DOCSLIB.ORG

Functional Studies of Alzheimer's Disease Tau Protein

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Functional Studies of Alzheimer's Disease Tau Protein The Journal of Neuroscience, February 1993, 13(2): 508415 Functional Studies of Alzheimer’s Disease Tau Protein Qun Lu and John G. Wood Department of Anatomy and Cell Biology, Emory University School of Medicine, Atlanta, Georgia 30322 In vitroassays were used to monitor and compare the kinetic concentration at which pure tubulin assembles(Weingarten et behavior of bovine tubulin polymerization enhanced by tau al., 1975; Cleveland et al., 1977). In cultured fibroblasts, which proteins isolated from Alrheimer’s disease (AD) and nonde- do not contain endogenoustau, microinjected tau can incor- mented (ND) age-matched control brains. Tau from AD cases porate into microtubules and stabilize them against depoly- induced slower polymerization and a steady state turbidity merization conditions (Drubin and Kirschner, 1986; Lu and value approximately 50% of that stimulated by tau from con- Wood, 1991b). trol cases. Tau from the most severe AD case was least In brain, tau is largely localized in axons (Binder et al., 1985; effective at promoting polymerization. Dark-field light mi- Brion et al., 1988). However, in AD brain tau becomes an croscopy of the control samples revealed abundant micro- integral part of paired helical filaments (PHFs) in neurofibrillary tubule formation and many microtubule bundles. Microtubule tangles of neuronal cell bodies as well as dystrophic neurites assembly was observed in AD samples as well, but bundling associatedwith neuritic plaques (Brion et al., 1985; Grundke- was not obvious. These results were confirmed by negative- Iqbal et al., 1986, 1988; Kosik et al., 1986; Wood et al., 1986). stain electron microscopy. Morphological analysis showed This dislocation is accompanied by abnormal phosphorylation that AD tau-induced microtubules were longer than control (Grundke-Iqbal et al., 1986; Wood et al., 1986; Iqbal et al., microtubules. Furthermore, our initial results suggest that 1989; Brion et al., 199la; Lee et al., 199 1). Recently, it was the reduction of AD tau activity is correlated with neurofi- found that A68, a putative AD-specific protein (Wolozin et al., brillary pathology in AD brains. Earlier reports indicated that 1986), is an abnormally phosphorylated tau and is the only AD tau is modified by phosphorylation (Grundke-lqbal et al., component of a classof PHFs (Lee et al., 1991). The tubulins, 1988; Wood et al., 1988; lqbal et al., 1989; Brion et al., 1991 a,b; the main building block of microtubules from AD brain, are Lee et al., 1991). Our results support the hypothesis that tau functionally competent to reassembleand form microtubules modification compromises its function by altering its ability in vitro, but microtubule assemblyfrom AD brain homogenates to nucleate and bundle microtubules. is not observed (Iqbal et al., 1986). Thus, modification of tau [Key words: Alzheimer’s disease, tau protein, microtubule may be responsiblefor the defective microtubule assembly,as assembly, functional alteration, kinetic assay, light and elec- phosphorylated bovine tau was found to be less efficient in tron microscopy] promoting tubulin polymerization than dephosphorylated tau (Lindwall and Cole, 1984). Although it is reasonable to hy- pothesize that the alteration of tau distribution and chemistry Microtubules are the fundamental organelle for fast axonal contributes to the disruption of neuronal microtubule integrity transport, which is essentialfor the renewal of axons and mem- and the formation of AD pathology, it has not been established branes in the nerve terminal. Defective microtubule assembly whether AD tau, before it transforms into PHFs, is still func- and stabilization in neurons, therefore, could lead to impaired tional. In this study, we used in vitro assaysincluding kinetic axonal transport and abnormal synaptic transmission.The sta- analysisand subsequentdark-field light microscopy and electron bility