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1.
EMBO J ; 36(8): 1100-1116, 2017 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-28320742

RESUMO

Macroautophagy allows for bulk degradation of cytosolic components in lysosomes. Overexpression of GFP/RFP-LC3/GABARAP is commonly used to monitor autophagosomes, a hallmark of autophagy, despite artifacts related to their overexpression. Here, we developed new sensors that detect endogenous LC3/GABARAP proteins at the autophagosome using an LC3-interacting region (LIR) and a short hydrophobic domain (HyD). Among HyD-LIR-GFP sensors harboring LIR motifs of 34 known LC3-binding proteins, HyD-LIR(TP)-GFP using the LIR motif from TP53INP2 allowed detection of all LC3/GABARAPs-positive autophagosomes. However, HyD-LIR(TP)-GFP preferentially localized to GABARAP/GABARAPL1-positive autophagosomes in a LIR-dependent manner. In contrast, HyD-LIR(Fy)-GFP using the LIR motif from FYCO1 specifically detected LC3A/B-positive autophagosomes. HyD-LIR(TP)-GFP and HyD-LIR(Fy)-GFP efficiently localized to autophagosomes in the presence of endogenous LC3/GABARAP levels and without affecting autophagic flux. Both sensors also efficiently localized to MitoTracker-positive damaged mitochondria upon mitophagy induction. HyD-LIR(TP)-GFP allowed live-imaging of dynamic autophagosomes upon autophagy induction. These novel autophagosome sensors can thus be widely used in autophagy research.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Autofagia , Proteínas do Citoesqueleto , Proteínas de Membrana , Proteínas Associadas aos Microtúbulos , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Motivos de Aminoácidos , Animais , Proteínas Reguladoras de Apoptose , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Células HeLa , Humanos , Interações Hidrofóbicas e Hidrofílicas , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Microscopia de Fluorescência , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Domínios Proteicos
2.
J Neurosci ; 36(33): 8641-52, 2016 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-27535911

RESUMO

UNLABELLED: MicroRNAs (miRNAs) are small, noncoding RNAs that posttranscriptionally regulate gene expression in many tissues. Although a number of brain-enriched miRNAs have been identified, only a few specific miRNAs have been revealed as critical regulators of synaptic plasticity, learning, and memory. miR-9-5p/3p are brain-enriched miRNAs known to regulate development and their changes have been implicated in several neurological disorders, yet their role in mature neurons in mice is largely unknown. Here, we report that inhibition of miR-9-3p, but not miR-9-5p, impaired hippocampal long-term potentiation (LTP) without affecting basal synaptic transmission. Moreover, inhibition of miR-9-3p in the hippocampus resulted in learning and memory deficits. Furthermore, miR-9-3p inhibition increased the expression of the LTP-related genes Dmd and SAP97, the expression levels of which are negatively correlated with LTP. These results suggest that miR-9-3p-mediated gene regulation plays important roles in synaptic plasticity and hippocampus-dependent memory. SIGNIFICANCE STATEMENT: Despite the abundant expression of the brain-specific microRNA miR-9-5p/3p in both proliferating and postmitotic neurons, most functional studies have focused on their role in neuronal development. Here, we examined the role of miR-9-5p/3p in adult brain and found that miR-9-3p, but not miR-9-5p, has a critical role in hippocampal synaptic plasticity and memory. Moreover, we identified in vivo binding targets of miR-9-3p that are involved in the regulation of long-term potentiation. Our study provides the very first evidence for the critical role of miR-9-3p in synaptic plasticity and memory in the adult mouse.


Assuntos
Hipocampo/metabolismo , MicroRNAs/metabolismo , Plasticidade Neuronal/fisiologia , Reconhecimento Psicológico/fisiologia , Animais , Condicionamento Psicológico/fisiologia , Proteína 1 Homóloga a Discs-Large , Distrofina/metabolismo , Comportamento Exploratório/fisiologia , Medo/fisiologia , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Guanilato Quinases/metabolismo , Células HEK293 , Hipocampo/citologia , Humanos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Plasticidade Neuronal/efeitos dos fármacos , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , Reconhecimento Psicológico/efeitos dos fármacos , Sinapsinas/genética , Sinapsinas/metabolismo , Transdução Genética
3.
Neurobiol Learn Mem ; 138: 31-38, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27344941

