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  1. Article ; Online: Dopamine transporter is enriched in filopodia and induces filopodia formation.

    Caltagarone, John / Ma, Shiqi / Sorkin, Alexander

    Molecular and cellular neurosciences

    2015  Volume 68, Page(s) 120–130

    Abstract: Dopamine transporter (DAT, SLC6A3) controls dopamine (DA) neurotransmission by mediating re-uptake of extracellular DA into DA neurons. DA uptake depends on the amount of DAT at the cell surface, and is therefore regulated by DAT subcellular distribution. ...

    Abstract Dopamine transporter (DAT, SLC6A3) controls dopamine (DA) neurotransmission by mediating re-uptake of extracellular DA into DA neurons. DA uptake depends on the amount of DAT at the cell surface, and is therefore regulated by DAT subcellular distribution. Hence we used spinning disk confocal microscopy to demonstrate DAT localization in membrane protrusions that contained filamentous actin and myosin X (MyoX), a molecular motor located in filopodia tips, thus confirming that these protrusions are filopodia. DAT was enriched in filopodia. In contrast, R60A and W63A DAT mutants with disrupted outward-facing conformation were not accumulated in filopodia, suggesting that this conformation is necessary for DAT filopodia targeting. Three independent approaches of filopodia counting showed that DAT expression leads to an increase in the number of filopodia per cell, indicating that DAT can induce filopodia formation. Depletion of MyoX by RNA interference resulted in a significant loss of filopodia but did not completely eliminate filopodia, implying that DAT-enriched filopodia can be formed without MyoX. In cultured postnatal DA neurons MyoX was mainly localized to growth cones that displayed highly dynamic DAT-containing filopodia. We hypothesize that the concave shape of the DAT molecule functions as the targeting determinant for DAT accumulation in outward-curved membrane domains, and may also allow high local concentrations of DAT to induce an outward membrane bending. Such targeting and membrane remodeling capacities may be part of the mechanism responsible for DAT enrichment in the filopodia and its targeting to the axonal processes of DA neurons.
    MeSH term(s) Actins/genetics ; Actins/metabolism ; Animals ; Animals, Newborn ; Axons/drug effects ; Axons/physiology ; Cell Membrane/drug effects ; Cell Membrane/metabolism ; Dopamine/metabolism ; Dopamine Plasma Membrane Transport Proteins/genetics ; Dopamine Plasma Membrane Transport Proteins/metabolism ; Imaging, Three-Dimensional ; In Vitro Techniques ; Luminescent Proteins/genetics ; Luminescent Proteins/metabolism ; Mesencephalon/cytology ; Mice ; Mice, Transgenic ; Mutation/genetics ; Myosins/genetics ; Myosins/metabolism ; Neurons/cytology ; Organ Culture Techniques ; Pseudopodia/drug effects ; Pseudopodia/physiology ; RNA, Small Interfering/pharmacology ; Receptor, Epidermal Growth Factor/genetics ; Receptor, Epidermal Growth Factor/metabolism
    Chemical Substances Actins ; Dopamine Plasma Membrane Transport Proteins ; Luminescent Proteins ; Myo10 protein, mouse ; RNA, Small Interfering ; EGFR protein, mouse (EC 2.7.10.1) ; Receptor, Epidermal Growth Factor (EC 2.7.10.1) ; Myosins (EC 3.6.4.1) ; Dopamine (VTD58H1Z2X)
    Language English
    Publishing date 2015-09
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Video-Audio Media
    ZDB-ID 1046640-x
    ISSN 1095-9327 ; 1044-7431
    ISSN (online) 1095-9327
    ISSN 1044-7431
    DOI 10.1016/j.mcn.2015.04.005
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Flotillins regulate membrane mobility of the dopamine transporter but are not required for its protein kinase C dependent endocytosis.