of microtubules in neurons can be achieved in a number microscopy to addressthe questionswhether AD tau in soluble of ways, including tubulin posttranslational modification and form is functionally competent to promote microtubule for- the regulation of microtubule-associated proteins (MAPS) of mation and whether the microtubules thus formed expressdis- either the high-molecular-weight MAPS or the low-molecular- tinct behavior and morphology when compared with that stim- weight tau proteins (for review, seeMatus, 1988; Mitchison and ulated by ND tau. The results show that AD tau can stimulate Kirschner, 1988). microtubule assembly but with slower kinetics and different Tau proteins are a heat-stablefamily of developmentally reg- microtubule morphology, which supports the hypothesis that ulated phosphoproteinsthat are generatedby alternative splic- abnormal tau is involved in modification of the neuronal mi- ing of a singlegene (Drubin et al., 1984; Lee et al., 1988; Himm- crotubule system and AD pathogenesis. let-, 1989;Kosik et al., 1989). Zn vitro, tau stimulatesthe assembly of microtubules at tubulin concentrations well below the critical Materials and Methods Protein puriJicution. Bovine tubulin was isolated through temperature- dependent microtubule polymerization-depolymerization cycles and Received May 4, 1992; revised July 2 1, 199 1; accepted July 23, 1992. further purified by DEAE-Sephacelion exchangecolumn chromatog- We thank Dr. L. Binder for providing mAb Tau- 1, and Ms. J. Soria and Mr. raphy (Detrich. 1986). Tau was isolated using a modified method (Pol- R. Gopal for technical assistance. This work was supported by NIH Grants AG lock and Wood, 1988) of perchloric acid extraction of heat-stable frac- 06383, AG 11123, and NS 27847. tions (HSF) by Baudier et al. (1987). Fresh half AD or ND brains with Correspondence should be. addressed to J. G. Wood at the above address. averagepostmortem times of 7 hr were homogenizedin cold 20 mM Copyright 0 1993 Society for Neuroscience 0270-6474/93/130508-08$05.00/O 2-[N-morpholinolethanesulfonic acid (MES) buffer, pH 6.85 with 2 mM The Journal of Neuroscience, February 1993, 73(2) 509 ethylene glycol bis(@aminoethyl) ether-N,N,N’,N’-tetra-acetic acid (EGTA), 1 mM MgSO,, 0.75 M NaCl, and 1 mM fi-mercaptoethanol. A B Protease inhibitors leupeptin (10 pg/ml), pepstatin A (10 pg/ml), apro- tinin (125 KIU/mk KIU = Kallikrein inhibitorv unit), and 2 mM phen- vlmethylsulfonyl fluoride (PMSF) were added fresh to the buffer before 4 homogenization. The 75,000 x g supematant of brain homogenates was boiled at 95°C for 5 min in the same buffer with 0.75 M NaCl and 2 mM m-dithiothreitol (DTT) to generate HSF. Proteins other than tau 4 were precipitated by perchloric acid treatment and removed by cen- trifugation. Tau was also separated from high-molecular-weight micro- tubule-associated protein MAP-2 by molecular sieve chromatography 4 of the HSF on a Bio-Gel A 1.5 M column. Tau protein used for kinetic experiments was concentrated using an ultrafiltration unit (Amicon Corp., Danvers, MA) to 3-5 mg/ml and centrifuged at 45,000 x g for 20 min to remove aggregates before experiments. Proteinconcentrations were 4 determined using a Bio-Rad protein assay based on the Bradford method (1976). Western blot analysis was performed as described previously (Wood et al., 1986). Quantitative analysis of the bands and the ratio of 4 tau to tau fragments was performed using a Bio-Rad 620 video densi- tometer. Putholonv. Hippocampal slices from AD and ND brains were fixed in fresh PEP (p&formaldehyde, lysine, sodium periodate, and NaCl) mixture of McLean and Nakane ( 1974). Vibratome sections, 50 Brn, of hippocampus were stained using‘a modified Sevier-Munger silver im- pregnation method (Sevier and Munger, 1965). The occurrences of tan- gles and plaques were counted primarily in CA1 and CA4 subdivision of hippocampi at 200 x under the Zeiss Axiovert 35 light microscope. Figure 1. Western Blots of the proteins isolated for in vitro assays. A, The densities of tangles and plaques were