RESUMO

ADP-ribosylation factors (ARFs) are small guanosine triphosphatases of the Ras superfamily involved in membrane trafficking and regulation of the actin cytoskeleton. Aplysia Sec7 protein (ApSec7), a guanine nucleotide exchange factor for ARF1 and ARF6, induces neurite outgrowth and plays a key role in 5-hydroxyltryptamine-induced neurite growth and synaptic facilitation in Aplysia sensory-motor synapses. However, the specific role of ARF6 signaling on neurite outgrowth in Aplysia neurons has not been examined. In the present study, we cloned Aplysia ARF6 (ApARF6) and revealed that an overexpression of enhanced green fluorescent protein (EGFP)-fused constitutively active ApARF6 (ApARF6-Q67L-EGFP) could induce neurite outgrowth in Aplysia sensory neurons. Further, we observed that ApARF6-induced neurite outgrowth was inhibited by the co-expression of a Sec7 activity-deficient mutant of ApSec7 (ApSec7-E159K). The pleckstrin homology domain of ApSec7 may bind to active ApARF6 at the plasma membrane and prevent active ApARF6-induced functions, including intracellular vacuole formation in HEK293T cells. The results of the present study suggest that activation of ARF6 signaling could induce neurite outgrowth in Aplysia neurons and may be involved in downstream signaling of ApSec7-induced neurite outgrowth in Aplysia neurons.


Assuntos
Fatores de Ribosilação do ADP/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Neuritos/metabolismo , Crescimento Neuronal/fisiologia , Domínios de Homologia à Plecstrina/fisiologia , Células Receptoras Sensoriais/metabolismo , Animais , Aplysia , Células HEK293 , Humanos , Transdução de Sinais/fisiologia , Sinapses/metabolismo , Regulação para Cima
4.
J Neurochem ; 139(6): 1102-1112, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27787889

RESUMO

Cytohesin family proteins act as guanine nucleotide exchange factors (GEFs) for the ADP-ribosylation factor family of small GTP-binding proteins. Aplysia Sec7 (ApSec7), a member of the cytohesin family in Aplysia, plays key roles in neurite outgrowth in Aplysia neurons. Although ApSec7 has a conserved coiled-coil (CC) domain, its role was not clear. In this study, we found that the CC domain of ApSec7 and ARNO/cytohesin 2 are involved in homodimer formation, leading to efficient plasma membrane targeting of ApSec7 and ARNO/cytohesin 2 in HEK293T cells. Therefore, deletion of the CC domain of ApSec7 and ARNO/cytohesin 2 may result in a loss of dimerization and reduce plasma membrane localization. In addition, the CC domains of ApSec7 and ARNO/cytohesin 2 have partially or fully CRM1-dependent nuclear export signals, respectively. Taken together, our results suggest that the CC domain of cytohesin family proteins, including ApSec7 and ARNO/cytohesin 2, has dual roles in intracellular targeting: increased plasma membrane targeting through homodimer formation and nuclear exclusion through either a CRM1-dependent or a CRM1-independent pathway.


Assuntos
Transporte Ativo do Núcleo Celular/fisiologia , Fatores de Troca do Nucleotídeo Guanina/química , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Neurônios/metabolismo , Multimerização Proteica/fisiologia , Sequência de Aminoácidos , Animais , Aplysia , Células Cultivadas , Células HEK293 , Humanos , Ligação Proteica/fisiologia
5.
J Biol Chem ; 289(37): 25797-811, 2014 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-25077971

RESUMO

Phosphodiesterases (PDEs) play key roles in cAMP compartmentalization, which is required for intracellular signaling processes, through specific subcellular targeting. Previously, we showed that the long and short forms of Aplysia PDE4 (ApPDE4), which are localized to the membranes of distinct subcellular organelles, play key roles in 5-hydroxytryptamine-induced synaptic facilitation in Aplysia sensory and motor synapses. However, the molecular mechanism of the isoform-specific distinct membrane targeting was not clear. In this study, we further investigated the molecular mechanism of the membrane targeting of the ApPDE4 long and short forms. We found that the membrane targeting of the long form was mediated by hydrophobic interactions, mainly via 16 amino acids at the N-terminal region, whereas the short form was targeted solely to the plasma membrane, mainly by nonspecific electrostatic interactions between their N termini and the negatively charged lipids such as the phosphatidylinositol polyphosphates PI4P and PI(4,5)P2, which are embedded in the inner leaflet of the plasma membrane. Moreover, oligomerization of the long or short form by interaction of their respective upstream conserved region domains, UCR1 and UCR2, enhanced their plasma membrane targeting. These results suggest that the long and short forms of ApPDE4 are distinctly targeted to intracellular membranes through their direct association with the membranes via hydrophobic and electrostatic interactions, respectively.


