• Proceedings of the Korean Society for Bioinformatics Conference
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• 2003.10a
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• pp.5-5
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• 2003

The purple acid phosphatases comprise a family of binuclear metal-containing enzymes. The metal centre contains one ferric ion and one divalent metal ion. Spectroscopic studies of the monomeric, ${\sim}$36 kDa mammalian purple acid phosphatases reveal the presence of an Fe(III)Fe(II) centre in which the metals are weakly antiferromagnetically coupled, whereas the dimeric, ${\sim}$110 000 kDa plant enzymes contain either Fe(III)Zn(II) or Fe(III)Mn(II). The three dimensional structures of the red kidney bean and pig enzymes show very similar arrangements of the metal ligands but some significant differences beyond the immediate vicinity of the metals. In addition to the catalytic domain, the plant enzyme contains a second domain of unknown function. A search of sequence databases was undertaken using a sequence pattern which includes the conserved metal-binding residues in the plant and animal enzymes. The search revealed the presence in plants of a 'mammalian-type' low molecular weight purple acid phosphatase, a high molecular weight form in some fungi, and a homologue in some bacteria. The catalytic mechanism of the enzyme has been investigated with a view to understanding the marked difference in specificity between the Fe-Mn sweet potato enzyme, which exhibits highly efficient catalysis towards both activated and unactivated phosphate esters, and other PAPs, which hydrolyse only activated esters. Comparison of the active site structures of the enzymes reveal some interesting differences between them which may account for the difference. The implications fur understanding the physiological functions of the enzymes will be discussed.

• Journal of Microbiology and Biotechnology
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• v.18 no.2
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• pp.365-368
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• 2008

Calcium entry through $Ca_v3.2Ca^{2+}$ channels plays essential roles for various physiological events including thalamic oscillation, muscle contraction, hormone secretion, and sperm acrosomal reaction. In this study, we examined how protein tyrosine phosphatases or protein tyrosine kinases affect $Ca_v3.2Ca^{2+}$ channels reconstituted in Xenopus oocytes. We found that $Ca_v3.2$ channel activity was reduced by 25% in response to phenylarsine oxide (tyrosine phosphatase inhibitor), whereas it was augmented by 19% in response to Tyr A47 or herbimycin A (tyrosine kinase inhibitors). However, other biophysical properties of $Ca_v3.2$ currents were not significantly changed by the drugs. These results imply that $Ca_v3.2$ channel activity is capable of being increased by activation of tyrosine phosphatases, but is decreased by activation of tyrosine kinases.

• Journal of Microbiology
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• v.39 no.4
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• pp.314-320
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• 2001

Macrophages stimulated by lipopolysaccharide(LPS) from gram negative bacteria undergo activation of a group of immediate early genes including Rantes. The mouse Rantes gene promoter region contains an LPS rsponsive element(LPE) We detected 3 specific bands termed B1, B2 and 3 formed by the interaction of the LPE and proteins found in LPS-stimulated RAW 367.7 cells. An additional band B4 was determined to be an Ap-1 binding protein. The B1 band appears within 1 hour of LPS nuclear extracts from LPS-stimulation, and this protein kinase enhances B1 and formation. The B1 band can be converted to band B2/B3 by adding specific heparin column fraction purified Ser/Thr specific protein phosphatases PP-1 and PP-2A can stimulate the same conversion to about the same extent. Thus, the formation of the LRE sequence binding complex appears to be regulated by Ser/Thr protein kinase and one or more Ser/Thr specific phosphatases. At least four proteins are involved in the trgulation of the LRE-dependent Rants experssion: two binding factors that bind directly to the target sequences. and two factors that control their binding. The future purification and characterization of these binding pro-teins will reveal in detail the mechanism of Rantes gene activation after LPS stimulation.

• BMB Reports
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• v.54 no.9
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• pp.451-457
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• 2021

Over the last decades, research has focused on the role of pleckstrin homology (PH) domain leucine-rich repeat protein phosphatases (PHLPPs) in regulating cellular signaling via PI3K/Akt inhibition. The PKB/Akt signaling imbalances are associated with a variety of illnesses, including various types of cancer, inflammatory response, insulin resistance, and diabetes, demonstrating the relevance of PHLPPs in the prevention of diseases. Furthermore, identification of novel substrates of PHLPPs unveils their role as a critical mediator in various cellular processes. Recently, researchers have explored the increasing complexity of signaling networks involving PHLPPs whereby relevant information of PHLPPs in metabolic diseases was obtained. In this review, we discuss the current knowledge of PHLPPs on the well-known substrates and metabolic regulation, especially in liver, pancreatic beta cell, adipose tissue, and skeletal muscle in relation with the stated diseases. Understanding the context-dependent functions of PHLPPs can lead to a promising treatment strategy for several kinds of metabolic diseases.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.463-481
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• 2022