determined by averaging the Bovine tubulin immunostained with monoclonal anti-a tubulin DM 1 A, data from total area of 2.1-10.8 mm2 with statistical analysis performed B, isolated human tau immunoblotted with mAb Tau- 1. Gel lanes were using CRICKET GRAPH software on the Apple Macintosh IIci computer. loaded with 4.2 pg total protein. Molecular weight standards are indi- Kineticanalysis. DEAE-Sephacel tubulin was mixed with AD or ND cated on the right (arrowheads);from top to bottom: 205 kDa, 116 kDa, tau at 4°C and polymerization was initiated in 0.1 M piperazine-N,N’- 66 kDa, 45 kDa, and 36 kDa. bis[2-ethanesulfonic acid] (PIPES) with 2 mM EGTA and 1 mM MgSO,, pH 6.72, by adding 1 mM guanosine 5’-triphosphate (GTP) and raising the temperature to 37°C. The kinetic behavior was monitored by re- Western blots of typical samplesof bovine tubulin and human cordine turbiditv changes at 350 nm o.d. using a Beckman DU-64 UV tau usedfor kinetic analysis. The bovine tubulin was devoid of spectrgphotomeier with a Kinetics Soft-Pa& module and temperature controller. microtubule-associatedproteins asjudged by Coomassieblue- Light and electronmicroscopy. After the kinetic measurements were stained gels (data not shown). AD and ND tau were isolated completed, aliquots were taken from cuvettes for dark-field light mi- based on the heat-stable and perchloric acid-soluble properties croscopic examination. In addition, 5 ~1 aliquots were dropped onto of tau proteins. Human tau proteins isolated by our method Formvar-coated grids and negatively stained with 2% uranyl acetate for electron microscopy. Some samples were fixed in 0.2% glutaraldehyde contained the major isoforms at 55-70 kDa MW with some prior to electron microscopic (EM) examination. For thin-section elec- degradation products. These bands were reactive with Tau-l tron microscopy, aliquots were centrifuged at 45,000 x g for 30 min monoclonal anti-tau (a gift generouslyprovided by Dr. L. Binder at 32°C to nellet microtubules. These samples were then fixed in 0.2% at the University of Alabama, Birmingham) and polyclonal anti- glutaraldehyde, postfixed in 1% OsO,, and embedded for thin sectioning.
Load more

Recommended publications
  • Elucidating Crosstalk Mechanisms Between Phosphorylation and O
    Elucidating crosstalk mechanisms between PNAS PLUS phosphorylation and O-GlcNAcylation Aneika C. Leneya,b,c,d, Dris El Atmiouie, Wei Wua,b,c,d, Huib Ovaae, and Albert J. R. Hecka,b,c,d,1 aBiomolecular Mass Spectrometry and Proteomics, Utrecht University, 3584 CH Utrecht, The Netherlands; bBijvoet Center for Biomolecular Research, Utrecht University, 3584 CH Utrecht, The Netherlands; cUtrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CH Utrecht, The Netherlands; dNetherlands Proteomics Centre, Utrecht University, 3584 CH Utrecht, The Netherlands; and eChemical Immunology, Leiden University Medical Centre, 2333 ZA Leiden, The Netherlands Edited by Tony Hunter, The Salk Institute for Biological Studies, La Jolla, CA, and approved July 21, 2017 (received for review December 14, 2016) Proteins can be modified by multiple posttranslational modifications from studies in which cellular stimuli were shown to increase both (PTMs), creating a PTM code that controls the function of proteins in O-GlcNAcylation and phosphorylation levels simultaneously (6, 7). space and time. Unraveling this complex PTM code is one of the great Although, many studies have demonstrated that crosstalk occurs, challenges in molecular biology. Here, using mass spectrometry-based studies that identify and colocalize both the phosphorylation and assays, we focus on the most common PTMs—phosphorylation and O-GlcNAcylation sites simultaneously on the same protein/peptide O-GlcNAcylation—and investigate how they affect each other. We are sporadic. Thus, doubt still exists as to whether on a specific demonstrate two generic crosstalk mechanisms. First, we define a protein molecule O-GlcNAcylation directly affects phosphorylation frequently occurring, very specific and stringent phosphorylation/ or vice versa.