Assuntos
3',5'-AMP Cíclico Fosfodiesterases/metabolismo , Aplysia/enzimologia , Isoformas de Proteínas/metabolismo , Sinapses/metabolismo , 3',5'-AMP Cíclico Fosfodiesterases/genética , Sequência de Aminoácidos , Animais , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4 , Membranas Intracelulares/efeitos dos fármacos , Isoformas de Proteínas/genética , Multimerização Proteica/genética , Serotonina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Sinapses/genética
6.
Proc Natl Acad Sci U S A ; 109(38): 15520-5, 2012 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-22949683

RESUMO

The consolidation of long-term memory for sensitization and synaptic facilitation in Aplysia requires synthesis of new mRNA including the immediate early gene Aplysia CCAAT enhancer-binding protein (ApC/EBP). After the rapid induction of ApC/EBP expression in response to repeated treatments of 5-hydroxytryptamine (5-HT), ApC/EBP mRNA is temporarily expressed in sensory neurons of sensory-to-motor synapses. However, the molecular mechanism underlying the rapid degradation of ApC/EBP transcript is not known. Here, we cloned an AU-rich element (ARE)-binding protein, ApAUF1, which functions as a destabilizing factor for ApC/EBP mRNA. ApAUF1 was found to bind to the 3' UTR of ApC/EBP mRNA that contains AREs and subsequently reduces the expression of ApC/EBP 3' UTR-containing reporter genes. Moreover, overexpression of ApAUF1 inhibited the induction of ApC/EBP mRNA in sensory neurons and also impaired long-term facilitation of sensory-to-motor synapses by repetitive 5-HT treatments. These results provide evidence for a critical role of the posttranscriptional modification of ApC/EBP mRNA during the consolidation of synaptic plasticity.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Regulação da Expressão Gênica , Ribonucleoproteínas Nucleares Heterogêneas Grupo D/metabolismo , Transmissão Sináptica , Regiões 3' não Traduzidas , Animais , Aplysia , Clonagem Molecular , Genes Reporter , Células HEK293 , Ribonucleoproteína Nuclear Heterogênea D0 , Humanos , Hibridização In Situ , Modelos Biológicos , Modelos Genéticos , Plasticidade Neuronal , Processamento Pós-Transcricional do RNA , RNA Mensageiro/metabolismo
7.
Proc Natl Acad Sci U S A ; 109(35): 14200-5, 2012 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-22893682

RESUMO

The memory reconsolidation hypothesis suggests that a memory trace becomes labile after retrieval and needs to be reconsolidated before it can be stabilized. However, it is unclear from earlier studies whether the same synapses involved in encoding the memory trace are those that are destabilized and restabilized after the synaptic reactivation that accompanies memory retrieval, or whether new and different synapses are recruited. To address this issue, we studied a simple nonassociative form of memory, long-term sensitization of the gill- and siphon-withdrawal reflex in Aplysia, and its cellular analog, long-term facilitation at the sensory-to-motor neuron synapse. We found that after memory retrieval, behavioral long-term sensitization in Aplysia becomes labile via ubiquitin/proteasome-dependent protein degradation and is reconsolidated by means of de novo protein synthesis. In parallel, we found that on the cellular level, long-term facilitation at the sensory-to-motor neuron synapse that mediates long-term sensitization is also destabilized by protein degradation and is restabilized by protein synthesis after synaptic reactivation, a procedure that parallels memory retrieval or retraining evident on the behavioral level. These results provide direct evidence that the same synapses that store the long-term memory trace encoded by changes in the strength of synaptic connections critical for sensitization are disrupted and reconstructed after signal retrieval.


Assuntos
Memória/fisiologia , Neurônios Motores/fisiologia , Células Receptoras Sensoriais/fisiologia , Sinapses/fisiologia , Animais , Aplysia , Comportamento Animal/fisiologia , Células Cultivadas , Técnicas de Cocultura , Eletrochoque , Potenciais Pós-Sinápticos Excitadores/fisiologia , Medo/fisiologia , Brânquias/inervação , Memória/efeitos dos fármacos , Modelos Animais , Neurônios Motores/citologia , Proteínas do Tecido Nervoso/biossíntese , Plasticidade Neuronal/efeitos dos fármacos , Plasticidade Neuronal/fisiologia , Reflexo/fisiologia , Células Receptoras Sensoriais/citologia , Serotonina/farmacologia , Agonistas do Receptor de Serotonina/farmacologia
8.
Exp Cell Res ; 319(13): 1998-2005, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-23742895

