996] [Indexed: 02/03/2023] Open
Abstract
Presenilin-1 (PS-1) gene mutations are responsible for the majority of the early onset familial forms of Alzheimer disease (AD). Neither PS-1's anatomic distribution in brain nor expression in AD have been reported. Using in situ hybridization in the rat forebrain, we show that PS-1 mRNA expression is primarily in cortical and hippocampal neurons, with less expression in subcortical structures, in a regional pattern similar to APP695. Excitotoxic lesions lead to loss of PS-1 signal. A neuronal pattern of expression of PS-1 mRNA was also observed in the human hippocampal formation. AD and control levels did not differ. PS-1 is expressed in brain areas vulnerable to AD changes more so than in areas spared in AD; however, PS-1 expression is not sufficient to mark vulnerable regions. Collectively, these data suggest that the neuropathogenic process consequent to PS-1 mutations begins in neuronal cell populations.
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78
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Guénette SY, Chen J, Jondro PD, Tanzi RE. Association of a novel human FE65-like protein with the cytoplasmic domain of the beta-amyloid precursor protein. Proc Natl Acad Sci U S A 1996; 93:10832-7. [PMID: 8855266 PMCID: PMC38241 DOI: 10.1073/pnas.93.20.10832] [Citation(s) in RCA: 134] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
We identified a novel human homologue of the rat FE65 gene, hFE65L, by screening the cytoplasmic domain of beta-amyloid precursor protein (beta PP) with the "interaction trap." The cytoplasmic domains of the beta PP homologues, APLP1 and APLP2 (amyloid precursor-like proteins), were also tested for interaction with hFE65L. APLP2, but not APLP1, was found to interact with hFE65L. We confirmed these interactions in vivo by successfully coimmunoprecipatating endogenous beta PP and APLP2 from mammalian cells overexpressing a hemagglutinin-tagged fusion of the C-terminal region of hFE65L. We report the existence of a human FE65 gene family and evidence supporting specific interactions between members of the beta PP and FE65 protein families. Sequence analysis of the FE65 human gene family reveals the presence of two phosphotyrosine interaction (PI) domains. Our data show that a single PI domain is sufficient for binding of hFE65L to the cytoplasmic domain of beta PP and APLP2. The PI domain of the protein, Shc, is known to interact with the NPXYp motif found in the cytoplasmic domain of a number of different growth factor receptors. Thus, it is likely that the PI domains present in the C-terminal moiety of the hFE65L protein bind the NPXY motif located in the cytoplasmic domain of beta PP and APLP2.
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79
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Cook DG, Sung JC, Golde TE, Felsenstein KM, Wojczyk BS, Tanzi RE, Trojanowski JQ, Lee VM, Doms RW. Expression and analysis of presenilin 1 in a human neuronal system: localization in cell bodies and dendrites. Proc Natl Acad Sci U S A 1996; 93:9223-8. [PMID: 8799182 PMCID: PMC38623 DOI: 10.1073/pnas.93.17.9223] [Citation(s) in RCA: 167] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Mutations in the recently identified presenilin 1 gene on chromosome 14 cause early onset familial Alzheimer disease (FAD). Herein we describe the expression and analysis of the protein coded by presenilin 1 (PS1) in NT2N neurons, a human neuronal model system. PS1 was expressed using recombinant Semliki Forest virions and detected by introduced antigenic tags or antisera to PS1-derived peptides. Immunoprecipitation revealed two major PS1 bands of approximately 43 and 50 kDa, neither of which were N-glycosylated or O-glycosylated. Immunoreactive PS1 was detected in cell bodies and dendrites of NT2N neurons but not in axons or on the cell surface. PS1 was also detected in BHK cells, where it was also intracellular and colocalized with calnexin, a marker for the rough endoplasmic reticulum. A mutant form of PS1 linked to FAD did not differ from the wild-type protein at the light microscopic level. The model system described here will enable studies of the function of PS1 in human neurons and the role of mutant PS1 in FAD.