    [Show full text]
  • NIH Public Access Author Manuscript J Neuropathol Exp Neurol
    NIH Public Access Author Manuscript J Neuropathol Exp Neurol. Author manuscript; available in PMC 2010 September 24. NIH-PA Author ManuscriptPublished NIH-PA Author Manuscript in final edited NIH-PA Author Manuscript form as: J Neuropathol Exp Neurol. 2009 July ; 68(7): 709±735. doi:10.1097/NEN.0b013e3181a9d503. Chronic Traumatic Encephalopathy in Athletes: Progressive Tauopathy following Repetitive Head Injury Ann C. McKee, MD1,2,3,4, Robert C. Cantu, MD3,5,6,7, Christopher J. Nowinski, AB3,5, E. Tessa Hedley-Whyte, MD8, Brandon E. Gavett, PhD1, Andrew E. Budson, MD1,4, Veronica E. Santini, MD1, Hyo-Soon Lee, MD1, Caroline A. Kubilus1,3, and Robert A. Stern, PhD1,3 1 Department of Neurology, Boston University School of Medicine, Boston, Massachusetts 2 Department of Pathology, Boston University School of Medicine, Boston, Massachusetts 3 Center for the Study of Traumatic Encephalopathy, Boston University School of Medicine, Boston, Massachusetts 4 Geriatric Research Education Clinical Center, Bedford Veterans Administration Medical Center, Bedford, Massachusetts 5 Sports Legacy Institute, Waltham, MA 6 Department of Neurosurgery, Boston University School of Medicine, Boston, Massachusetts 7 Department of Neurosurgery, Emerson Hospital, Concord, MA 8 CS Kubik Laboratory for Neuropathology, Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts Abstract Since the 1920s, it has been known that the repetitive brain trauma associated with boxing may produce a progressive neurological deterioration, originally termed “dementia pugilistica” and more recently, chronic traumatic encephalopathy (CTE). We review the 47 cases of neuropathologically verified CTE recorded in the literature and document the detailed findings of CTE in 3 professional athletes: one football player and 2 boxers.
    [Show full text]
  • Microtubule-Associated Protein Tau (Molecular Pathology/Neurodegenerative Disease/Neurofibriliary Tangles) M
    Proc. Nati. Acad. Sci. USA Vol. 85, pp. 4051-4055, June 1988 Medical Sciences Cloning and sequencing of the cDNA encoding a core protein of the paired helical filament of Alzheimer disease: Identification as the microtubule-associated protein tau (molecular pathology/neurodegenerative disease/neurofibriliary tangles) M. GOEDERT*, C. M. WISCHIK*t, R. A. CROWTHER*, J. E. WALKER*, AND A. KLUG* *Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, United Kingdom; and tDepartment of Psychiatry, University of Cambridge Clinical School, Hills Road, Cambridge CB2 2QQ, United Kingdom Contributed by A. Klug, March 1, 1988 ABSTRACT Screening of cDNA libraries prepared from (21). This task is made all the more difficult because there is the frontal cortex ofan zheimer disease patient and from fetal no functional or physiological assay for the protein(s) of the human brain has led to isolation of the cDNA for a core protein PHF. The only identification so far possible is the morphol- of the paired helical fiament of Alzheimer disease. The partial ogy of the PHFs at the electron microscope level, and here amino acid sequence of this core protein was used to design we would accept only experiments on isolated individual synthetic oligonucleotide probes. The cDNA encodes a protein of filaments, not on neurofibrillary tangles (in which other 352 amino acids that contains a characteristic amino acid repeat material might be occluded). One thus needs a label or marker in its carboxyl-terminal half. This protein is highly homologous for the PHF itself, which can at the same time be used to to the sequence ofthe mouse microtubule-assoiated protein tau follow the steps of the biochemical purification.
