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1.
Biosci Biotechnol Biochem ; 85(6): 1441-1447, 2021 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-33749776

RESUMO

Glycogen synthesis in bacteria is mainly organized by the products of glgB, glgC, and glgA genes comprising the widely known glg operon. On the genome of extremely halophilic archaeon Haloarcula japonica, there was a gene cluster analogous to the bacterial glg operon. In this study, we focused on a GlgC homolog of Ha. japonica, and its recombinant enzyme was prepared and characterized. The enzyme showed highest activity toward GTP and glucose-1-phosphate as substrates in the presence of 2.6 m KCl and predicted to be work as "GDP-glucose pyrophosphorylase" in Ha. japonica.


Assuntos
Proteínas Arqueais/genética , Haloarcula/genética , Homologia de Sequência do Ácido Nucleico , Proteínas Arqueais/metabolismo , Glicogênio/biossíntese , Guanosina Trifosfato/metabolismo , Haloarcula/metabolismo , Óperon/genética
2.
Proc Natl Acad Sci U S A ; 115(14): 3646-3651, 2018 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-29555767

RESUMO

Daily rhythms of behaviors and physiologies are generated by the circadian clock, which is composed of clock genes and the encoded proteins forming transcriptional/translational feedback loops (TTFLs). The circadian clock is a self-sustained oscillator and flexibly responds to various time cues to synchronize with environmental 24-h cycles. However, the key molecule that transmits cellular stress to the circadian clockwork is unknown. Here we identified apoptosis signal-regulating kinase (ASK), a member of the MAPKKK family, as an essential mediator determining the circadian period and phase of cultured cells in response to osmotic changes of the medium. The physiological impact of ASK signaling was demonstrated by a response of the clock to changes in intracellular redox states. Intriguingly, the TTFLs drive rhythmic expression of Ask genes, indicating ASK-mediated association of the TTFLs with intracellular redox. In behavioral analysis, Ask1, Ask2, and Ask3 triple-KO mice exhibited compromised light responses of the circadian period and phase in their activity rhythms. LC-MS/MS-based proteomic analysis identified a series of ASK-dependent and osmotic stress-responsive phosphorylations of proteins, among which CLOCK, a key component of the molecular clockwork, was phosphorylated at Thr843 or Ser845 in the carboxyl-terminal region. These findings reveal the ASK-dependent stress response as an underlying mechanism of circadian clock flexibility.


Assuntos
Relógios Circadianos/fisiologia , MAP Quinase Quinase Quinase 5/fisiologia , MAP Quinase Quinase Quinases/fisiologia , Pressão Osmótica , Animais , Comportamento Animal , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oxirredução , Fosforilação , Processamento de Proteína Pós-Traducional , Proteômica , Transdução de Sinais
3.
Sensors (Basel) ; 19(10)2019 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-31137539

RESUMO

The gas pipeline requires regular inspection since the leakage brings damage to the stable gas supply. Compared to current detection methods such as destructive inspection, using pipeline robots has advantages including low cost and high efficiency. However, they have a limited inspection range in the complex pipe owing to restrictions by the cable friction or wireless signal attenuation. In our former study, to extend the inspection range, we proposed a robot chain system based on wireless relay communication (WRC). However, some drawbacks still remain such as imprecision of evaluation based on received signal strength indication (RSSI), large data error ratio, and loss of signals. In this article, we thus propose a new approach based on visible light relay communication (VLRC) and illuminance assessment. This method enables robots to communicate by the 'light signal relay', which has advantages in good communication quality, less attenuation, and high precision in the pipe. To ensure the stability of VLRC, the illuminance-based evaluation method is adopted due to higher stability than the wireless-based approach. As a preliminary evaluation, several tests about signal waveform, communication quality, and coordinated movement were conducted. The results indicate that the proposed system can extend the inspection range with less data error ratio and more stable communication.