RESUMO

Tar-DNA binding protein of 43kDa (TDP-43) has been characterized as a major component of protein aggregates in brains with neurodegenerative diseases such as frontotemporal lobar degeneration (FTLD) and amyotrophic lateral sclerosis (ALS). However, physiological roles of TDP-43 and early cellular pathogenic effects caused by disease associated mutations in differentiated neurons are still largely unknown. Here, we investigated the physiological roles of TDP-43 and the effects of missense mutations associated with diseases in differentiated cortical neurons. The reduction of TDP-43 by siRNA increased abnormal neurites and decreased cell viability. ALS/FTLD-associated missense mutant proteins (A315T, Q331K, and M337V) were partially mislocalized to the cytosol and neurites when compared to wild-type and showed abnormal neurites similar to those observed in cases of loss of TDP-43. Interestingly, cytosolic expression of wild-type TDP-43 with mutated nuclear localization signals also induced abnormal neurtie morphology and reduction of cell viability. However, there was no significant difference in the effects of cytosolic expression in neuronal morphology and cell toxicity between wild-type and missense mutant proteins. Thus, our results suggest that mislocalization of missense mutant TDP-43 may contribute to loss of TDP-43 function and affect neuronal morphology, probably via dominant negative action before severe neurodegeneration in differentiated cortical neurons.


Assuntos
Proteínas de Ligação a DNA/fisiologia , Neuritos/fisiologia , Neurônios/fisiologia , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Animais , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Forma Celular/genética , Sobrevivência Celular/genética , Células Cultivadas , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Embrião de Mamíferos , Degeneração Lobar Frontotemporal/genética , Degeneração Lobar Frontotemporal/patologia , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos ICR , Mutação de Sentido Incorreto/fisiologia , Degeneração Neural/genética , Degeneração Neural/metabolismo , Neuritos/metabolismo , Neuritos/patologia , Neurônios/metabolismo , Neurônios/patologia , Transporte Proteico/genética
9.
Stem Cells Transl Med ; 13(7): 637-647, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38838263

RESUMO

Extracellular vesicles, particularly exosomes, have emerged as promising drug delivery systems owing to their unique advantages, such as biocompatibility, immune tolerability, and target specificity. Various engineering strategies have been implemented to harness these innate qualities, with a focus on enhancing the pharmacokinetic and pharmacodynamic properties of exosomes via payload loading and surface engineering for active targeting. This concise review outlines the challenges in the development of exosomes as drug carriers and offers insights into strategies for their effective clinical translation. We also highlight preclinical studies that have successfully employed anti-inflammatory exosomes and suggest future directions for exosome therapeutics. These advancements underscore the potential for integrating exosome-based therapies into clinical practice, heralding promise for future medical interventions.


Assuntos
Sistemas de Liberação de Medicamentos , Exossomos , Exossomos/metabolismo , Humanos , Sistemas de Liberação de Medicamentos/métodos , Animais , Portadores de Fármacos/química
10.
J Neurosci ; 32(46): 16296-305, 2012 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-23152613

RESUMO

Long-term facilitation in Aplysia is accompanied by the growth of new synaptic connections between the sensory and motor neurons of the gill-withdrawal reflex. One of the initial steps leading to the growth of these synapses is the internalization, induced by 5-HT, of the transmembrane isoform of Aplysia cell-adhesion molecule (TM-apCAM) from the plasma membrane of sensory neurons (Bailey et al., 1992). However, the mechanisms that govern the internalization of TM-apCAM and how this internalization is coupled to the molecular events that initiate the structural changes are not fully understood. Here, we report that the synthesis of membrane phosphatidylinositol 4,5-bisphosphate [PI(4,5)P(2)], which is known to be mediated by a signaling cascade through Aplysia Sec7 protein (ApSec7) and phosphatidylinositol-4-phosphate 5-kinase type I α (PIP5KIα) is required for both the internalization of TM-apCAM and the initiation of synaptic growth during 5-HT-induced long-term facilitation. Pharmacological blockade of PI(4,5)P(2) synthesis by the application of the inhibitor phenylarsine oxide blocked the internalization of apCAM. Furthermore, perturbation of the endogenous activation of ApSec7 and its downstream target PIP5KIα also blocked 5-HT-mediated internalization of TM-apCAM and synaptic growth. Finally, long-term facilitation was specifically impaired by blocking the ApSec7 signaling pathway at sensory-to-motor neuron synapses. These data indicate that the ApSec7/PIP5KIα signaling pathway is actively recruited during learning-related 5-HT signaling and acts as a key regulator of apCAM internalization associated with the formation of new synaptic connections during long-term facilitation.