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80
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Irizarry MC, Kim TW, McNamara M, Tanzi RE, George JM, Clayton DF, Hyman BT. Characterization of the precursor protein of the non-A beta component of senile plaques (NACP) in the human central nervous system. J Neuropathol Exp Neurol 1996; 55:889-95. [PMID: 8759778 DOI: 10.1097/00005072-199608000-00004] [Citation(s) in RCA: 154] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
A novel and highly conserved presynaptic protein has been independently described in rodents (synuclein/SYN-1), songbirds (synelfin), and humans (the precursor protein of the non-A beta component of senile plaques, NACP); a fragment of the latter has been detected in senile plaques in Alzheimer's disease (AD). We characterized the expression of NACP in human AD and non-AD brain. A subcellular fractionation study demonstrated that NACP was mainly localized to cytosolic fractions of human temporal cortex. NACP was also detectable in various membrane and vesicular fractions, suggesting that the protein was associated with membrane structures including synaptic vesicles. Pericellular immunostaining of the neuropil was observed in neocortical and limbic regions, supporting a synaptic localization. Senile plaques in AD brains were not immunoreactive, and confocal microscopy suggested a loss of NACP immunoreactivity in cored plaques. No difference was found in the amount of protein in AD and control frontal cortex, as measured by immunoblotting. PCR analysis showed that the full-length mRNA product was the major splice form in both AD and control human brains. Thus, despite the association of a hydrophobic fragment of NACP with senile plaques, our data suggest that the precursor itself is not a significant component of plaques and NACP synthesis is not substantially altered in AD. Nevertheless, the protein is an abundant component of synaptic regions prone to degeneration in AD, and may have a role in the expression or advancement of the disease.
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81
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Tanzi RE, Kovacs DM, Kim TW, Moir RD, Guenette SY, Wasco W. The gene defects responsible for familial Alzheimer's disease. Neurobiol Dis 1996; 3:159-68. [PMID: 8980016 DOI: 10.1006/nbdi.1996.0016] [Citation(s) in RCA: 201] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Four different genes have now been found to contain AD-associated mutations or polymorphisms. While the pathogenic mutations in the early-onset FAD genes, APP, PS1, and PS2 directly cause AD with nearly 100% penetrance, in a larger subset of AD cases with onset over 60 years (maximally for onset at 61-65 years), inheritance of the APOE4 allele confers increased risk for AD but is not sufficient to cause the disease. Together, these four genes appear to account for approximately 50% of FAD cases. We are actively screening the genome for additional FAD loci by genotyping markers in over 400 FAD nuclear pedigrees and affected sib-pairs (83% late-onset and 17% early-onset). We have recently discovered genetic linkage to a novel FAD locus on chromosome 12 as well as another putative locus on chromosome 3 (unpublished findings). Positional cloning strategies are currently under way to identify these potentially novel FAD genes. A common event which is associated with all of the known FAD genes is the excessive accumulation of the A beta peptide and deposition of beta-amyloid in the brain. Thus, a common pathogenic pathway for AD neuropathogenesis appears to center around the cellular trafficking, maturation, and processing of APP, and the subsequent generation, aggregation, and deposition of A beta (or more specifically, A beta 1-42). APP and presenilin gene mutations most likely act as either gain-of-function or dominant negative gene defects which may ultimately lead to the transport of APP into intracellular compartments that promote the enhanced production of A beta or A beta 1-42. AD patients who carry an APOE4 allele experience increased amyloid burden in their brains compared to APOE4-negative AD cases. Thus, the presence of APOE4 would also appear to lead to abnormal generation, aggregation, or clearance of A beta in the brain A beta, perhaps by working in concert with its neuronal receptor, LRP. While the exact mechanisms by which the known FAD gene changes lead to the onset of AD remain unclear, the available data indicate that novel therapies aimed at curbing the generation, aggregation, and deposition of A beta would appear to carry the greatest potential for the effective treatment of this formidable disease.
