• 제목/요약/키워드: ATPase subunits

검색결과 22건 처리시간 0.03초

Immunochemical Studies for the Characterization of Purified $(Na^+,\;K^+)-ATPase$ and Its Subunits with a Special Reference of Their Effect on Monovalent Cation Transport in Reconstituted $(Na^+,\;K^+)-ATPase$ Vesicles

  • Rhee, H.M.;Hokin, L.E.
    • 대한약리학회지
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    • 제26권1호
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    • pp.35-49
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    • 1990
  • A highly purified $(Na^+,\;K^+)-ATPase$ from the rectal gland of Squalus acanthias and from the electric organ of Electrophorus electricus has been used to raise antibodies in rabbits. The 97,000 dalton catalytic subunit and glycoprotein derived from the rectal gland of spiny shark were also used as antigens. The two $(Na^+,\;K^+)-ATPase$ holoenzymes and the two shark subunits were antigenic. In Ouchterlony double diffusion experiments, these antibodies formed precipitation bands with their antigens. Antibodies prepared against the two subunits of shark holoenzyme also formed precipitation bands with their antigens and shark holoenzyme, but not with eel holoenzyme. These observations are in good agreement with inhibitory effect of these antibodies on the catalytic activity of $(Na^+,\;K^+)-ATPase$ both from the shark and the eel, since there is very little cross-reaction between the shark anticatalytic subunit antibodies and the eel holoenzyme. The maximum antibodies titer of the anticatalytic subunit antibodies is found to be 6 weeks after the initial single exposure to this antigen. Multiple injections of the antigen increased the antibody titer. However, the time required to produce the maximum antibody titer was approximately the same. These antibodies also inhibit catalytic activity of $(Na^+,\;K^+)-ATPase$ vesicles reconstituted by a slow dialysis of cholate after solubilization of the enzyme in a presonicated mixture of cholate and phospholipid. In these reconstituted $(Na^+,\;K^+)-ATPase$ vesicles, effects of these antibodies on the fluxes of $Na^+$, $Rb^+$, and $K^+$ were investigated. Control or preimmune serum had no effect on the influx of $^{22}Na^+$ or the efflux of $^{86}Rb^+$. Immunized sera against the shark $(Na^+,\;K^+)-ATPase$ holoenzyme, its glycoprotein or catalytic subunit did inhibit the influx of $^{22}Na^+$ and the efflux of $^{86}Rb^+$. It was also demonstrated that these antibodies inhibit the coupled counter-transport of $Na^+$ and $K^+$ as studied by means of dual labeling experiments. However, this inhibitory effect of the antibodies on transport of ions in the $(Na^+,\;K^+)-ATPase$ vesicles is manifested only on the portion of energy and temperature dependent alkali metal fluxes, not on the portion of ATP and ouabain insensitive ion movement. Simultaneous determination of effects of the antibodies on ion fluxes and vesicular catalytic activity indicates that an inhibition of active ion transport in reconstituted $(Na^+,\;K^+)-ATPase$ vesicles appears to be due to the inhibitory action of the antibodies on the enzymatic activity of $(Na^+,\;K^+)-ATPase$ molecules incorporated in the vesicles. These findings that the inhibitory effects of the antibodies specific to $(Na^+,\;K^+)-ATPase$ or to its subunits on ATP and temperature sensitive monovalent cation transport in parallel with the inhibitory effect of vesicular catalytic activity by these antibodies provide direct evidence that $(Na^+,\;K^+)-ATPase$ is the molecular machinery of active cation transport in this reconstituted $(Na^+,\;K^+)-ATPase$ vesicular system.

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CHIP promotes the degradation of mutant SOD1 by reducing its interaction with VCP and S6/S6' subunits of 26S proteasome

  • Choi, Jin-Sun;Lee, Do-Hee
    • Animal cells and systems
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    • 제14권1호
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    • pp.1-10
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    • 2010
  • Previously we showed that CHIP, a co-chaperone of Hsp70 and E3 ubiquitin ligase, can promote the degradation of mutant SOD1 linked to familial amyotrophic lateral sclerosis (fALS) via a mechanism not involving SOD1 ubiquitylation. Here we present evidence that CHIP functions in the interaction of mutant SOD1 with 26S proteasomes. Bag-1, a coupling factor between molecular chaperones and the proteasomes, formed a complex with SOD1 in an hsp70-dependent manner but had no direct effect on the degradation of mutant SOD1. Instead, Bag-1 stimulated interaction between CHIP and the proteasome-associated protein VCP (p97), which do not associate normally. Over-expressed CHIP interfered with the association between mutant SOD1 and VCP. Conversely, the binding of CHIP to mutant SOD1 was inhibited by VCP, implying that the chaperone complex and proteolytic machinery are competing for the common substrates. Finally we observed that mutant SOD1 strongly associated with the 19S complex of proteasomes and CHIP over-expression specifically reduced the interaction between S6/S6' ATPase subunits and mutant SOD1. These results suggest that CHIP, together with ubiquitin-binding proteins such as Bag-1 and VCP, promotes the degradation of mutant SOD1 by facilitating its translocation from ATPase subunits of 19S complex to the 20S core particle.