Assuntos
Aplysia/fisiologia , Vias Biossintéticas/fisiologia , Moléculas de Adesão Celular/fisiologia , Aprendizagem/fisiologia , Fosfatidilinositol 4,5-Difosfato/biossíntese , Fosfatidilinositol 4,5-Difosfato/fisiologia , Sinapses/fisiologia , 1-Fosfatidilinositol 4-Quinase/metabolismo , Sequência de Aminoácidos , Animais , Membrana Celular/fisiologia , Clonagem Molecular , Técnicas de Cocultura , Fatores de Troca do Nucleotídeo Guanina/fisiologia , Imuno-Histoquímica , Potenciação de Longa Duração/fisiologia , Microinjeções , Dados de Sequência Molecular , Mutação/genética , Mutação/fisiologia , Neuritos/fisiologia , Técnicas de Patch-Clamp , Reação em Cadeia da Polimerase em Tempo Real , Células Receptoras Sensoriais/fisiologia , Serotonina/farmacologia , Transdução de Sinais/fisiologia
11.
Healthcare (Basel) ; 11(15)2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37570374

RESUMO

This study aims to predict the characteristics of the exercise healthcare industry in the post-pandemic era by comparing the periods before and after the coronavirus disease 2019 outbreak through big data analysis. TEXTOM, the Korean big data collection and analysis solution, was used for data collection. The pre-pandemic period was defined as 1 January 2018-31 December 2019 and the pandemic period as 1 January 2020-31 December 2021. The keywords for data collection were "exercise + healthcare + industry". Text mining and social network analysis were conducted to determine the overall characteristics of the Korean exercise healthcare industry. We identified 30 terms that appeared most frequently on social media. Four common (smart management, future technology, fitness, and research) and six different clusters (sports education, exercise leader, rehabilitation, services, business, and COVID-19) were obtained for the pre-pandemic and pandemic periods. Smart management, future technology, fitness, and research are still important values across both periods. The results provide meaningful data and offer valuable insights to explore the changing trends in exercise healthcare.

12.
Artigo em Inglês | MEDLINE | ID: mdl-36767125

RESUMO

Individuals with disabilities who engage in regular physical activity reduce their risk of diseases such as obesity and heart disease, as well as other risk factors; relieve tense emotions, and improve their quality of life via interaction with others. Despite these advantages, only one out of every four Koreans with a disability engages in physical activity. Grit is the ability to maintain interest and effort towards a goal in the face of adversity and failure. Grit can act as an important factor in increasing the psychological level of individuals with disabilities. We investigated the relationship between basic psychological needs, grit, and the quality of life of disabled individuals to determine if physical activities can improve their quality of life. Our dataset included 296 disabled individuals registered with the Korean Ministry of Health and Welfare. Using structural equation modelling, the direct and indirect effects of grit, quality of life, and psychological needs satisfaction such as competence, relatedness, and autonomy were examined. We found that competence positively affects consistency of interests (ß = 0.150, t = 1.854), relatedness positively affects consistency of interests (ß = 0.354, t = 4.409), and autonomy has no statistically significant effects (ß = 0.101, t = 1.086). Second, competence positively affects perseverance of effort (ß = 0.249, t = 3.206), autonomy negatively affects perseverance of effort (ß = -0.269, t = -2.880), and relatedness has no statistically significant effects (ß = -0.017, t = -0.249). Third, autonomy positively affects quality of life (ß = 0.214, t = 2.349) while competence and relatedness had no statistically significant effects (ß = -0.018, t = -0.208; ß = 0.096, t = 1.288). Fourth, consistency of interests positively affects quality of life (ß = 0.312, t = 4.191) while perseverance of effort had no statistically significant effects (ß = -0.094, t = -1.480). Fifth, competence was found to have positive indirect effects on quality of life through grit. This study underscores the importance of addressing these three basic psychological needs and elements of grit when designing future quality of life interventions for disabled individuals.