    [Show full text]
  • Neurofilaments: Neurobiological Foundations for Biomarker Applications
    Neurofilaments: neurobiological foundations for biomarker applications Arie R. Gafson1, Nicolas R. Barthelmy2*, Pascale Bomont3*, Roxana O. Carare4*, Heather D. Durham5*, Jean-Pierre Julien6,7*, Jens Kuhle8*, David Leppert8*, Ralph A. Nixon9,10,11,12*, Roy Weller4*, Henrik Zetterberg13,14,15,16*, Paul M. Matthews1,17 1 Department of Brain Sciences, Imperial College, London, UK 2 Department of Neurology, Washington University School of Medicine, St Louis, MO, USA 3 a ATIP-Avenir team, INM, INSERM , Montpellier university , Montpellier , France. 4 Clinical Neurosciences, Faculty of Medicine, University of Southampton, Southampton General Hospital, Southampton, United Kingdom 5 Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Québec, Canada 6 Department of Psychiatry and Neuroscience, Laval University, Quebec, Canada. 7 CERVO Brain Research Center, 2601 Chemin de la Canardière, Québec, QC, G1J 2G3, Canada 8 Neurologic Clinic and Policlinic, Departments of Medicine, Biomedicine and Clinical Research, University Hospital Basel, University of Basel, Basel, Switzerland. 9 Center for Dementia Research, Nathan Kline Institute, Orangeburg, NY, 10962, USA. 10Departments of Psychiatry, New York University School of Medicine, New York, NY, 10016, 11 Neuroscience Institute, New York University School of Medicine, New York, NY, 10016, USA. 12Department of Cell Biology, New York University School of Medicine, New York, NY, 10016, USA 13 University College London Queen Square Institute of Neurology, London, UK 14 UK Dementia Research Institute at University College London 15 Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden 16 Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden 17 UK Dementia Research Institute at Imperial College, London * Co-authors ordered alphabetically Address for correspondence: Prof.
    [Show full text]
  • Expression of Separate Isoforms of Human Tau Protein: Correlation with the Tau Pattern in Brain and Effects on Tubulin Polymerization
    The EMBO Journal vol.9 no.13 pp.4225-4230, 1990 Expression of separate isoforms of human tau protein: correlation with the tau pattern in brain and effects on tubulin polymerization Michel Goedert and Ross Jakes half of the molecule. Experiments using tau fragments synthesized in vitro and synthetic peptides have shown that Medical Research Council Laboratory of Molecular Biology, Hills the repeats constitute microtubule binding units (Aizawa et Road, Cambridge CB2 2QH, UK al., 1989; Ennulat et al., 1989; Himmler et al., 1989; Lee Communicated by R.A.Crowther et al., 1989). Additional isoforms exist which contain 29 or 58 amino acid insertions in the amino-terminal region in conjunction with three or four repeats, giving rise in humans We have expressed six previously cloned isoforms of to a total of six different isoforms identified from full-length human microtubule-associated tau protein in Escherichia cDNA clones (Goedert et al., 1989b). The shortest human coli and purified them to homogeneity in a biologically form is 352 amino acids in length and contains three repeats, active form. They range from 352 to 441 amino acids in whereas the largest form is 441 amino acids in length and length and differ from each other by the presence of three contains four repeats and the 58 amino acid insertion. By or four tandem repeats in the carboxy-terminal half and RNase protection assay on human brain, mRNAs encoding by the presence or absence of 29 or 58 amino acid inserts three-repeat containing isoforms are found both in fetal and in the amino-terminus.