Molecular Cloning, Bioinformatics Analysis and Expression Profiling of a Gene Encoding Vacuolar-type $H^+-ATP$ Synthetase (V-ATPase) c Subunit from Bombyx mori

  • Lu, Peng;Chen, Keping;Yao, Qin;Yang, Hua-Jun
    • International Journal of Industrial Entomology and Biomaterials
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    • 제15권2호
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    • pp.115-122
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    • 2007
  • As the genome of B.mori is available in GenBank and the EST database of B.mori is expanding, identification of novel genes of B.mori is conceivable by data-mining techniques. We used the in silico cloning method to get the vacuolar-type $H^+-ATP$ synthetase (V-ATPase) c subunit (16 kDa proteolipid subunit) gene of B.mori and analysed with bioinformatics tools. The result was confirmed by RT-PCR and sequencing. The V-ATPase c subunit cDNA contains a 468 bp ORF. The ORF encoded a 155-residue protein that showed extensive homology with V-ATPase c subunits from other 15 species and contained four membrane-spanning helices. Tissue expression pattern analysis revealed that V-ATPase c expressed strongly in Malpighian tubules, not in fat body. This gene has been registered in GenBank under the accession number EU082222.

계 골격근에서 15S ATPase의 순수분리 및 특성연구 (Purification and Characterization of a 15S Arpase from Chick Skeletal Muscle)

  • 심규석;채광수
    • 한국동물학회지
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    • 제37권4호
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    • pp.524-530
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    • 1994
  • An Arpase complex has been purified to apparent homogeniety from the extract of chick skeletal muscle using conventional column chromatographies and glycerol density gradient centrifugation. This eWe has a sedimentation coefficient of 15S as determined by the gradient centrifugation and therefore is referred to as the 15S ATPase. It behaves as a 600-kOa molecule upon gel filtration analysis using a Superose-6 column. However, the ATPase runs as a 95-kDa polvpeptide when analyzed by polvacrvlamide gel electrophoresis in the presence of sodium dodecyl sulfate. Thus, the Arpase is likely to consist of six identical subunits of 95 KDa. It has a Km value of 0.6 mM for ATP and is maximally active at pH 9.

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흰쥐 뇌에서 발현되는 16 kDa Vacuolar (H$^{+}$)-ATPase의 유전자 클로닝 (Moleculay Cloning of the cDNA Encoding the 16 kDa Subunit of V-ATPase in Rat Brain)

  • 신송우;유민
    • 대한의생명과학회지
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    • 제6권3호
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    • pp.165-170
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    • 2000
  • Vacuolar (H$^{+}$)-ATPase (V-ATPase)는 multi-subunit로 구성된 단백질로서, proton pumping을 통해 세포내 산성화반응에 관여를 한다. 최근에 이 단백질이 synaptic vesicle에서도 발견된 것으로 보아 뇌 신경전달에 중요한 역할을 수행할 것으로 추정하고 있다. 우리는 흰쥐 뇌에서 분리한 mRNA를 주형으로 한 PCR 반응에서 16 kDa subunit의 V-ATPase cDHA를 클로닝할 수 있었고, 이의 염기서열 또한 결정하였다. 분리된 뇌 16 kDa V-ATPase의 coding sequence는 전체 468 bp로서 간에서 보고되었던 것과 동일한 크기였다. 단지 3' 말단의 염기 하나가 A에서 C로 바뀌어 있었는데 모두 alanine (GCA, GCC)을 지정하기 때문에 단백질의 일차구조에는 변화가 없는 것으로 확인되었다. 한편 rat brain cDNA library에서도 동일한 clone이 분리되었는데 역시 같은 부분에서 polymorphism이 발견되었고, RNA splicing 등 더 이상의 조직특이적 변화는 없었다. 본 연구는 16 kDa V-ATPase의 뇌에서의 기능과 신경말단에서의 neurotransmission 및 synaptic vesicle의 재순환 기전을 이해하는데 유용한 정보가 될 것이다.

