• Journal of Microbiology and Biotechnology
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• v.30 no.2
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• pp.306-312
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• 2020

Despite the importance of brown adipocytes as a therapeutic target for the prevention and treatment of obesity, the molecular mechanism underlying brown adipocyte differentiation is not fully understood. In particular, the role of post-translational modifications in brown adipocyte differentiation has not been extensively studied. Histidine phosphorylation is increasingly recognized an important process for protein post-translational modifications. In this study, we show that histidine phosphorylation patterns change during brown adipocyte differentiation. In addition, the expression level of protein histidine phosphatase 1 (PHPT1), a major mammalian phosphohistidine phosphatase, is reduced rapidly at the early phase of differentiation and recovers at the later phase. During white adipocyte differentiation of 3T3-L1 preadipocytes, however, the expression level of PHPT1 do not significantly change. Knockdown of PHPT1 promotes brown adipocyte differentiation, whereas ectopic expression of PHPT1 suppresses brown adipocyte differentiation. These results collectively suggest that histidine phosphorylation is closely linked to brown adipocyte differentiation and could be a therapeutic target for obesity and related metabolic diseases.

• Mass Spectrometry Letters
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• v.11 no.3
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• pp.52-58
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• 2020

Histidine phosphorylation (pHis) is increasingly recognized as an important post translational modification (PTM) in regulating cellular functions in eukaryotes. In order to clarify the role of pHis in mammalian cell signaling system, a global phosphorylation study was performed in human prostate cancer cells, PC-3M, using a TiO₂ affinity chromatography. A total number of 307 pHis sites were identified on the 268 proteins among total identified 9,924 phosphorylation sites on 3,316 proteins. In addition, 22 pHis proteins were classified in enzyme category. This report provides the first database for the study of pHis in prostate cancer cells.

• Journal of Life Science
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• v.6 no.3
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• pp.213-218
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• 1996

Symbionin, ahomologue of E. coli GroEL, produced by an intracellular symbiont of the pea aphid , has molecular chaperone activity bothin vitro and in vivo, and it is able to tarnsfer its high-energy phospholy group to other compounds through its autophosphorylation and phosphotransferase activity. The symbionin is a novel histidine protein Kinase and a senor molecular of the two-component pathway.

• BMB Reports
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• v.40 no.5
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• pp.708-714
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• 2007

The two-component signal transduction, which typically consists of a histidine kinase and a response regulator, is used by bacterial cells to sense changes in their environment. Previously, the SphS-SphR histidine kinase and response regulator pair of phosphate sensing signal transduction has been identified in Synechocystis sp. PCC 6803. In addition, some response regulators in bacteria have been shown to be cross regulated by low molecular weight phosphorylated compounds in the absence of the cognate histidine kinase. The ability of an endogenous acetyl phosphate to phosphorylate the response regulator, SphR in the absence of the cognate histidine kinase, SphS was therefore tested in Synechocystis sp. PCC 6803. The mutant lacking functional SphS and acetate kinase showed no detectable alkaline phosphatase activity under phosphate-limiting growth conditions. The results suggested that the endogenous acetyl phosphate accumulated inside the mutants could not activate the SphR via phosphorylation. On the other hand, exogenous acetyl phosphate could allow the mutant lacking functional acetate kinase and phosphotransacetylase to grow under phosphate-limiting conditions suggesting the role of acetyl phosphate as an energy source. Reverse transcription PCR demonstrated that the transcripts of acetate kinase and phospho-transacetylase genes in Synechocystis sp. PCC 6803 is up-regulated in response to phosphate limitation suggesting the importance of these two enzymes for energy metabolism in Synechocystis cells

• Journal of Life Science
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• v.33 no.2
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• pp.176-182
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• 2023