    [Show full text]
  • Aluminum Neurotoxicity — Potential Role in the Pathogenesis of Neurofibrillary Tangle Formation Daniel P
    LE JOURNAL CANADIEN DES SCIENCES NEUROLOGIQUES Aluminum Neurotoxicity — Potential Role in the Pathogenesis of Neurofibrillary Tangle Formation Daniel P. Perl and William W. Pendlebury ABSTRACT: Alzheimer's disease is a progressive neurodegenerative disease characterized neuropathologically by the development of large numbers of neurofibrillary tangles in certain neuronal populations of affected brains. This paper presents a review of the available evidence which suggests that aluminum is associated with Alzheimer's disease and specifically with the development of the neurofibrillary tangle. Aluminum salts innoculated into experi­ mental animals produce neurofilamentous lesions which are similar, though not identical, to the neurofibrillary tangle of man. Although a few reports have suggested evidence of increased amounts of aluminum in the brains of Alzheimer's disease victims, such bulk analysis studies have been difficult to replicate. Using scanning electron microscopy with x-ray spectrometry, we have identified accumulations of aluminum in neurofibrillary tangle-bearing neurons of Alzheimer's disease. Similar accumulations have been identified in the neurofibrillary tangle-bearing neurons found in the brains of indigenous natives of Guam who suffer from parkinsonism with dementia and amyotrophic lateral sclerosis. This ongoing research still cannot ascribe a causal role of aluminum in the pathogenesis of neurofibrillary tangle formation; however, it does suggest that environmental factors may play an important part in the formation of this abnormality. RESUME: La neurotoxicity de Paluminium: son role possible dans la pathogenese de la formation des enchevetrements neurofibrillaires. La maladie d'Alzheimer est une maladie neurodegenerative progressive caracterisee au point de vue anatomo-pathologique par le developpement d'un grand nombre d'enchevetrements neurofibrillaires au sein de certaines populations de neurones dans le cerveau des sujets atteints.
    [Show full text]
  • Formation of Hirano Bodies in Cell Culture 1941
    Research Article 1939 Formation of Hirano bodies in Dictyostelium and mammalian cells induced by expression of a modified form of an actin-crosslinking protein Andrew G. Maselli, Richard Davis, Ruth Furukawa and Marcus Fechheimer* Department of Cellular Biology, University of Georgia, Athens, Georgia 30602, USA *Author for correspondence (e-mail: [email protected]) Accepted 26 February 2002 Journal of Cell Science 115, 1939-1952 (2002) © The Company of Biologists Ltd Summary We report the serendipitous development of the first pathological conditions. Furthermore, expression of the cultured cell models of Hirano bodies. Myc-epitope-tagged CT fragment in murine L cells results in F-actin forms of the 34 kDa actin bundling protein (amino acids 1- rearrangements characterized by loss of stress fibers, 295) and the CT fragment (amino acids 124-295) of the 34 accumulation of numerous punctate foci, and large kDa protein that exhibits activated actin binding and perinuclear aggregates, the Hirano bodies. Thus, failure to calcium-insensitive actin filament crosslinking activity regulate the activity and/or affinity of an actin crosslinking were expressed in Dictyostelium and mammalian cells to protein can provide a signal for formation of Hirano bodies. assess the behavior of these modified forms in vivo. More generally, formation of Hirano bodies is a cellular Dictyostelium cells expressing the CT-myc fragment: (1) response to or a consequence of aberrant function of the form ellipsoidal regions that contain ordered assemblies of actin cytoskeleton. The results reveal that formation of F-actin, CT-myc, myosin II, cofilin and α-actinin; (2) grow Hirano bodies is not necessarily related to cell death.