Assuntos
Pessoas com Deficiência , Qualidade de Vida , Humanos , Motivação , Satisfação Pessoal , Emoções
13.
Autophagy ; 19(5): 1424-1443, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36250672

RESUMO

ABBREVIATIONS: A:C autophagic membrane:cytosol; ALS amyotrophic lateral sclerosis; ATG4 autophagy related 4; Atg8 autophagy related 8; BafA1 bafilomycin A1; BNIP3L/Nix BCL2 interacting protein 3 like; CALCOCO2/NDP52 calcium binding and coiled-coil domain 2; EBSS Earle's balanced salt solution; GABARAP GABA type A receptor-associated protein; GST glutathione S transferase; HKO hexa knockout; Kd dissociation constant; LIR LC3-interacting region; MAP1LC3/LC3 microtubule associated protein 1 light chain 3; NLS nuclear localization signal/sequence; PE phosphatidylethanolamine; SpHfl1 Schizosaccharomyces pombeorganic solute transmembrane transporter; SQSTM1/p62 SQSTM1/p62; TARDBP/TDP-43 TAR DNA binding protein; TKO triple knockout.


Assuntos
Autofagia , Proteínas de Membrana , Animais , Família da Proteína 8 Relacionada à Autofagia/metabolismo , Proteínas de Membrana/metabolismo , Proteína Sequestossoma-1/metabolismo , Autofagia/genética , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Mamíferos/metabolismo
14.
Biochem Biophys Res Commun ; 421(3): 544-9, 2012 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-22521643

RESUMO

Endosomal sorting complexes required for transport (ESCRTs) regulate a key sorting step of protein trafficking between endosomal compartments in lysosomal degradation. Interestingly, mutations in charged multivesicular body protein 2B (CHMP2B), which is a core subunit of ESCRT-III, have been identified in some neurodegenerative diseases. However, the cellular pathogenesis resulting from CHMP2B missense mutations is unclear. Furthermore, little is known about their functional analysis in post-mitotic neurons. In order to examine their cellular pathogenesis, we analyzed their effects in the endo-lysosomal pathway in post-mitotic neurons. Interestingly, of the missense mutant proteins, CHMP2B(T104N) mostly accumulated in the Rab5- and Rab7-positive endosomes and caused delayed degradation of EGFR as compared to CHMP2B(WT). Furthermore, CHMP2B(T104N) showed less association with Vps4 ATPase and was avidly associated with Snf7-2, a core component of ESCRT-III, suggesting that it may cause defects in the process of dissociation from ESCRT. Of the missense variants, CHMP2B(T104N) caused prominent accumulation of autophagosomes. However, neuronal cell survival was not dramatically affected by expression of CHMP2B(T104N). These findings suggested that, from among the various missense mutants, CHMP2B(T104N) was associated with relatively mild cellular pathogenesis in post-mitotic neurons. This study provided a better understanding of the cellular pathogenesis of neurodegenerative diseases associated with various missense mutations of CHMP2B as well as endocytic defects.


Assuntos
Autofagia , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Lisossomos/metabolismo , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/metabolismo , Neurônios/metabolismo , ATPases Associadas a Diversas Atividades Celulares , Adenosina Trifosfatases/metabolismo , Sobrevivência Celular , Células Cultivadas , Receptores ErbB/metabolismo , Humanos , Mitose , Mutação de Sentido Incorreto , Proteólise
15.
Proc Natl Acad Sci U S A ; 106(34): 14634-9, 2009 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-19706550

RESUMO

Serotonin (5-HT) plays a critical role in modulating synaptic plasticity in the marine mollusc Aplysia and in the mammalian nervous system. In Aplysia sensory neurons, 5-HT can activate several signal cascades, including PKA and PKC, presumably via distinct types of G protein-coupled receptors. However, the molecular identities of these receptors have not yet been identified. We here report the cloning and functional characterization of a 5-HT receptor that is positively coupled to adenylyl cyclase in Aplysia neurons. The cloned receptor, 5-HT(apAC1), stimulates the production of cAMP in HEK293T cells and in Xenopus oocytes. Moreover, the knockdown of 5-HT(apAC1) expression by RNA interference blocked 5-HT-induced cAMP production in Aplysia sensory neurons and blocked synaptic facilitation in nondepressed or partially depressed sensory-to-motor neuron synapses. These data implicate 5-HT(apAC1) as a major modulator of learning related synaptic facilitation in the direct sensory to motor neuron pathway of the gill withdrawal reflex.