    Sorkina, Tatiana / Caltagarone, John / Sorkin, Alexander

    Traffic (Copenhagen, Denmark)

    2013  Volume 14, Issue 6, Page(s) 709–724

    Abstract: Flotillins were proposed to mediate clathrin-independent endocytosis, and recently, flotillin-1 was implicated in the protein kinase C (PKC)-triggered endocytosis of the dopamine transporter (DAT). Since endocytosis of DAT was previously shown to be ... ...

    Abstract Flotillins were proposed to mediate clathrin-independent endocytosis, and recently, flotillin-1 was implicated in the protein kinase C (PKC)-triggered endocytosis of the dopamine transporter (DAT). Since endocytosis of DAT was previously shown to be clathrin-mediated, we re-examined the role of clathrin coat proteins and flotillin in DAT endocytosis using DAT tagged with the hemagglutinin epitope (HA) in the extracellular loop and a quantitative HA antibody uptake assay. Depletion of flotillin-1, flotillin-2 or both flotillins together by small interfering RNAs (siRNAs) did not inhibit PKC-dependent internalization and degradation of HA-DAT. In contrast, siRNAs to clathrin heavy chain and μ2 subunit of clathrin adaptor complex AP-2 as well as a dynamin inhibitor Dyngo-4A significantly decreased PKC-dependent endocytosis of HA-DAT. Similarly, endocytosis and degradation of DAT that is not epitope-tagged were highly sensitive to the clathrin siRNAs and dynamin inhibition but were not affected by flotillin knockdown. Very little co-localization of DAT with flotillins was observed in cells ectopically expressing DAT and in cultured mouse dopaminergic neurons. Depletion of flotillins increased diffusion rates of HA-DAT in the plasma membrane, suggesting that flotillin-organized microdomains may regulate the lateral mobility of DAT. We propose that clathrin-mediated endocytosis is the major pathway of PKC-dependent internalization of DAT, and that flotillins may modulate functional association of DAT with plasma membrane rafts rather than mediate DAT endocytosis.
    MeSH term(s) Animals ; Cell Membrane/metabolism ; Cells, Cultured ; Clathrin/genetics ; Clathrin/metabolism ; Dopamine Plasma Membrane Transport Proteins/metabolism ; Dopaminergic Neurons/metabolism ; Dynamins/antagonists & inhibitors ; Endocytosis ; HEK293 Cells ; Humans ; Hydrazones/pharmacology ; Membrane Proteins/genetics ; Membrane Proteins/metabolism ; Mice ; Naphthols/pharmacology ; Protein Kinase C/genetics ; Protein Kinase C/metabolism ; Protein Transport ; Proteolysis ; RNA, Small Interfering/genetics
    Chemical Substances Clathrin ; Dopamine Plasma Membrane Transport Proteins ; Hydrazones ; Membrane Proteins ; Naphthols ; RNA, Small Interfering ; dyngo-4a ; flotillins ; Protein Kinase C (EC 2.7.11.13) ; Dynamins (EC 3.6.5.5)
    Language English
    Publishing date 2013-03-11
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 1483852-7
    ISSN 1600-0854 ; 1398-9219
    ISSN (online) 1600-0854
    ISSN 1398-9219
    DOI 10.1111/tra.12059
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Altered subcellular distribution of c-Abl in Alzheimer's disease.

    Jing, Zheng / Caltagarone, John / Bowser, Robert

    Journal of Alzheimer's disease : JAD

    2009  Volume 17, Issue 2, Page(s) 409–422

    Abstract: c-Abl is a non-receptor tyrosine kinase that participates in multiple signaling pathways linking the cell surface, cytoskeleton, and the nucleus. Recent in vitro studies have also linked c-Abl to amyloid-beta-induced toxicity and tau phosphorylation. To ... ...