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Na,K-ATPase와 IgE-Dependent Histamine Releasing Factor의 결합에 영향을 미치는 Protein Kinase C Isotype에 관한 연구 (PKC Isotype that Affects the Interaction of HRF with Na, K-ATPase)

  • 손원주;이경림
    • 한국미생물·생명공학회지
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    • 제33권4호
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    • pp.260-266
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    • 2005
  • 본 실험에서는 MRF가 다량 존재하는 RBL-2H3 세포주에 다양한 PKC isotype별 억제제를 처리하여 in vitro상에서 Na, K-ATPase $\alpha$1L3를 이용한 pull-down assay와 RBL-2H3 세포를 이용한 membrane fractionation을 실시하였다. 그 결과 HRF는 in vitro에서 $\alpha$1L3와 결합한다는 사실을 재확인 할 수 있었고 실제 세포주 내에서 Na,K-ATPase와 결합한다는 것을 알 수 있었다. 사용한 약물로부터 PKC $\alpha,\;\beta,\;\delta$뿐 아니라 protein phosphatase 2B(PP2B)도 HRF와 $\alpha$1L3의 결합에 관여한다는 사실을 알 수 있었다. 또한 이들 PKC, PP2B에 의해 인산화된 HRF 분자는 cytosolic fraction으로 이행할 수 있으며 이러한 결과는 탈인산화된 HRF가 Na,K-ATPase와 결합하여 Na, K-ATPase의 기능을 조절한다고 추정할 수 있다. 그러나 약물자체가 histamine 분비에 영향을 미칠 수 있으며 cytosolic HRF보다 exocytosis된 HRF가 histamine를 더 분비하도록 할 수 있으므로, 약물을 전처리한 세포에 외부에서 HRF를 첨가하여 histamine이 유리되는 정도가 어떻게 변화하는지를 HRF를 가하지 않은 결과와 비교해야 할 것이다.

15S ATPase와 진핵세포에 존재하는 Mg2+-ATPase의 동질성 및 계 골격근에서 분리된 26S 단백질 분해효소와의 면역반응에 관한 연구 (Identity of the 155 ATPase with the Eukarvotic Mg"'-Arpase and Its Immunoreactivitv to the 26S protease Complex from Chick Skeletal Muscle)

  • 심규석;채광수
    • 한국동물학회지
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    • 제37권4호
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    • pp.531-537
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    • 1994
  • Partial internal amino acid sequences of the 15S ATPase from chick skeletal muscle were determined and found to be identical to the corresponding regions of the Mg2+_ATPase from Xenopus laevis oocytes, that is a close homolog of N-ethvlmaleimide-sensitive factor (called NSF) in hamster and Sec18p in yeast, both of which are believed to plaN an essential role in vesicle fusion in secretory process. Thus, the 15S Arpase in chick skeletal muscle maw also belong to a protein family of the "vesicle fusion proteins". Unlike the Mg2'-Afpase with an isoelectric point (pl) of 5.5, however, the 15S Arpase was separated into four spots with pls of 4.9,6.4 and 6.9 upon analysis by twoiimensional gel electrophoresis. In addition, the anti-15S ATPase IgG was found to be capable of interacting with the 265 protease complex upon analysis by immunoprecipitation. Moreover, immunoblot analysis revealed that the anti-155 Arpase IgG recognizes three subunits, ko of which show the same mobilities as the 510-kDa subunit 4 and 48-kDa subunit 7 of the 26S protease complex that are known to contain a highly consented ATP-binding motif. These results surest that a common antigenic site, likely the consensus nucleotide-binding site, exists in the 15S ATPase and the 26S pretense complex and hence both the enzymes maw also be related ATPases.d ATPases.

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Studies on the Membrane Topology of the (Na, K) ATPase

  • Lee, Kyunglim-Yoon
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1996년도 춘계학술대회
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    • pp.181-181
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    • 1996
  • The (Na, K) ATPase is a membrane ion transporting ATPase composed of an ${\alpha}$ catalytic subunit and a ${\beta}$ glycoprotein subunit. The topology of the rat ${\alpha}$1 and ${\beta}$1 subunits has been studied by insertion of epitope(s) : at the NH2-terminus and COOH-terminus and between Glu117 and Glul18, Lys828 and Arg829, Gln900 and Trp901, and Va1939 and Phe940 of the ${\alpha}$ subunit; and at the NH2-terminus and COOH-terminus and between Glu228 and Tyr229 of the ${\beta}$ subunit. The epitope-tagged ${\alpha}$l, constructs were expressed in HeLa cells to select for stable cell lines expressing a functional (Na, K)ATPase. All constructs, except for the one tagged between Gln900 and Trp901, resulted in ouabain-resistant colonies indicating that modified proteins retained functional integrity. The epitope-tagged ${\beta}$ constructs were transiently expressed in Cos-7 cells. The orientation of the epitopes with respect to the cell membrane was revealed by indirect immunofluorescence performed on permeabilized and non-permeabilized cells expressing the (Na, K)ATPase chains. The results indicate that the ${\alpha}$ subunit has 4 transmembrane segments in the COOH terminal membrane bound domain between residues 760 and 938, and that both the NH2-terminus and the COOH-terminus are in the cytosol; it was not determined whether there are more transmembrane segments between residue 938 and the COOH-terminus. The ${\beta}$ subunit has only one transmembrane spanning region with the NH2-terminus in the cytosol and the COOH-terminus on the extracytoplasmic surface of the plasma membrane.