4.
J Org Chem ; 83(24): 14853-14860, 2018 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-30336031

RESUMO

The hypervalent iodine/HF reagent consisting of PhIO and HF·py was found to be effective for fluorination of functionalized aromatic olefins bearing synthetically important carbonyl and hydroxyl groups. Fluorination of 1,3-diphenyl-2-propen-1-one with PhIO/HF·py reagent in CH2Cl2 at room temperature gave 3,3-difluoro-1,2-diphenyl-1-propanone in high yield. Other α-aryl-α,ß-unsaturated ketones underwent the fluorination to yield aryl 2,2-difluoroethyl ketone derivatives in good to high yields. Catalytic fluorination of α-aryl-α,ß-unsaturated ketones using a p-TolI/HF·py/mCPBA reagent system also worked well. Moreover, the fluorination of cinnamyl alcohol derivatives by PhIO/HF·py reagent proceeded smoothly to afford 2-aryl-3,3-difluoro-1-propanols in moderate yields.

5.
Sci Rep ; 8(1): 6897, 2018 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-29720646

RESUMO

The acquisition of environmental osmolality tolerance traits in individuals and gametes is an important event in the evolution and diversification of organisms. Although teleost fish exhibit considerable intra- and interspecific variation in salinity tolerance, the genetic mechanisms underlying this trait remain unclear. Oryzias celebensis survives in sea and fresh water during both the embryonic and adult stages, whereas its close relative Oryzias woworae cannot survive in sea water at either stage. A linkage analysis using backcross progeny identified a single locus responsible for adult hyperosmotic tolerance on a fused chromosome that corresponds to O. latipes linkage groups (LGs) 6 and 23. Conversely, O. woworae eggs fertilised with O. celebensis sperm died in sea water at the cleavage stages, whereas O. celebensis eggs fertilised with O. woworae sperm developed normally, demonstrating that maternal factor(s) from O. celebensis are responsible for hyperosmotic tolerance during early development. A further linkage analysis using backcrossed females revealed a discrete single locus relating to the maternal hyperosmotic tolerance factor in a fused chromosomal region homologous to O. latipes LGs 17 and 19. These results indicate that a maternal factor governs embryonic hyperosmotic tolerance and maps to a locus distinct from that associated with adult hyperosmotic tolerance.


Assuntos
Adaptação Biológica , Oryzias/fisiologia , Pressão Osmótica , Locos de Características Quantitativas , Característica Quantitativa Herdável , Animais , Mapeamento Cromossômico , Cromossomos , Estudos de Associação Genética , Ligação Genética , Escore Lod , Oryzias/classificação
6.
Virology ; 450-451: 98-105, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24503071

RESUMO

Human herpesvirus 6 (HHV-6), which replicates abundantly in T cells, belongs to the Roseolovirus genus within the betaherpesvirus subfamily. Members of the Roseolovirus genus encode seven unique genes, U20, U21, U23, U24, U24A, U26, and U100. The present study focused on one of these, U23, by analyzing the characteristics of its gene product in HHV-6A-infected cells. The results indicated that the U23 protein was expressed at the late phase of infection as a glycoprotein, but was not incorporated into virions, and mostly stayed within the trans Golgi network (TGN) in HHV-6A-infected cells. Furthermore, analysis using a U23-defective mutant virus showed that the gene is nonessential for viral replication in vitro.


Assuntos
Glicoproteínas/metabolismo , Herpesvirus Humano 6/metabolismo , Infecções por Roseolovirus/virologia , Proteínas Virais/metabolismo , Linhagem Celular , Regulação Viral da Expressão Gênica , Glicoproteínas/genética , Herpesvirus Humano 6/genética , Herpesvirus Humano 6/crescimento & desenvolvimento , Humanos , Transporte Proteico , Infecções por Roseolovirus/metabolismo , Proteínas Virais/genética , Rede trans-Golgi/metabolismo , Rede trans-Golgi/virologia
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