Assuntos
Adenilil Ciclases/metabolismo , Aplysia/fisiologia , Pareamento Cromossômico/fisiologia , Aprendizagem/fisiologia , Receptores de Serotonina/fisiologia , Adenilil Ciclases/genética , Sequência de Aminoácidos , Animais , Aplysia/citologia , Aplysia/genética , Western Blotting , Linhagem Celular , Células Cultivadas , Clonagem Molecular , AMP Cíclico/metabolismo , Feminino , Humanos , Hibridização In Situ , Potenciais da Membrana , Dados de Sequência Molecular , Oócitos/metabolismo , Oócitos/fisiologia , Filogenia , Receptores de Serotonina/classificação , Receptores de Serotonina/genética , Células Receptoras Sensoriais/citologia , Células Receptoras Sensoriais/metabolismo , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Serotonina/farmacologia , Transfecção , Xenopus laevis
16.
Proc Natl Acad Sci U S A ; 105(47): 18602-7, 2008 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-19017802

RESUMO

The marine mollusk Aplysia is a useful model organism for studying the cellular bases of behavior and plasticity. However, molecular studies of Aplysia have been limited by the lack of genomic information. Recently, a large scale characterization of neuronal transcripts was performed in A. californica. Here, we report the analysis of a parallel set of neuronal transcripts from a closely related species A. kurodai found in the northwestern Pacific. We collected 4,859 nonredundant sequences from the nervous system tissue of A. kurodai. By performing microarray and real-time PCR analyses, we found that ApC/EBP, matrilin, antistasin, and eIF3e clones were significantly up-regulated and a BAT1 homologous clone was significantly down-regulated by 5-HT treatment. Among these, we further demonstrated that the Ap-eIF3e plays a key role in 5-HT-induced long-term facilitation (LTF) as a positive regulator.


Assuntos
Aplysia/fisiologia , Plasticidade Neuronal , RNA Mensageiro/genética , Animais , Aplysia/metabolismo , Sequência de Bases , Primers do DNA , Etiquetas de Sequências Expressas , Potenciação de Longa Duração/efeitos dos fármacos , Reação em Cadeia da Polimerase , Serotonina/farmacologia
17.
Learn Mem ; 17(9): 469-79, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20813835

RESUMO

Phosphodiesterases (PDEs) are known to play a key role in the compartmentalization of cAMP signaling; however, the molecular mechanisms underlying intracellular localization of different PDE isoforms are not understood. In this study, we have found that each of the supershort, short, and long forms of apPDE4 showed distinct localization in the cytoplasm, plasma membrane, and both plasma membrane and presynaptic terminals, respectively. The N-terminal 20 amino acids of the long form of apPDE4 were involved in presynaptic terminal targeting by binding to several lipids. In addition, the N terminus of the short form of apPDE4 bound to several lipids including phosphoinositols, thereby targeting the plasma membrane. Overexpression of the long and the short forms, but not the supershort form attenuated 5-HT-induced membrane hyperexcitability. Finally, the knockdown of apPDE4s in sensory neurons impaired both short-term and long-term facilitation. Thus, these results suggest that apPDE4s can participate in the regulation of cAMP signaling through specific subcellular localization by means of lipid binding activities.


Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/química , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Potenciais da Membrana/genética , Células Receptoras Sensoriais/fisiologia , Sequência de Aminoácidos , Animais , Aplysia , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Células Cultivadas , AMP Cíclico/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/genética , Cisteína/metabolismo , Gânglios dos Invertebrados/citologia , Proteínas de Fluorescência Verde/genética , Humanos , Imunoprecipitação/métodos , Lipídeos de Membrana/metabolismo , Mutação/genética , Terminações Pré-Sinápticas/metabolismo , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Estrutura Terciária de Proteína , Interferência de RNA/fisiologia , Células Receptoras Sensoriais/efeitos dos fármacos , Serotonina/farmacologia , Frações Subcelulares/efeitos dos fármacos , Frações Subcelulares/metabolismo , Sinaptofisina/metabolismo , Transfecção/métodos
18.
BMB Rep ; 54(2): 118-123, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33298241

RESUMO

The bacterial effector protein RavZ from a pathogen can impair autophagy in the host by delipidating the mammalian autophagy- related gene 8 (mATG8)-phosphatidylethanolamine (PE) on autophagic membranes. In RavZ, the membrane-targeting (MT) domain is an essential function. However, the molecular mechanism of this domain in regulating the intracellular localization of RavZ in cells is unclear. In this study, we found that the fusion of the green fluorescent protein (GFP) to the MT domain of RavZ (GFP-MT) resulted in localization primarily to the cytosol and nucleus, whereas the GFP-fused duplicated-MT domain (GFP-2xMT) localized to Rab5- or Rab7-positive endosomes. Similarly, GFP fusion to the catalytic domain (CA) of RavZ (GFP-CA) resulted in localization primarily to the cytosol and nucleus, even in autophagy-induced cells. However, by adding the MT domain to GFP-CA (GFP-CA-MT), the cooperation of MT and CA led to localization on the Rab5-positive endosomal membranes in a wortmannin-sensitive manner under nutrient-rich conditions, and to autophagic membranes in autophagy-induced cells. In autophagic membranes, GFP-CA-MT delipidated overexpressed or endogenous mATG8-PE. Furthermore, GFP-CAΔα3-MT, an α3 helix deletion within the CA domain, failed to localize to the endosomal or autophagic membranes and could not delipidate overexpressed mATG8-PE. Thus, the CA or MT domain alone is insufficient for stable membrane localization in cells, but the cooperation of MT and CA leads to localization to the endosomal and autophagic membranes. In autophagic membranes, the CA domain can delipidate mATG8-PE without requiring substrate recognition mediated by LC3-interacting region (LIR) motifs. [BMB Reports 2021; 54(2): 118-123].


