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Kim, Jong-Il
- Journal of Microbiology
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- v.44 no.5
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- pp.508-514
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- 2006
In this study, the double-stranded DNA-dependent activities of Deinococcus radiodurans RecA protein (Dr RecA) were characterized. The interactions of the Dr RecA protein with double-stranded DNA were determined, especially dsDNA-dependent ATP hydrolysis by the Dr RecA protein and the DNA strand exchange reaction, in which multiple branch points exist on a single RecA protein-DNA complex. A nucleotide cofactor (ATP or dATP ) was required for the Dr RecA protein binding to duplex DNA. In the presence of dATP, the nucleation step in the binding process occurred more rapidly than in the presence of ATP. Salts inhibited the binding of the Dr RecA protein to double-stranded DNA. Double-stranded DNA-dependent ATPase activities showed a different sensitivity to anion species. Glutamate had only a minimal effect on the double-stranded DNA-dependent ATPase activities, up to a concentration of 0.7 M. In the competition experiment for Dr RecA protein binding, the Dr RecA protein manifested a higher affinity to double-stranded DNA than was observed for single-stranded DNA.
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김미영;이경림
- Biomolecules & Therapeutics
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- v.4 no.4
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- pp.398-401
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- 1996
The glucose transporters found in the plasma membrane of all animal cells are known to have 12 putative transmembrane domains. Among 7 cytoplasmic loops, the fourth loop is the largest one. Since previous studies showed that cofilin, an actin-modulating protein, was found to interact with the largest cytoplasmic loop of (Na, K)ATPase, we tested if cofilin interacts with the largest cytoplasmic loop of Glut4. We demonstrated by the two-hybrid system that the largest cytoplasmic loop of Glut4 did not show any interaction with cofilin, suggesting that cofilin is not required for the membrane targeting process of other membrane proteins but only for a P-type ATPase.
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Lee, Kee-Ho;Lee, Je-Ho;Lee, Soo-Yong;Park, Sang-Yoon;Lee, Seung-Hoon;Yun, Taik-Koo;Ryu, Young-Wun;Lim, In-Kyoung
- Journal of Radiation Protection and Research
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- v.15 no.2
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- pp.1-6
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- 1990
An attempt was made to test the possibility of a major role for the $Na^{+}-K^{+}$ adenosine triphosphatase (ATPase)system in the diuresis induced by uranyl nitrate(UN). Fisher 344 rats were intravenously injected with UN(5 mg/kg, 15 mg/kg and 30 mg/kg). Urinary excretion of $Na^{+}\;and\;K^{+}$ significantly increased in 24 h exposure on the UN and then decreased below the normal level 3 days after the treatment. $Na^{+}-K^{+}$ ATPase activity of kidney was significantly inhibited in high dosages of UN 15mg/kg and UN 30 mg/kg 3-5 days after injection. And then the recovery of the enzyme activity was observed within 5-10 days after injection, at which the regeneration of the tubular cells occurred.
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Lee, Shin-Woong;Lee, Jeung-Soo
- YAKHAK HOEJI
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- v.36 no.2
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- pp.129-136
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- 1992
The effects of ginseng saponins, gypsophila saponin, sodium dodecyl sulfate(SDS), and Triton X-100 on membrane $K^+-dependent$ phosphatase activity which is lipid dependent and represents dephosphorylation step of the complete Na+, $K^+-ATPase$ reaction were investigated in this study to elucidate whether the effects of ginseng saponins are due to the detergent action, using sarcolemma enriched preparation isolated from dog ventricle. $Na^+$, $K^+-ATPase$ and $K^+-dependent$ phosphatase activities of cardiac sarcolemma were about $143\;{\mu}mol$ Pi/mg protein/hr and $34\;{\mu}mol$ p-nitrophenol/mg protein/hr, respectively. While ginseng saponins (triol>total>diol) inhibited $K^+-dependent$ phosphatase activity, gypsophila saponin, and low dose of SDS($0.4\;{\mu}g/{\mu}g$ protein), and Triton X-100 ($0.6\;{\mu}g/{\mu}g$ protein) increased the enzyme activity, indicating disruptive effect of detergents on membrane barriers. The activating effect of low doses of Triton X-100 on membrane $K^+-dependent$ phosphatase appeared at concentration decreasing light scattering. However, the inhibitory effect of ginseng saponin appeared before a decrease in light scattering. These results suggest that low concentrations of ginseng saponins inhibit the membrane $K^+-dependent$ phosphatase by interacting directly with enzyme before membrane disruption.
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Yong Hwan Jin;Eung Jae Yoo;Yeun Kyu Jang;Seung Hae Kim;Chee-Gun Lee;Rho Hyun Seong;Seung Hwan Hong;Sang Dai Park
- Animal cells and systems
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- v.2 no.4
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- pp.539-543
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- 1998
Hrp1, of Schizosaccharomyces pombe, is a new member of the SW12/SNF2 protein family that contains a chromodomain and a DNA binding domain as well as ATPase/7 helicase domains. This configuration suggests that Hrp1 could be a homolog of mouse CHD1, which is thought to function in altering the chromatin structure to facilitate gene expression. To understand the enzymatic nature of Hrp1 we purified the 6-Histidine-tagged Hrp1 protein (6$\times$His-Hrp1) to homogeneity from a S. pombe Hrp1-overexpressing strain and hen examined its biochemical properties. We demonstrate that the purified 6$\times$His-Hrp1 protein exhibited a DNA-binding activity with a moderate preference to the (A＋T)-rich tract in double-stranded NA via a minor groove interaction. However, we failed to detect any intrinsic DNA helicase activity from the purified Hrp1 like other SW12/SNF2 proteins. These observations suggest that the DNA binding activities of Hrp1 may be involved in the remodeling of the chromatin structure with DNA-dependent ATPase. We propose that Hrp1 may function in heterochromatins as other proteins with a chromo- or ATPase/helicase domain and play an important role in the determination of chromatin architecture.
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