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82
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Kovacs DM, Fausett HJ, Page KJ, Kim TW, Moir RD, Merriam DE, Hollister RD, Hallmark OG, Mancini R, Felsenstein KM, Hyman BT, Tanzi RE, Wasco W. Alzheimer-associated presenilins 1 and 2: neuronal expression in brain and localization to intracellular membranes in mammalian cells. Nat Med 1996; 2:224-9. [PMID: 8574969 DOI: 10.1038/nm0296-224] [Citation(s) in RCA: 451] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Mutations in two recently identified genes appear to cause the majority of early-onset familial Alzheimer's disease (FAD). These two novel genes, presenilin 1 (PS1) and presenilin 2 (PS2) are members of an evolutionarily conserved gene family. The normal biological role(s) of the presenilins and the mechanism(s) by which the FAD-associated mutations exert their effect remain unknown. Employing in situ hybridization, we demonstrate that the expression patterns of PS1 and PS2 in the brain are extremely similar to each other and that messages for both are primarily detectable in neuronal populations. Immunochemical analyses indicate that PS1 and PS2 are similar in size and localized to similar intracellular compartments (endoplasmic reticulum and Golgi complex). FAD-associated mutations in PS1 and PS2 do not significantly modify either their migration patterns on SDS-polyacrylamide gel electrophoresis or their overall subcellular localization, although subtle differences in perinuclear staining were noted for mutant PS1.
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83
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84
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Kovacs DM, Wasco W, Witherby J, Felsenstein KM, Brunel F, Roeder RG, Tanzi RE. The upstream stimulatory factor functionally interacts with the Alzheimer amyloid beta-protein precursor gene. Hum Mol Genet 1995; 4:1527-33. [PMID: 8541835 DOI: 10.1093/hmg/4.9.1527] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The amyloid beta-protein precursor (APP) gives rise to the A beta peptide, which is deposited in the brains of patients with Alzheimer's disease and Down's syndrome. Overexpression of APP due to a third copy of the gene appears to correlate with very early onset of Alzheimer's disease neuropathology in the brains of Down's syndrome patients. Thus, the identification of the factors involved with transcriptional regulation of the APP gene could provide critical clues regarding the events leading to the formation of amyloid deposits. An overlapping AP-1/AP-4 site in the proximal promoter region (-39 to -49) of the human APP gene has previously been shown to increase transcription 4-fold. Here we identify the factor binding specifically to this element as the upstream stimulatory factor USF, unrelated to the c-fos/c-jun complex or the AP-4 factor. In vitro transcription and co-transfection studies show that USF activates transcription from the APP promoter and that the AP-1/AP-4 element participates in this activation. Modulation of APP expression via regulation of USF could potentially ameliorate the production of Alzheimer-augmented beta-amyloid.
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85
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Webster MT, Groome N, Francis PT, Pearce BR, Sherriff FE, Thinakaran G, Felsenstein KM, Wasco W, Tanzi RE, Bowen DM. A novel protein, amyloid precursor-like protein 2, is present in human brain, cerebrospinal fluid and conditioned media. Biochem J 1995; 310 ( Pt 1):95-9. [PMID: 7646477 PMCID: PMC1135859 DOI: 10.1042/bj3100095] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A monoclonal antibody, 3B11, was raised to a novel protein, amyloid precursor-like protein 2, which did not recognize amyloid precursor protein. Multiple bands were detected in human brain fractions and cell lysate by Western blotting, indicating the presence of isoforms, 3B11 immunoreactivity was also detected in cerebrospinal fluid and conditioned medium, indicating that the protein is secreted. Immunocytochemistry revealed 3B11 immunoreactivity in sections of human brain.
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86
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Kim TW, Wu K, Xu JL, McAuliffe G, Tanzi RE, Wasco W, Black IB. Selective localization of amyloid precursor-like protein 1 in the cerebral cortex postsynaptic density. BRAIN RESEARCH. MOLECULAR BRAIN RESEARCH 1995; 32:36-44. [PMID: 7494461 DOI: 10.1016/0169-328x(95)00328-p] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Senile plaques, a hallmark of Alzheimer's disease (AD), contain amyloid beta-peptide (A beta), which is generated from the larger amyloid beta protein precursor (APP). In addition to APP, several APP-related proteins have been recently identified in different organisms, including Drosophila amyloid precursor protein-like protein (APPL). Deficiency of APPL causes behavioral deficits in Drosophila, implicating a role in brain function. Moreover, mouse and human cDNA clones encoding amyloid precursor-like proteins (APLP1 and APLP2) have been identified and exhibit extensive sequence similarity to the APPL and APP genes. To define the potential role of APLP in the mammalian brain, we sought to directly localize APLP1 within the complex cortical synaptic structure. We focused on the postsynaptic density (PSD), which appears to be central to synaptic function. We now report that the 90 kDa APLP1, the first known APLP, is localized to the PSD from rat and human cerebral cortex. APLP1 increased during cortical synaptic development, suggesting a role in synaptogenesis or synaptic maturation. In contrast, APP was predominantly expressed in the synaptic membrane fraction, but was barely detectable in the PSD, including different subcellular distributions of APP and APLP1. Our observations raise the possibility that APLP1, a homologue of APPL, which appears to be necessary for normal behavior in Drosophila, participates in brain synaptic function in mammals.