Assuntos
Proteínas Relacionadas à Autofagia/metabolismo , Endossomos/metabolismo , Membranas Intracelulares/metabolismo , Autofagia , Domínio Catalítico , Proteínas de Fluorescência Verde/metabolismo , Humanos
19.
J Neurosci ; 29(26): 8493-505, 2009 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-19571140

RESUMO

The cAMP cascade and vascular endothelial growth factor (VEGF) are critical modulators of depression. Here we have tested whether the antidepressive effect of the cAMP cascade is mediated by VEGF in the adult hippocampus. We used a conditional genetic system in which the Aplysia octopamine receptor (Ap oa(1)), a G(s)-coupled receptor, is transgenically expressed in the forebrain neurons of mice. Chronic activation of the heterologous Ap oa(1) by its natural ligand evoked antidepressant-like behaviors, accompanied by enhanced phosphorylation of cAMP response element-binding protein and transcription of VEGF in hippocampal dentate gyrus (DG) neurons. Selective knockdown of VEGF in these cells during the period of cAMP elevation inhibited the antidepressant-like behaviors. These findings reveal a molecular interaction between the cAMP cascade and VEGF expression, and the pronounced behavioral consequences of this interaction shed light on the mechanism underlying neuronal VEGF functions in antidepression.


Assuntos
AMP Cíclico/farmacologia , Giro Denteado/citologia , Depressão , Regulação da Expressão Gênica/efeitos dos fármacos , Neurônios/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Análise de Variância , Animais , Antidepressivos de Segunda Geração/farmacologia , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Bromodesoxiuridina/metabolismo , Proteína de Ligação a CREB/metabolismo , Linhagem Celular Transformada , Imunoprecipitação da Cromatina/métodos , AMP Cíclico/metabolismo , Depressão/genética , Depressão/patologia , Modelos Animais de Doenças , Ensaio de Desvio de Mobilidade Eletroforética/métodos , Comportamento Exploratório , Comportamento Alimentar , Fluoxetina/farmacologia , Preferências Alimentares/efeitos dos fármacos , Preferências Alimentares/fisiologia , Regulação da Expressão Gênica/fisiologia , Humanos , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neurogênese/efeitos dos fármacos , Neurogênese/genética , Neurônios/efeitos dos fármacos , Octopamina/farmacologia , RNA Interferente Pequeno/genética , Receptores de Amina Biogênica/genética , Transfecção/métodos , Fator A de Crescimento do Endotélio Vascular/genética , Vasoconstritores/farmacologia
20.
Artigo em Inglês | MEDLINE | ID: mdl-32664696

RESUMO

Although participating in regular physical activity has many benefits, female Korean college students tend to have much lower participation rates than their male counterparts. An effective means of increasing physical activity among female college students is sport participation. The purpose of this study is to incorporate three types of psychological needs from self-determination theory as precursor background variables into the theory of planned behavior to predict sport participation among female Korean college students. Our dataset consisted of 494 female undergraduate students attending Kyung Hee University in South Korea. Using structural equation modeling, the direct and indirect effects of attitude, subjective norm, perceived behavioral control, and psychological needs satisfaction such as competency, relatedness, and autonomy were examined. Although attitude towards and perceived behavioral control over sport participation were significantly associated with intention in all three models, subjective norm was not significantly associated with intention in any model. Satisfaction of the psychological needs for competency, relatedness, and autonomy had positive indirect effects on sport participation. This study underscores the importance of addressing the satisfaction of these three basic psychological needs when designing future sport promotion interventions for female college students.


Assuntos
Intenção , Esportes/psicologia , Estudantes/psicologia , Povo Asiático , Atitude Frente a Saúde/etnologia , Feminino , Humanos , Masculino , Modelos Psicológicos , República da Coreia , Inquéritos e Questionários , Universidades
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