    [Show full text]
  • The Novel Adaptor Protein, Mti1p, and Vrp1p, a Homolog of Wiskott-Aldrich Syndrome Protein-Interacting Protein
    Copyright 2002 by the Genetics Society of America The Novel Adaptor Protein, Mti1p, and Vrp1p, a Homolog of Wiskott-Aldrich Syndrome Protein-Interacting Protein (WIP), May Antagonistically Regulate Type I Myosins in Saccharomyces cerevisiae Junko Mochida, Takaharu Yamamoto, Konomi Fujimura-Kamada and Kazuma Tanaka1 Division of Molecular Interaction, Institute for Genetic Medicine, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, 060-0815, Japan Manuscript received July 31, 2001 Accepted for publication January 7, 2002 ABSTRACT Type I myosins in yeast, Myo3p and Myo5p (Myo3/5p), are involved in the reorganization of the actin cytoskeleton. The SH3 domain of Myo5p regulates the polymerization of actin through interactions with both Las17p, a homolog of mammalian Wiskott-Aldrich syndrome protein (WASP), and Vrp1p, a homolog of WASP-interacting protein (WIP). Vrp1p is required for both the localization of Myo5p to cortical patch- like structures and the ATP-independent interaction between the Myo5p tail region and actin filaments. We have identified and characterized a new adaptor protein, Mti1p (Myosin tail region-interacting protein), which interacts with the SH3 domains of Myo3/5p. Mti1p co-immunoprecipitated with Myo5p and Mti1p- GFP co-localized with cortical actin patches. A null mutation of MTI1 exhibited synthetic lethal phenotypes with mutations in SAC6 and SLA2, which encode actin-bundling and cortical actin-binding proteins, respectively. Although the mti1 null mutation alone did not display any obvious phenotype, it suppressed vrp1 mutation phenotypes, including temperature-sensitive growth, abnormally large cell morphology, defects in endocytosis and salt-sensitive growth. These results suggest that Mti1p and Vrp1p antagonistically regulate type I myosin functions.
    [Show full text]
  • Chronic Traumatic Encephalopathy-Like Abnormalities in a Routine Neuropathology Service
    J Neuropathol Exp Neurol Vol. 75, No. 12, December 2016, pp. 1145–1154 doi: 10.1093/jnen/nlw092 ORIGINAL ARTICLE Chronic Traumatic Encephalopathy-Like Abnormalities in a Routine Neuropathology Service Shawna Noy, MD, Sherry Krawitz, MD, PhD, and Marc R. Del Bigio, MD, PhD, FRCPC Downloaded from https://academic.oup.com/jnen/article-abstract/75/12/1145/2452334 by guest on 07 September 2018 sports including boxing, American football, soccer, ice Abstract hockey, wrestling and rugby, as well as in military personnel Chronic traumatic encephalopathy (CTE) has been described who have had exposure to blast or concussive injury (3–6). mainly in professional athletes and military personnel and is charac- McKeeetal(1) categorized the histological findings of CTE terized by deposition of hyperphosphorylated tau at the depths of into 4 stages. Their evidence suggests that CTE begins at the cortical sulci and around blood vessels. To assess CTE-like changes depths of cortical sulci in a perivascular distribution, and in a routine neuropathology service, we prospectively examined 111 spreads to involve widespread regions of the central nervous brains (age 18–60 years). The presence of tau-immunoreactive de- system. The pathogenesis of CTE is not well understood. posits was staged using guidelines described by others and was cor- Repetitive mild brain trauma is the postulated underlying related with the medical history. 72/111 cases were negative for stimulus (3). Tau (which is encoded by the MAPT gene) is an CTE-like changes; 34/111 were CTE stage <1; 3/111 were CTE axonal protein that promotes microtubule assembly and stabil- stage 1; and 2/111 were CTE stage 2.
    [Show full text]
  • Interaction Between Fragments of Tau Protein Investigated by Force Spectroscopy Using AFM
    Interaction between Fragments of Tau Protein Investigated by Force Spectroscopy Using AFM by Anad Mohamed Afhaima Bachelor of Science, Sirte University Master of Science, Sirte University A Dissertation submitted to the Department of Chemistry at Florida Institute of Technology in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Chemistry Melbourne, Florida December 2017 III Interaction between Fragments of Tau Protein Investigated by Force Spectroscopy Using AFM a dissertation by Anad Mohamed Afhaima Approved as to style and content _______________________________________ Boris Akhremitchev, Ph.D. Committee Chairperson Associate Professor, Department of Chemistry ________________________________________ Nasri Nesnas, Ph.D. Associate Professor, Department of Chemistry ________________________________________ Yi Liao, Ph.D. Associate Professor, Department of Chemistry ________________________________________ David Carroll, Ph.D. Associate Professor, Department of Biological Sciences ________________________________________ Michael Freund, Ph.D. Professor and Head, Department of Chemistry IV Abstract Interaction between Fragments of Tau Protein Investigated by Force Spectroscopy Using AFM by Anad Mohamed Afhaima Major Advisor: Boris Akhremitchev, Ph.D. Over the last couple of decades, there has been rapidly growing interest in research of natively unfolded proteins. Some proteins from this group are implicated in a number of neurodegenerative diseases. One group of neurodegenerative diseases, taupathies, is associated with tau protein. A number of biophysical and spectroscopic studies have revealed that tau protein can expand to a largely extended state and to transition rapidly between many different conformations. Although many of the techniques that elucidate structure of macromolecules have provided important information about the folded states of proteins, important information about the transition between the extended conformation states remain obscure.