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87
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Kounnas MZ, Moir RD, Rebeck GW, Bush AI, Argraves WS, Tanzi RE, Hyman BT, Strickland DK. LDL receptor-related protein, a multifunctional ApoE receptor, binds secreted beta-amyloid precursor protein and mediates its degradation. Cell 1995; 82:331-40. [PMID: 7543026 DOI: 10.1016/0092-8674(95)90320-8] [Citation(s) in RCA: 355] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The secreted form of beta-amyloid precursor protein (APP) containing the Kunitz proteinase inhibitor (KPI) domain, also called protease nexin II, is internalized and degraded by cells. We show that the low density lipoprotein (LDL) receptor-related protein (LRP) is responsible for the endocytosis of secreted APP. APPs770 degradation is inhibited by an LRP antagonist called the receptor-associated protein (RAP) and by LRP antibodies and is greatly diminished in fibroblasts genetically deficient in LRP. APPs695, which lacks the KPI domain, is a poor LRP ligand. Since LRP also binds apolipoprotein E (apoE)-enriched lipoproteins and inheritance of the epsilon 4 allele of the apoE gene is a risk factor for Alzheimer's disease (AD), these data link in a single metabolic pathway two molecules strongly implicated in the pathophysiology of AD.
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88
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Corder EH, Saunders AM, Strittmatter WJ, Schmechel DE, Gaskell PC, Rimmler JB, Locke PA, Conneally PM, Schmader KE, Tanzi RE. Apolipoprotein E, survival in Alzheimer's disease patients, and the competing risks of death and Alzheimer's disease. Neurology 1995; 45:1323-8. [PMID: 7617191 DOI: 10.1212/wnl.45.7.1323] [Citation(s) in RCA: 98] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The apolipoprotein E (APOE) epsilon 4 allele carries an increased risk of a patient developing Alzheimer's disease (AD) while the epsilon 2 allele carries a decreased risk. We compared survival from the onset of AD in subjects with different numbers of epsilon 4 alleles and evaluated changes in genotypic frequencies with age. Two subject groups were investigated: unrelated AD case and control subjects, and affected and unaffected members from 74 multiplex AD families. In both subject groups, survival from onset decreased with increasing onset age, was longer in women, and was unrelated to epsilon 4 gene dose. The epsilon 2/epsilon 3 genotype became more common with age (p = 0.004). The epsilon 4 allele decreased in frequency with age in all patient groups but, unexpectedly, remained unchanged in control subjects. We conclude that the progression of AD is not strongly related to epsilon 4 gene dose, that the higher prevalence of AD in women may involve the longer survival of affected women, and that AD and death are competing risks involving APOE that change over time.
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89
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90
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Sherrington R, Rogaev EI, Liang Y, Rogaeva EA, Levesque G, Ikeda M, Chi H, Lin C, Li G, Holman K, Tsuda T, Mar L, Foncin JF, Bruni AC, Montesi MP, Sorbi S, Rainero I, Pinessi L, Nee L, Chumakov I, Pollen D, Brookes A, Sanseau P, Polinsky RJ, Wasco W, Da Silva HA, Haines JL, Perkicak-Vance MA, Tanzi RE, Roses AD, Fraser PE, Rommens JM, St George-Hyslop PH. Cloning of a gene bearing missense mutations in early-onset familial Alzheimer's disease. Nature 1995; 375:754-60. [PMID: 7596406 DOI: 10.1038/375754a0] [Citation(s) in RCA: 2702] [Impact Index Per Article: 93.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Some cases of Alzheimer's disease are inherited as an autosomal dominant trait. Genetic linkage studies have mapped a locus (AD3) associated with susceptibility to a very aggressive form of Alzheimer's disease to chromosome 14q24.3. We have defined a minimal cosegregating region containing the AD3 gene, and isolated at least 19 different transcripts encoded within this region. One of these transcripts (S182) corresponds to a novel gene whose product is predicted to contain multiple transmembrane domains and resembles an integral membrane protein. Five different missense mutations have been found that cosegregate with early-onset familial Alzheimer's disease. Because these changes occurred in conserved domains of this gene, and are not present in normal controls, they are likely to be causative of AD3.