    Abstract c-Abl is a non-receptor tyrosine kinase that participates in multiple signaling pathways linking the cell surface, cytoskeleton, and the nucleus. Recent in vitro studies have also linked c-Abl to amyloid-beta-induced toxicity and tau phosphorylation. To further characterize a potential role of c-Abl in Alzheimer's disease (AD), we examined the expression and distribution of total and phosphorylated forms of c-Abl in the hippocampus of AD and control subjects. Laser scanning confocal microscopy was used to examine the colocalization of c-Abl with AD pathology. Our results demonstrate alterations in the presence and distribution of c-Abl and phosphorylated isoforms of c-Abl within the hippocampus during AD. Total unphosphorylated c-Abl was highest in non-demented control hippocampus. Activated isoforms of c-Abl were most abundant in AD hippocampus and co-localized with AD pathology, including granulovacuolar degeneration bodies, c-Abl interacts with phosphorylated tau in AD brain and may contribute to the formation of tau pathology. These studies demonstrate altered activation and distribution of c-Abl during AD, suggesting a role for c-Abl in Abeta signal transduction and generation of tau pathology in AD.
    MeSH term(s) Aged ; Aged, 80 and over ; Alzheimer Disease/pathology ; Amyloid/metabolism ; Analysis of Variance ; Case-Control Studies ; Female ; Hippocampus/metabolism ; Hippocampus/pathology ; Humans ; Immunoprecipitation/methods ; Male ; Microscopy, Confocal/methods ; Middle Aged ; Neurofilament Proteins/metabolism ; Phosphorylation ; Proto-Oncogene Proteins c-abl/metabolism ; Subcellular Fractions/metabolism ; Threonine/metabolism ; Tyrosine/metabolism ; tau Proteins/metabolism
    Chemical Substances Amyloid ; Neurofilament Proteins ; tau Proteins ; neurofilament protein H (108688-71-7) ; Threonine (2ZD004190S) ; Tyrosine (42HK56048U) ; Proto-Oncogene Proteins c-abl (EC 2.7.10.2)
    Language English
    Publishing date 2009-04-10
    Publishing country Netherlands
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 1440127-7
    ISSN 1875-8908 ; 1387-2877
    ISSN (online) 1875-8908
    ISSN 1387-2877
    DOI 10.3233/JAD-2009-1062
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  4. Article ; Online: Brain Region-Specific Trafficking of the Dopamine Transporter.

    Block, Ethan R / Nuttle, Jacob / Balcita-Pedicino, Judith Joyce / Caltagarone, John / Watkins, Simon C / Sesack, Susan R / Sorkin, Alexander

    The Journal of neuroscience : the official journal of the Society for Neuroscience

    2015  Volume 35, Issue 37, Page(s) 12845–12858

    Abstract: The dopamine (DA) transporter (DAT) controls dopaminergic neurotransmission by removing extracellular DA. Although DA reuptake is proposed to be regulated by DAT traffic to and from the cell surface, the membrane trafficking system involved in the ... ...