The stems of Dendrobium moniliforme are used in traditional Oriental medicine as a Yin tonic to nourish the stomach, promote the production of body fluid, and reduce fever. This study investigated the effects of the aqueous extract of D. moniliforme stems (DME) on mast cell degranulation and the expression of tumor necrosis factor-α (TNF-α), interleukin-4 (IL-4), and histamine-synthesizing enzyme histidine decarboxylase (HDC). We used rat mast cell line RBL-2H3 cells and stimulated them with PMA plus calcium ionophore (PMACI). Pretreatment with DME significantly inhibited PMACI-induced β-hexosaminidase release and the expression of TNF-α, IL-4, and HDC. Furthermore, DME suppressed PMACI-induced nuclear translocation of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and activator protein 1 (AP-1). In addition, HDC expression was inhibited by SP600125 (JNK inhibitor), PD98059 (ERK inhibitor), and SB203580 (p38 kinase inhibitor). Finally, the phosphorylation of p38 kinase, extracellular signal-regulated kinase 1/2 (ERK1/2), and c-Jun N-terminal kinase (JNK) was inhibited by pretreatment with DME. These results suggest that DME has inhibitory effects against degranulation, cytokine (TNF-α and IL-4) and HDC expression, and that HDC expression is mediated by MAPK signaling. These findings suggest that DME may have therapeutic potential in the treatment of hypersensitive and inflammatory diseases.

• Journal of Microbiology and Biotechnology
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• v.16 no.6
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• pp.988-992
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• 2006

The ptsHI operon from Leuconostoc mesenteroides ssp. mesenteroides SY1 (L. mesenteroides SY1), a strain isolated from kimchi, was cloned and characterized. The ptsH open reading frame (ORF) was 273 bp in size, which can encode a protein of 90 amino acid residues with a molecular weight of 9,212 Da. The pfsI ORF was 1,719 bp in size, which was capable of encoding a protein of 572 amino acids with a molecular mass of 62,549 Da. ptsH and pfsI genes were transcribed as a single transcript of 2.0 kb in size regardless of carbon sources, supporting the operon structure. Although the deduced amino acid sequences of the HPr and EI were highly homologous with those of other Gram-positive bacteria, an additional amino acid (glutamine at the $3^{rd}$ amino acid) was present in HPr from L. mesenteroides SY1. Phosphorylation sites of HPr included the histidine residue ($16^{th}$) and serine residue ($47^{th}$). Mutant HPrs, in which each phosphorylation site was mutated into alanine, were obtained, and phosphorylation with HPr and mutated HPrs showed that HPr was phosphorylated at the serine residue ($47^{th}$) by HPr kinaseiphosphorylase (HPr K/P).

• Journal of Microbiology and Biotechnology
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• v.8 no.3
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• pp.214-221
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• 1998

A Brevibacterium ammoniagenes gene coding for glucose/mannose-specific enzyme II ($EII^{Glc}$) of the phosphoenolpyruvate-dependent phosphotransferase system (PTS) was cloned by complementing an Escherichia coli mutation affecting a ptsG gene, and the complete DNA nucleotide sequence was determined. The cloned gene was identified to be a ptsG, which enables the E. coli transportment to use glucose more efficiently than mannose as the sole carbon source in an M9 minimal medium. The ptsG gene of B. ammoniagenes consists of an open reading frame of 1,983 nucleotides putatively encoding a polypeptide of 661 amino acid residues and a TAA stop codon. The deduced amino acid sequence of the B. ammoniagenes $EII^{Glc}$ shows, at $46\%$, the highest degree of sequence similarity with the Corynebacterium glutamicum EII specific for both glucose and mannose. In addition, the $EII^{Glc}$ shares approximately $30\%$ sequence similarities with sucrose-specific and ${\beta}$-glucoside-specific EIIs of the several bacteria belonging to the glucose-PTS class. The 161-amino-acid C-terminal sequence of $EII^{Glc}$ is also similar to that of E. coli enzyme $IIA^{Glc}$, specific for glucose ($EIIA^{Glc}$). The B. ammoniagenes $EII^{Glc}$ consists of three domains; a hydrophobic region (EIIC) and two hydrophilic regions (EIIA, EIIB). The arrangement of structural domains, IIBCA, of the $EII^{Glc}$ is identical to those of EIIs specific for sucrose or ${\beta}$-glucoside. While the domain IIA was removed from the B. ammoniagenes $EII^{Glc}$ the remaining domains IIBC were found to restore the glucose and mannose-utilizing capacity of E. coli mutant lacking $EII^{Glc}$ activity with $EIIA^{Glc}$ of the E. coli mutant. $EII^{Glc}$ contains a histidine residue and a cysteine residue which are putative phosphorylation sites for the protein.