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91
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92
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Locke PA, Conneally PM, Tanzi RE, Gusella JF, Haines JL. Apolipoprotein E4 allele and Alzheimer disease: examination of allelic association and effect on age at onset in both early- and late-onset cases. Genet Epidemiol 1995; 12:83-92. [PMID: 7713402 DOI: 10.1002/gepi.1370120108] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
An increased frequency of the apolipoprotein E type 4 allele (APOE-4) has previously been associated with both late-onset sporadic and late-onset familial Alzheimer disease (AD) [Strittmatter et al. (1993) Proc Natl Acad Sci USA 90:1977-1981; Saunders et al. (1993a) Neurology 43:1467-1472]. To further investigate this association we genotyped affected individuals from 92 separate AD pedigrees including both early- and late-onset cases. An increased frequency of the APOE-4 allele was found only among the late-onset cases, both familial and sporadic, confirming the earlier reports. In addition, age at onset was significantly decreased in the APOE-4 homozygotes (in late onset families) compared to either APOE-4 heterozygotes or individuals not carrying an APOE-4 allele. We also observed a significantly decreased frequency of the APOE-2 allele in both the early- and late-onset familial cases. These results strengthen the argument for a direct role of APOE in susceptibility to AD.
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93
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Gregor P, Gaston SM, Yang X, O'Regan JP, Rosen DR, Tanzi RE, Patterson D, Haines JL, Horvitz HR, Uhl GR. Genetic and physical mapping of the GLUR5 glutamate receptor gene on human chromosome 21. Hum Genet 1994; 94:565-70. [PMID: 7959697 DOI: 10.1007/bf00211029] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Glutamate receptors (GluRs) mediate excitatory neurotransmission and may have important roles in central nervous system disorders. To characterize the human GLUR5 gene, which is located on human chromosome 21q22.1, we isolated cDNAs, genomic phage lambda clones, and yeast artificial chromosomes (YACs) and developed sequence tagged sites (STSs) and simple sequence length polymorphisms (SSLPs) for GLUR5. Genetic mapping with a tetranucleotide AGAT repeat named GLUR5/AGAT (six alleles observed, 70% heterozygosity) placed GLUR5 5 cM telomeric to APP (D21S210) and 3 cM centromeric to SOD1 (D21S223). The human GLUR5 gene is located near the familial amyotrophic lateral sclerosis (FALS) locus; linkage analysis of GLUR5 SSLPs in FALS pedigrees yielded negative lod scores, consistent with the recent association of the FALS locus with the SOD1 gene. Physical mapping of GLUR5 using a YAC contig suggested that the GLUR5 gene spans approximately 400-500kb, and is within 280kb of D21S213. The large size of the GLUR5 gene raises questions regarding its functional significance. Our GLUR5 YAC contig includes clones found in the Genethon chromosome 21 YAC contig, and reference to the larger contig indicates the orientation centromere--D21S213-GLUR5 5' end-GLUR5/AGAT--GLUR5 3' end--SOD1. The development of GLUR5/AGAT should permit rapid determination of the status of the GLUR5 gene in individuals with partial trisomy or monosomy of chromosome 21. Such studies may provide insights concerning the possible role of GLUR5 in Down syndrome.