    Abstract The dopamine (DA) transporter (DAT) controls dopaminergic neurotransmission by removing extracellular DA. Although DA reuptake is proposed to be regulated by DAT traffic to and from the cell surface, the membrane trafficking system involved in the endocytic cycling of DAT in the intact mammalian brain has not been characterized. Hence, we performed immunolabeling and quantitative analysis of the subcellular and regional distribution of DAT using the transgenic knock-in mouse expressing hemagglutinin (HA) epitope-tagged DAT (HA-DAT) and by using a combination of electron microscopy and a novel method for immunofluorescence labeling of HA-DAT in acute sagittal brain slices. Both approaches demonstrated that, in midbrain somatodendritic regions, HA-DAT was present in the plasma membrane, endoplasmic reticulum, and Golgi complex, with a small fraction in early and recycling endosomes and an even smaller fraction in late endosomes and lysosomes. In the striatum and in axonal tracts between the midbrain and striatum, HA-DAT was detected predominantly in the plasma membrane, and quantitative analysis revealed increased DAT density in striatal compared with midbrain plasma membranes. Endosomes were strikingly rare and lysosomes were absent in striatal axons, in which there was little intracellular HA-DAT. Acute administration of amphetamine in vivo (60 min) or to slices ex vivo (10-60 min) did not result in detectable changes in DAT distribution. Altogether, these data provide evidence for regional differences in DAT plasma membrane targeting and retention and suggest a surprisingly low level of endocytic trafficking of DAT in the striatum along with limited DAT endocytic activity in somatodendritic areas.
    Significance statement: The dopamine transporter (DAT) is the key regulator of the dopamine neurotransmission in the CNS. In the present study, we developed a new approach for studying DAT localization and dynamics in intact neurons in acute sagittal brain slices from the knock-in mouse expressing epitope-tagged DAT. For the first time, the fluorescence imaging analysis of DAT was combined with the immunogold labeling of DAT and quantitative electron microscopy. In contrast to numerous studies of DAT trafficking in heterologous expression systems and dissociated cultured neurons, studies in intact neurons revealed a surprisingly low amount of endocytic trafficking of DAT at steady state and after acute amphetamine treatment and suggested that non-vesicular transport could be the main mechanism establishing DAT distribution within the dopaminergic neuron.
    MeSH term(s) Amphetamine/pharmacology ; Animals ; Axons/chemistry ; Axons/ultrastructure ; Cell Compartmentation ; Cells, Cultured ; Corpus Striatum/metabolism ; Corpus Striatum/pathology ; Dopamine/metabolism ; Dopamine Plasma Membrane Transport Proteins/metabolism ; Dopaminergic Neurons/metabolism ; Endocytosis ; Female ; Gene Knock-In Techniques ; HEK293 Cells ; Humans ; Immunohistochemistry ; Male ; Mice ; Mice, Transgenic ; Microscopy, Electron ; Microscopy, Fluorescence ; Protein Transport ; Rats ; Subcellular Fractions
    Chemical Substances Dopamine Plasma Membrane Transport Proteins ; Amphetamine (CK833KGX7E) ; Dopamine (VTD58H1Z2X)
    Language English
    Publishing date 2015-09-12
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 604637-x
    ISSN 1529-2401 ; 0270-6474
    ISSN (online) 1529-2401
    ISSN 0270-6474
    DOI 10.1523/JNEUROSCI.1391-15.2015
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Focal adhesions regulate Abeta signaling and cell death in Alzheimer's disease.

    Caltagarone, John / Jing, Zheng / Bowser, Robert

    Biochimica et biophysica acta

    2006  Volume 1772, Issue 4, Page(s) 438–445

    Abstract: Alzheimer's disease (AD) is a neurodegenerative disorder that results from a loss of synaptic transmission and ultimately cell death. The presenting pathology of AD includes neuritic plaques composed of beta-amyloid peptide (Abeta) and neurofibrillary ... ...