Phosphorous (P) is considered to be one of the key essential elements demanded by crop plants. Approximately 70 - 90% of phosphatic fertilizers applied to crops are fixed in soil as Ca, Fe, and Al metal cations, which are insoluble and thus not readily available for plant uptake. Therefore, most soils are deficient in plant available P. This is usually rectified by applying phosphate fertilizers continuously, although this is not economically viable or environmentally acceptable. The present paper reviews the mechanisms involved with phosphate solubilization and mineralization by phosphate solubilizing microorganisms (PSMs) with the associated factors that determine the success. PSMs are effectively involved in mediating the bioavailability of soil P. Their contribution includes mineralization of organic P solubilization of inorganic P minerals, and storing sizable amounts of P in biomass through different mechanisms such as the production of organic and inorganic acids, H₂S, siderophores, exopolysaccharides, and production of enzymes such as phosphatases, phytase, and phosphonatases/C-P lyases, which are capable of chelating the metal ions, forming complexes, and making plant available P. PSMs manifest a wide range of metabolic functions in different environments, resulting in significantly higher plant growth, enhanced soil properties, and increased biological activities. Therefore, development of bio-inoculants with efficient novel PSM strains and further investigations on exploring such strains from diverse ecological niches with multifunctional plant-growth-promoting traits are needed.

• Bulletin of the Korean Chemical Society
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• v.35 no.11
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• pp.3385-3388
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• 2014

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.421-421
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• 2005

• Proceedings of the Korean Biophysical Society Conference
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• 2001.06a
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• pp.20-20
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• 2001

The PTEN tumor suppressor is mutated in diverse human cancers and in hereditary cancer predisposition syndromes. PTEN is a phosphatase that can act on both polypeptide and phosphoinositide substrates in vitro. The PTEN structure reveals a phosphatase domain similar to protein phosphatases but having an enlarged active site important for the accommodation of the phosphoinositide substrate.(omitted)

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.1
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• pp.44-52
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• 2016

Plants response to phosphate starvation include the changes of activity of some enzymes, such as phosphatases, fructose-1,6-bisphosphatase, sucrose-phosphate synthase and nitrate reductase. In this study, to determine the effects of phosphate starvation on the change of activities of acid and alkaline phosphatase, fructose-1,6-bisphosphatase, sucrose-phosphate synthase, and nitrate reductase were studied in melon seedlings (Cucumis melo L.). The content of the protein and chlorophyll tended to relatively reduced in melon seedlings subjected to phosphate starvation. Acid phosphatase activity in first and second leaves of melon seedlings was relatively higher than that of third and fourth leaves of seedlings in 14 days after phosphate starvation treatment, respectively. Active native-PAGE band patterns of acid phosphatase in melon leaves showed similar to activities of acid phosphatase, whereas alkaline phosphatase activity was different from the change in the activity of acid phosphatase. Inorganic phosphate content in melon seedlings leaves was constant. The changes of Fructose-1,6-bisphosphatase and sucrose phosphate synthase activities showed similar patterns in melon seedlings leaves, and between these enzymes activities and phosphate nutrition negatively related. Fructose-1,6- bisphosphatase and sucrose phosphate synthase activities showed significant difference in second and fourth leaves, but nitrate reductase showed significant difference in first and second leaves in 14days after phosphate starvation treatment. We concluded that phosphate nutrition could affect the distribution of phosphate, carbon and nitrogen in melon seedlings.

• Journal of Ginseng Research
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• v.28 no.2
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• pp.78-86
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• 2004

Panax ginseng occupies an important role in the folk medicine of China, Korea and Japan. The present study was undertaken to determine the radioprotective efficacy of ginseng root extract in the liver of Swiss albino mice. The animals were divided into 4 groups. Group I-Only vehicle was administered. Group II-The animals received 10 mg/kg body weight ginseng root extract i.p. for 4 consecutive days. Group III-Animals were irradiated with 8Gy gamma radiation at the dose rate of 1.69 Gy/min at the distance of 80 ems. Group IV-Animals were given by ginseng root extract (10 mg/kg body weight) continuously for 4 days and on 4th day they were irradiated with 8 Gy gamma radiation after 30 min. The animals from above groups were autopsied on 1,3,7,14 and 30 days. Biochemical estimations of phosphatases (acid ＆ alkaline), LDH (lactate dehydrogenase), LPO (lipid peroxidation) and GSH (reduced glutathione) in liver and SGOT (serum glutamate oxaloacetate transaminase), SGPT (serum glutamate pyruvate transaminase) and alkaline phosphatase in serum were done. In ginseng treated group acid phosphatase (ACP), alkaline phosphatase (ALP), LPO and LDH in liver and SGOT, SGPT and alkaline phosphatase in serum did not show any significant alteration. However, a significant increase in GSH content in liver was recorded. In irradiated group there was a significant increase in ACP, ALP and LPO content in liver and SGOT ＆ SGPT in serum was noted. Whereas, a significant decrease was recorded in GSH and LDH activity in liver and alkaline phosphatase activity in serum. Pretreatment of ginseng with radiation significantly alters the biochemical parameters in liver and serum. A significant decline in ACP, ALP activity and LPO content in liver and SGOT and SGPT activity in serum was observed. However, a significant increase in GSH content and LDH activity in liver and ALP activity in serum was estimated. The present study suggests that pretreatment of ginseng before irradiation significantly protects the liver and maintains the enzyme activity.