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MESH Headings
- Base Sequence
- Chromosome Mapping
- Chromosomes, Artificial, Yeast
- Chromosomes, Human, Pair 21
- Cloning, Molecular
- Humans
- Lod Score
- Molecular Sequence Data
- Polymorphism, Genetic
- Receptors, Glutamate/genetics
- Recombination, Genetic
- Repetitive Sequences, Nucleic Acid/genetics
- Sequence Analysis, DNA
- Sequence Tagged Sites
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94
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Bush AI, Pettingell WH, de Paradis M, Tanzi RE, Wasco W. The amyloid beta-protein precursor and its mammalian homologues. Evidence for a zinc-modulated heparin-binding superfamily. J Biol Chem 1994; 269:26618-21. [PMID: 7929392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The Alzheimer beta-amyloid precursor protein (APP) contains an ectodomain zinc binding site that has been reported to modulate the heparin affinity and protease-inhibitory properties of the molecule. This motif, GVEFVCCP, is highly conserved in amyloid precursor-like proteins 1 and 2 (APLP1 and APLP2), as well as in the Drosophila and Caenorhabditis elegans APP-like proteins (APPL and APL-1). To determine whether the function of this domain is preserved in the human APP-like proteins, the effect of zinc in modulating the elution profile of these proteins upon heparin-Sepharose chromatography was studied. Both APLP1 and APLP2 bound heparin-Sepharose and had NaCl elution profiles similar to that of APP. As previously reported for APP, zinc increased the recovery of APLP1 and APLP2 upon heparin-Sepharose chromatography. APP, APLP1, and APLP2 all bind zinc-chelating Sepharose, indicating that the zinc binding motif may be functionally conserved in these proteins. Additionally, APP, APLP1, and APLP2 migrate at higher molecular sizes (approximately 40 kDa) on SDS-polyacrylamide gel electrophoresis than their predicted molecular sizes. We report data that compare the physicochemical properties of APP to its novel APLP homologues and indicate that these molecules behave as a family of zinc-modulated, heparin-binding proteins.
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95
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Muramatsu Y, Yamada T, Miura M, Sakai T, Suzuki Y, Serikawa T, Tanzi RE, Matsumoto K. Wilson's disease gene is homologous to hts causing abnormal copper transport in Long-Evans cinnamon rats. Gastroenterology 1994; 107:1189-92. [PMID: 7926469 DOI: 10.1016/0016-5085(94)90247-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND/AIMS The Long-Evans Cinnamon (LEC) mutant rat shows an excess copper accumulation in the liver and low serum ceruloplasmin activity. The disorder is controlled by a single autosomal recessive gene designated as hts. Wilson's disease is an autosomal recessive disorder of copper metabolism characterized by abnormal copper accumulation in the liver and low serum ceruloplasmin activity. The gene responsible for Wilson's disease has recently been isolated. The present study was designed to examine whether the LEC rat is an ideal animal model for Wilson's disease from a genetic point of view. METHODS For chromosomal mapping of hts, genetic linkage analysis using rat microsatellite marker loci was performed. Furthermore, cosegregation between hts and a rat counterpart of the Wilson's disease gene was analyzed. RESULTS hts was finely mapped to rat chromosome 16. Complete cosegregation between hts and a rat counterpart of the Wilson's disease gene was detected. CONCLUSIONS hts is likely to correspond to a rat homologue of the Wilson's disease gene. The present results allow us to propose that the LEC rat is an ideal animal model for Wilson's disease.
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96
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Bush AI, Pettingell WH, de Paradis M, Tanzi RE, Wasco W. The amyloid beta-protein precursor and its mammalian homologues. Evidence for a zinc-modulated heparin-binding superfamily. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)47062-7] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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97
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Bush AI, Pettingell WH, Multhaup G, d Paradis M, Vonsattel JP, Gusella JF, Beyreuther K, Masters CL, Tanzi RE. Rapid induction of Alzheimer A beta amyloid formation by zinc. Science 1994; 265:1464-7. [PMID: 8073293 DOI: 10.1126/science.8073293] [Citation(s) in RCA: 1152] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A beta 1-40, a major component of Alzheimer's disease cerebral amyloid, is present in the cerebrospinal fluid and remains relatively soluble at high concentrations (less than or equal to 3.7 mM). Thus, physiological factors which induce A beta amyloid formation could provide clues to the pathogenesis of the disease. It has been shown that human A beta specifically and saturably binds zinc. Here, concentrations of zinc above 300 nM rapidly destabilized human A beta 1-40 solutions, inducing tinctorial amyloid formation. However, rat A beta 1-40 binds zinc less avidly and is immune to these effects, perhaps explaining the scarcity with which these animals form cerebral A beta amyloid. These data suggest a role for cerebral zinc metabolism in the neuropathogenesis of Alzheimer's disease.