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염스트레스가 담배식물의 Protein, ATPase 및 Peroxidase 활성에 미치는 영향 (Effects of Salt Stress on Protein Content, ATPase and Peroxidase Activities in Tobacco.)

  • 이상각;강병화;이학수;배길관
    • 한국환경농학회지
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    • 제17권4호
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    • pp.296-300
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    • 1998
  • 본 실험은 담배에서 염스트레스에 따른 생리적 반응의 연구결과(제1보)를 기초로, NaCl를 농도별로 처리하여 생체내에서 일어나는 생화학적인 변화의 구명을 통해 염해기작의 기초자료로 얻고자 수행한 결과를 요약하면 다음과 같다. 총단백질과 가용성단백질은 염농도가 높아질수록 감소하였으며 처리간에는 120mM까지는 완만히 감소하였고, 150mM에서는 급격한 감소를 나타냈다. 전기영동 패턴은 염농도의 증가에 따라 새로운 polypeptide band의 생성과 소멸은 없었으며 약 74Kd의 polypeptide band에서 30mM과 60mM까지는 뚜렷한 양이 증가하였고 90mM부터는 감소하였다. 엽록소함량은 염농도의 증가에 따라 감소하였으며 특히 염해에 의한 반응은 엽록소b보다는 엽록소a가 민감하였다. ATPase활성과 peroxidase의 활성은 염농도가 높아질수록 120mM까지는 일정하게 증가하였으나 150mM에서 급격히 증가하여 담배의 염해의 생화학적인 제한범위는 120mM로 나타났다.

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황연해독탕(黃連解毒湯)이 자발적(自發的) 고혈압(高血壓) 백서(白鼠)의 혈압(血壓) 신장(腎臟) 기능(機能)에 미치는 영향(影響) (Effect of Hwangryunhaedok-tang on Blood Pressure and Renal Functions in Spontaneously Hypertensive Rats)

  • 국윤범
    • 대한한의학방제학회지
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    • 제10권1호
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    • pp.113-129
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    • 2002
  • The present study designed to investigate whether hwangryunhaedok-tang show an anti-hypertensive effect and elucidate its possible mechanism in spontaneously hypertensive rats. The systolic blood pressures (SBP) were significantly decreased as an oral administration of hwangryunhaedok-tang compared with their control group. The urine volume was significantly increased by administration of hwangryunhaedok-tang but urinary sodium (UNaV), potassium (UKV), chloride excretion (UCIV) were not remarkably affected. The urinary creatinine excretion rate (UcrV) was significantly increased in rats administered with hwangryunhaedok-tang in association with increase of creatinine clearance (Ccr). The urine osmolality (Uosmol) was significantly decreased in SHR administered with hwangryunhaedok-tang without being changed in solute-free water reabsorption ( TcH20). The expressions of Aquaporin 2 (AQP-2). 3 and ${\alpha}\;1$, ${\beta}\;1$ subunits of Na.K-ATPase were determined by Western blot analysis to assess the role of these proteins in association with changes of renal functions in SHR administered with hwangryunhaedok-tang. The expression of AQP-2 and 3 protein was significantly down-regulated in the kidney of SHR administered with hwangryunhaedok-tang compared with those in control rats without being altered expression of ${\alpha}\;1$, ${\beta}\;1$ subunits of Na,K-ATPase. In the in vitro assay, Angiotensin converting enzyme (ACE) was inhibited by hwangryunhaedok-tang in a dose-dependent manner. Berberine and/or palmatine, which are well known as a main components of hwangryunhaedok-tang, also have an ACE inhibitory effects in a dose-dependent manner. Taken together, these results suggest that hwangryunhaedok-tang lowered blood pressure through the increase of diuresis caused by down-regulation of water channels and the inhibition of Angiotensin converting enzyme.

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