    Abstract Alzheimer's disease (AD) is a neurodegenerative disorder that results from a loss of synaptic transmission and ultimately cell death. The presenting pathology of AD includes neuritic plaques composed of beta-amyloid peptide (Abeta) and neurofibrillary tangles composed of hyperphosphorylated tau, with neuronal loss in specific brain regions. However, the mechanisms that induce neuronal cell loss remain elusive. Focal adhesion (FA) proteins assemble into intracellular complexes involved in integrin-mediated communication between the extracellular matrix and the actin cytoskeleton, regulating many cell physiological processes including the cell cycle. Interestingly, recent studies report that integrins bind to Abeta fibrils, mediating Abeta signal transmission from extracellular sites of Abeta deposits into the cell and ultimately to the nucleus. In this review, we will discuss the Abeta induced integrin/FA signaling pathways that mediate cell cycle activation and cell death.
    MeSH term(s) Alzheimer Disease/pathology ; Amyloid beta-Peptides/physiology ; Cell Adhesion/physiology ; Cell Cycle ; Cell Death ; Cell Survival ; Humans ; Integrins/physiology ; Neurons/cytology ; Neurons/pathology ; Signal Transduction ; Transcription, Genetic
    Chemical Substances Amyloid beta-Peptides ; Integrins
    Language English
    Publishing date 2006-11-30
    Publishing country Netherlands
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Review
    ZDB-ID 60-7
    ISSN 1879-2596 ; 1879-260X ; 1872-8006 ; 1879-2642 ; 1879-2618 ; 1879-2650 ; 0006-3002 ; 0005-2728 ; 0005-2736 ; 0304-4165 ; 0167-4838 ; 1388-1981 ; 0167-4889 ; 0167-4781 ; 0304-419X ; 1570-9639 ; 0925-4439 ; 1874-9399
    ISSN (online) 1879-2596 ; 1879-260X ; 1872-8006 ; 1879-2642 ; 1879-2618 ; 1879-2650
    ISSN 0006-3002 ; 0005-2728 ; 0005-2736 ; 0304-4165 ; 0167-4838 ; 1388-1981 ; 0167-4889 ; 0167-4781 ; 0304-419X ; 1570-9639 ; 0925-4439 ; 1874-9399
    DOI 10.1016/j.bbadis.2006.11.007
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Paxillin and hydrogen peroxide-inducible clone 5 expression and distribution in control and Alzheimer disease hippocampi.

    Caltagarone, John / Hamilton, Ronald L / Murdoch, Geoffrey / Jing, Zheng / DeFranco, Donald B / Bowser, Robert

    Journal of neuropathology and experimental neurology

    2010  Volume 69, Issue 4, Page(s) 356–371

    Abstract: Hydrogen peroxide-inducible clone 5 (Hic-5) and paxillin are members of the Group III LIM domain protein family that localize to both cell nuclei and focal adhesions and link integrin-mediated signaling to the actin cytoskeleton. Prior in vitro studies ... ...

    Abstract Hydrogen peroxide-inducible clone 5 (Hic-5) and paxillin are members of the Group III LIM domain protein family that localize to both cell nuclei and focal adhesions and link integrin-mediated signaling to the actin cytoskeleton. Prior in vitro studies have implicated paxillin in beta-amyloid-induced cell death, but little is known about the expression and function of Hic-5 and paxillin in the brain. We performed a blinded retrospective cross-sectional study of Hic-5 and paxillin expression in the hippocampi of Alzheimer disease (AD) and control subjects using immunohistochemistry and laser scanning confocal microscopy. The analysis included assessment of the expression of phosphorylated isoforms of paxillin that reflect activation of distinct signaling pathways. We found changes in the subcellular distribution of Hic-5, paxillin, and specific phosphorylated isoforms of paxillin in the AD brains. The Hic-5 and phosphorylated isoforms of paxillin colocalized with neurofibrillary tangles. Paxillin was predominantly found in reactive astrocytes in the AD hippocampi, and activated paxillin was also detected in granulovacuolar degeneration bodies in AD. These data indicate that these important scaffolding proteins that link various intracellular signaling pathways to the extracellular matrix are modified and have altered subcellular distribution in AD.
    MeSH term(s) Aged ; Alzheimer Disease/pathology ; Alzheimer Disease/physiopathology ; Amyloid beta-Peptides/metabolism ; Antigens, CD/metabolism ; Antigens, Differentiation, Myelomonocytic/metabolism ; Case-Control Studies ; Female ; Gene Expression/physiology ; Hippocampus/metabolism ; Humans ; Immunoprecipitation/methods ; Intracellular Signaling Peptides and Proteins/metabolism ; LIM Domain Proteins ; Male ; Middle Aged ; Nerve Tissue Proteins/metabolism ; Paxillin/metabolism ; Phosphorylation/physiology ; Protein Isoforms/metabolism ; Statistics, Nonparametric ; tau Proteins/metabolism
    Chemical Substances Amyloid beta-Peptides ; Antigens, CD ; Antigens, Differentiation, Myelomonocytic ; CD68 antigen, human ; Intracellular Signaling Peptides and Proteins ; LIM Domain Proteins ; Nerve Tissue Proteins ; Paxillin ; Protein Isoforms ; TGFB1I1 protein, human ; tau Proteins
    Language English
    Publishing date 2010-04-23
    Publishing country England
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 3088-0
    ISSN 1554-6578 ; 0022-3069
    ISSN (online) 1554-6578
    ISSN 0022-3069
    DOI 10.1097/NEN.0b013e3181d53d98
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: DNA damage induces cdk2 protein levels and histone H2B phosphorylation in SH-SY5Y neuroblastoma cells.