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98
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Cai X, Szabo P, Ali G, Tanzi RE, Blass JP. Pseudogene of dihydrolipoyl succinyltransferase (E2k) found by PCR amplification and direct sequencing of rodent-human cell hybrid DNAs. SOMATIC CELL AND MOLECULAR GENETICS 1994; 20:339-43. [PMID: 7974008 DOI: 10.1007/bf02254722] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Previous studies have indicated that the cDNA for the E2k component of the human alpha-ketoglutarate dehydrogenase complex (KGDHC) hybridized not only to a major locus on chromosome 14q24.3 in a region associated with familial Alzheimer's disease and with Joseph-Machado disease, but also to another locus on chromosome 1p31. We now report that PCR of genomic DNA and direct sequencing indicated that the chromosome 1 locus is an intronless pseudogene. PCR of genomic DNA amplified E2k fragments from mouse-human cell hybrids containing human chromosome 1 DNA but not from hybrids containing human chromosome 14 DNA. The resulting amplicons were of comparable sizes to those when the cDNA was used as template. The direct sequencing of these amplicons confirmed the lack of introns and indicated a frame shift, which led to the presence of four termination codons early in the coding region. PCR followed by direct sequencing of the amplicons appears to be a convenient method for identifying intronless pseudogenes.
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Bush AI, Pettingell WH, Paradis MD, Tanzi RE. Modulation of A beta adhesiveness and secretase site cleavage by zinc. J Biol Chem 1994; 269:12152-8. [PMID: 8163520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Abnormalities of zinc homeostasis occur in Alzheimer's disease (AD), a dementia characterized by the aggregation of A beta in the brain, and in Down syndrome, a condition characterized by premature AD. We studied the binding of Zn2+ to a synthetic peptide representing residues 1-40 (A beta 1-40), as well as other domains of A beta. Two classes of Zn2+ binding were identified by 65Zn2+ labeling: highly specific pH-dependent high affinity (K(a) = 107 nM) binding, and lower affinity (K(a) = 5.2 microM) binding. Gel filtration chromatography identified monomeric, dimeric, and polymeric A beta species. Zinc induced a marked loss of A beta solubility upon chromatographic analysis. This was attributed to precipitation onto the column glass, which contains aluminosilicate, and was confirmed by the observation of zinc-accelerated precipitation of A beta by kaolin, a hydrated aluminum silicate suspension. Zinc binding also increased A beta resistance to tryptic cleavage at the secretase site, indicating that a small (<3 microM) increase in brain Zn2+ concentration could significantly alter A beta metabolism. We propose that elevated brain interstitial zinc levels may increase A beta adhesiveness and interfere with A beta catabolism. Consequently, abnormalities of regional zinc concentrations in the brains of patients with AD or Down syndrome may contribute to A beta amyloidosis in these disorders.
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Ali G, Wasco W, Cai X, Szabo P, Sheu KF, Cooper AJ, Gaston SM, Gusella JF, Tanzi RE, Blass JP. Isolation, characterization, and mapping of gene encoding dihydrolipoyl succinyltransferase (E2k) of human alpha-ketoglutarate dehydrogenase complex. SOMATIC CELL AND MOLECULAR GENETICS 1994; 20:99-105. [PMID: 8009371 DOI: 10.1007/bf02290679] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We have isolated and sequenced cDNAs representing the full-length (2987-bp) gene for dihydrolipoyl succinyltransferase (E2k component) of the human alpha-ketoglutarate dehydrogenase complex (KGDHC) from a human fetal brain cDNA library. The E2k cDNA was mapped to human chromosome 14 using a somatic cell hybrid panel, and more precisely to band 14q24.3 by in situ hybridization. This cDNA also cross-hybridized to an apparent E2k pseudogene on chromosome 1p31. Northern analysis revealed the E2k gene to be ubiquitously expressed in peripheral tissues and brain. Interestingly, chromosome 14q24.3 has recently been reported to contain gene defects for an early-onset form of familial Alzheimer's disease and for Machado-Joseph disease. Future studies will be necessary to determine whether the E2k gene plays a role in either of these two disorders.
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