    [Show full text]
  • Structures of Filaments from Pick's Disease Reveal a Novel Tau
    bioRxiv preprint doi: https://doi.org/10.1101/302216; this version posted April 16, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY 4.0 International license. 1 Structures of filaments from Pick’s disease reveal a 2 novel tau protein fold 3 4 Benjamin Falcon1, Wenjuan Zhang1, Alexey G. Murzin1, Garib Murshudov1, Holly J. 5 Garringer2, Ruben Vidal2, R. Anthony Crowther1, Bernardino Ghetti2, Sjors H.W. 6 Scheres1* & Michel Goedert1* 7 8 1 MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge, CB2 0QH, UK 9 2 Department of Pathology and Laboratory Medicine, Indiana University School of 10 Medicine, Indianapolis, IN 46202, USA 11 12 * Correspondence to: [email protected] and [email protected], these 13 authors jointly supervised this work 14 15 16 The ordered assembly of tau protein into abnormal filamentous inclusions 17 underlies many human neurodegenerative diseases1. Tau assemblies 18 appear to spread through specific neural networks in each disease2, with 19 short filaments having the greatest seeding activity3. The abundance of tau 20 inclusions strongly correlates with disease symptoms4. Six tau isoforms are 21 expressed in normal adult human brain - three isoforms with four 22 microtubule-binding repeats each (4R tau) and three isoforms lacking the 23 second repeat (3R tau)1. In various diseases, tau filaments can be 24 composed of either 3R tau or 4R tau, or of both 3R and 4R tau.
    [Show full text]
  • Epigenetic Modifications to Cytosine and Alzheimer's Disease
    University of Kentucky UKnowledge Theses and Dissertations--Chemistry Chemistry 2017 EPIGENETIC MODIFICATIONS TO CYTOSINE AND ALZHEIMER’S DISEASE: A QUANTITATIVE ANALYSIS OF POST-MORTEM TISSUE Elizabeth M. Ellison University of Kentucky, [email protected] Digital Object Identifier: https://doi.org/10.13023/ETD.2017.398 Right click to open a feedback form in a new tab to let us know how this document benefits ou.y Recommended Citation Ellison, Elizabeth M., "EPIGENETIC MODIFICATIONS TO CYTOSINE AND ALZHEIMER’S DISEASE: A QUANTITATIVE ANALYSIS OF POST-MORTEM TISSUE" (2017). Theses and Dissertations--Chemistry. 86. https://uknowledge.uky.edu/chemistry_etds/86 This Doctoral Dissertation is brought to you for free and open access by the Chemistry at UKnowledge. It has been accepted for inclusion in Theses and Dissertations--Chemistry by an authorized administrator of UKnowledge. For more information, please contact [email protected]. STUDENT AGREEMENT: I represent that my thesis or dissertation and abstract are my original work. Proper attribution has been given to all outside sources. I understand that I am solely responsible for obtaining any needed copyright permissions. I have obtained needed written permission statement(s) from the owner(s) of each third-party copyrighted matter to be included in my work, allowing electronic distribution (if such use is not permitted by the fair use doctrine) which will be submitted to UKnowledge as Additional File. I hereby grant to The University of Kentucky and its agents the irrevocable, non-exclusive, and royalty-free license to archive and make accessible my work in whole or in part in all forms of media, now or hereafter known.
    [Show full text]