    Yu, Xiaoyi / Caltagarone, John / Smith, Mark A / Bowser, Robert

    Journal of Alzheimer's disease : JAD

    2005  Volume 8, Issue 1, Page(s) 7–21

    Abstract: DNA damage and activation of the cell cycle have been implicated in numerous neurodegenerative diseases, including Alzheimer disease, Parkinson's disease, and amyotrophic lateral sclerosis. To better understand the role of cell cycle proteins in DNA- ... ...

    Abstract DNA damage and activation of the cell cycle have been implicated in numerous neurodegenerative diseases, including Alzheimer disease, Parkinson's disease, and amyotrophic lateral sclerosis. To better understand the role of cell cycle proteins in DNA-damage induced neuronal cell death, we examined various cell cycle proteins during camptothecin-induced death of human neuroblastoma cells. We report a rapid induction of p53 and increased expression of p21, concurrent with reduced levels of many cell cycle proteins that regulate G1 to S phase cell cycle progression. However, we found increased levels of cdk2 and cyclin E, and formation of a cyclin E-cdk2-p21 protein complex. DNA damage failed to induce activation and progression of the cell cycle. Finally, camptothecin-induced neuronal cell death occurred concurrent with phosphorylation of histone H2B. Pretreatment of cells with cdk inhibitor olomoucine impeded cdk2-cyclin E accumulation, but not the induction of p53. Olomucine concurrently delayed histone H2B phosphorylation, caspase-3 activation and cell death. These findings suggest that DNA-damage of differentiated neuroblastoma cells induces a rapid p53-mediated inhibition of cell cycle progression and induction of cdk2-cyclin E, followed by caspase-3 activation, phosphorylation of histone and cell death.
    MeSH term(s) Camptothecin/pharmacology ; Caspase 3 ; Caspases/genetics ; Cell Cycle/genetics ; Cell Cycle Proteins/genetics ; Cell Death/genetics ; Cell Line, Tumor ; Cyclin E/genetics ; Cyclin-Dependent Kinase 2/genetics ; DNA Damage/physiology ; Enzyme Induction/genetics ; Gene Expression Regulation/drug effects ; Genes, p53/genetics ; Histones/genetics ; Humans ; In Vitro Techniques ; Kinetin/pharmacology ; Neuroblastoma/pathology ; Neurons/drug effects ; Phosphorylation ; Tumor Cells, Cultured/metabolism
    Chemical Substances Cell Cycle Proteins ; Cyclin E ; Histones ; olomoucine (6A839B2HYS) ; Cyclin-Dependent Kinase 2 (EC 2.7.11.22) ; CASP3 protein, human (EC 3.4.22.-) ; Caspase 3 (EC 3.4.22.-) ; Caspases (EC 3.4.22.-) ; Kinetin (P39Y9652YJ) ; Camptothecin (XT3Z54Z28A)
    Language English
    Publishing date 2005-09-01
    Publishing country Netherlands
    Document type Journal Article ; Research Support, N.I.H., Extramural ; Research Support, U.S. Gov't, P.H.S.
    ZDB-ID 1440127-7
    ISSN 1875-8908 ; 1387-2877
    ISSN (online) 1875-8908
    ISSN 1387-2877
    DOI 10.3233/jad-2005-8102
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  8. Article: Functional repression of cAMP response element in 6-hydroxydopamine-treated neuronal cells.

    Chalovich, Elisabeth M / Zhu, Jian-hui / Caltagarone, John / Bowser, Robert / Chu, Charleen T

    The Journal of biological chemistry

    2006  Volume 281, Issue 26, Page(s) 17870–17881

    Abstract: Impaired survival signaling may represent a central mechanism in neurodegeneration. 6-Hydroxydopamine (6-OHDA) is an oxidative neurotoxin used to injure catecholaminergic cells of the central and peripheral nervous systems. Although 6-OHDA elicits ... ...

    Abstract Impaired survival signaling may represent a central mechanism in neurodegeneration. 6-Hydroxydopamine (6-OHDA) is an oxidative neurotoxin used to injure catecholaminergic cells of the central and peripheral nervous systems. Although 6-OHDA elicits phosphorylation of several kinases, downstream transcriptional effects that influence neuronal cell death are less defined. The cAMP response element (CRE) is present in the promoter sequences of several important neuronal survival factors. Treatment of catecholaminergic neuronal cell lines (B65 and SH-SY5Y) with 6-OHDA resulted in repression of basal CRE transactivation. Message levels of CRE-driven genes such as brain-derived neurotrophic factor and the survival factor Bcl-2 were decreased in 6-OHDA-treated cells, but message levels of genes lacking CRE sequences were not affected. Repression of CRE could be reversed by delayed treatment with cAMP several hours after initiation of 6-OHDA injury. Furthermore, restoration of CRE-driven transcription was associated with significant neuroprotection. In contrast to observations in other model systems, the mechanism of CRE repression did not involve decreased phosphorylation of its binding protein CREB. Instead, total CREB and phospho-CREB (pCREB) were increased in the cytoplasm and decreased in the nucleus of 6-OHDA-treated cells. 6-OHDA also decreased nuclear pCREB in dopaminergic neurons of primary mouse midbrain cultures. Co-treatment with cAMP promoted/restored nuclear localization of pCREB in both immortalized and primary culture systems. Increased cytoplasmic pCREB was observed in degenerating human Parkinson/Lewy body disease substantia nigra neurons but not in age-matched controls. Notably, cytoplasmic accumulation of activated upstream CREB kinases has been observed previously in both 6-OHDA-treated cells and degenerating human neurons, supporting a potential role for impaired nuclear import of phosphorylated signaling proteins.
    MeSH term(s) Animals ; Cell Death/physiology ; Cell Line, Tumor ; Cell Nucleus/physiology ; Cyclic AMP/metabolism ; Cyclic AMP/pharmacology ; Cyclic AMP Response Element-Binding Protein/metabolism ; Cytoplasm/metabolism ; Dopamine/physiology ; Fluorescent Antibody Technique ; Humans ; Mesencephalon/cytology ; Mice ; Mice, Inbred C57BL ; Neuroblastoma ; Neurons/cytology ; Neurons/drug effects ; Neurons/physiology ; Oxidative Stress/physiology ; Oxidopamine/pharmacology ; Parkinson Disease/pathology ; Parkinson Disease/physiopathology ; Phosphorylation/drug effects ; Promoter Regions, Genetic/physiology ; Response Elements/physiology ; Sympatholytics/pharmacology ; Transcriptional Activation/physiology
    Chemical Substances Cyclic AMP Response Element-Binding Protein ; Sympatholytics ; Oxidopamine (8HW4YBZ748) ; Cyclic AMP (E0399OZS9N) ; Dopamine (VTD58H1Z2X)
    Language English
    Publishing date 2006-04-18
    Publishing country United States
    Document type Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 2997-x
    ISSN 1083-351X ; 0021-9258
    ISSN (online) 1083-351X
    ISSN 0021-9258
    DOI 10.1074/jbc.M602632200
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  9. Article: Fetal Alz-50 clone 1 interacts with the human orthologue of the Kelch-like Ech-associated protein.

    Strachan, Gordon D / Morgan, Kathleen L / Otis, Linda L / Caltagarone, John / Gittis, Aryn / Bowser, Robert / Jordan-Sciutto, Kelly L

    Biochemistry

    2004  Volume 43, Issue 38, Page(s) 12113–12122

    Abstract: The fetal Alz-50 reactive clone 1 (FAC1) protein exhibits altered expression and subcellular localization during neuronal development and neurodegenerative diseases such as Alzheimer's disease. Using the yeast two-hybrid screen, the human orthologue of ... ...

    Abstract The fetal Alz-50 reactive clone 1 (FAC1) protein exhibits altered expression and subcellular localization during neuronal development and neurodegenerative diseases such as Alzheimer's disease. Using the yeast two-hybrid screen, the human orthologue of Keap1 (hKeap1) was identified as a FAC1 interacting protein. Keap1 is an important regulator of the oxidative stress response pathway through its interaction with the Nrf family of transcription factors. An interaction between full-length FAC1 and hKeap1 proteins has been demonstrated, and the FAC1 binding domain of hKeap1 has been identified as the Kelch repeats. In addition, FAC1 colocalizes with endogenous Keap1 within the cytoplasm of PT67 cells. Exogenously introduced eGFP:hKeap1 fusion protein redistributed FAC1 to colocalize with eGFP:hKeap1 in perinuclear, spherical structures. The interaction between FAC1 and hKeap1 is reduced by competition with the Nrf2 protein. However, competition by Nrf2 for hKeap1 is reduced by diethylmaleate (DEM), a known disrupter of the Nrf2:Keap1 interaction. DEM does not affect the ability of FAC1 to bind hKeap1 in our assay. These results suggest that hKeap1 regulates FAC1 in addition to its known role in control of Nrf2. Furthermore, the observed competition between FAC1 and Nrf2 for binding hKeap1 indicates that the interplay between these three proteins has important implications for neuronal response to oxidative stress.
    MeSH term(s) Actins/metabolism ; Amino Acid Motifs ; Animals ; Antigens, Nuclear ; Binding, Competitive/drug effects ; Cell Line ; Cytoplasm/metabolism ; DNA-Binding Proteins/metabolism ; DNA-Binding Proteins/pharmacology ; Fibroblasts ; Gene Expression Regulation ; Humans ; Intracellular Signaling Peptides and Proteins ; Kelch-Like ECH-Associated Protein 1 ; Maleates/pharmacology ; Mice ; NF-E2-Related Factor 2 ; Nerve Tissue Proteins/chemistry ; Nerve Tissue Proteins/genetics ; Nerve Tissue Proteins/metabolism ; Protein Binding ; Protein Structure, Tertiary ; Protein Transport ; Proteins/genetics ; Proteins/metabolism ; Trans-Activators/metabolism ; Trans-Activators/pharmacology ; Transcription Factors/chemistry ; Transcription Factors/genetics ; Transcription Factors/metabolism ; Two-Hybrid System Techniques
    Chemical Substances Actins ; Antigens, Nuclear ; DNA-Binding Proteins ; Intracellular Signaling Peptides and Proteins ; KEAP1 protein, human ; Kelch-Like ECH-Associated Protein 1 ; Maleates ; NF-E2-Related Factor 2 ; NFE2L2 protein, human ; Nerve Tissue Proteins ; Nfe2l2 protein, mouse ; Proteins ; Trans-Activators ; Transcription Factors ; fetal Alzheimer antigen ; diethyl maleate (G81WQB56OL)
    Language English
    Publishing date 2004-09-28
    Publishing country United States
    Document type Journal Article ; Research Support, U.S. Gov't, P.H.S.
    ZDB-ID 1108-3
    ISSN 1520-4995 ; 0006-2960
    ISSN (online) 1520-4995
    ISSN 0006-2960
    DOI 10.1021/bi0494166
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