• Title/Summary/Keyword: Intracellular localization

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Candidacidal Effects of Rev (11-20) Derived from HIV-1 Rev Protein

  • Lee, Juneyoung;Lee, Dong Hwan;Lee, Dong Gun
    • Molecules and Cells
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    • v.28 no.4
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    • pp.403-406
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    • 2009
  • Rev is an essential regulatory protein for HIV-1 replication. Rev (11-20) is known as the significant region regarding the function of a nuclear entry inhibitory signal (NIS) of Rev. In this study, anticandidal effects and mechanism of action of Rev (11-20) were investigated. The result exhibited that Rev (11-20) contained candidacidal activities. To understand target site(s) of Rev (11-20), the intracellular localization of the peptide was investigated. The result showed that Rev (11-20) rapidly accumulated in the fungal cell surface. The cell wall regeneration test also indicated that Rev (11-20) exerted its anticandidal activity to fungal plasma membrane rather than cell wall. The fluorescent study using 1,6-diphenyl-1,3,5-hexatriene (DPH) further confirmed the membrane-disruption mechanism(s) of Rev (11-20). The present study suggests that Rev (11-20) possesses significant potential regarding therapeutic agents for treating fungal diseases caused by Candida species in humans.

Localization of Divalent Cation-Binding Site in the Pore of a Small Conductance $Ca^{2+}$-activated $K^+$ Channel and Its Role in Determining Current-Voltage Relationship

  • Heun Soh;Shin, Na-Rae;Park, Chul-Seung
    • Proceedings of the Korean Biophysical Society Conference
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    • 2002.06b
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    • pp.33-33
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    • 2002
  • In our previous study (Soh and Park, 2001), we proposed that the inwardly rectifying current-voltage (I-V) relationship of small-conductance $Ca^{2+}$-activated $K^{+}$ channels (S $K_{Ca}$ channels) is the result of voltage-dependent blockade of $K^{+}$ currents by intracellular divalent cations. We expressed a cloned S $K_{Ca}$ channel, rSK2, in Xenopus oocytes and further characterized the nature of the divalent cation-binding site by electrophysiological means.(omitted)

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A Blood-brain Barrier Permeable Derivative of 5-Fluorouracil: Preparation, Intracellular Localization, and Mouse Tissue Distribution

  • Im, Jung-Kyun;Biswas, Goutam;Kim, Wan-Il;Kim, Kyong-Tai;Chung, Sung-Kee
    • Bulletin of the Korean Chemical Society
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    • v.32 no.3
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    • pp.873-879
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    • 2011
  • 5-Fluorouracil (5-FU), an anticancer agent was covalently attached to the recently developed sorbitol-based G8 transporter, and the conjugate (7) with FITC was found to have an affinity toward mitochondria and to readily cross BBB to gain an entry into mouse brain. Measured by $IC_{50}$, the conjugate (9) without the fluorophore showed enhanced cytotoxic activity toward two types of multidrug-resistant cell lines. These results strongly suggest that the sorbitol-based G8 transporter can be utilized as a good CNS delivery vector.

Nitrogen Control in Corynebacterium glutamicum: Proteins, Mechanisms, Signals

  • Burkovski, Burkovski;Andreas, Andreas
    • Journal of Microbiology and Biotechnology
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    • v.17 no.2
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    • pp.187-194
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    • 2007
  • In order to utilize different nitrogen sources and to survive in a situation of nitrogen limitation, microorganisms have developed sophisticated mechanisms to adapt their metabolism to a changing nitrogen supply. In this communication, the recent knowledge of nitrogen regulation in the amino acid producer Corynebacterium glutamicum is summarized. The core adaptations of C. glutamicum to nitrogen limitation on the level of transcription are controlled by the global regulator AmtR. Further components of the signal pathway are GlnK, a $P_{II}-type$ signal transduction protein, and GlnD. Mechanisms involved in nitrogen control in C. glutamicum regulating gene expression and protein activity are repression of transcription, protein-complex formation, protein modification by adenylylation, change of intracellular localization, and proteolysis.

Expression of Bone Morphogenetic Protein-2 and Histological Differentiation of Oral Squamous Cell Carcinomas

  • Hamasni, Fatme Mouchref;El Hajj, Fady
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.12
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    • pp.5243-5245
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    • 2016
  • Background and Objective : Bone morphogenic protein-2 (BMP-2) plays an essential role in mesenchymal cell differentiation into osteoblasts، through many intracellular pathways which may also be active in tumors. Invasive oral squamous cell carcinomas account for more than 90% of head and neck malignancies in many cancer registries. They are classified into three types according to epithelial cell differentiation. The present study aimed to identify any relation between BMP-2 expression and tumor histology. Materials and methods: BMP-2 expression was compared immunohistochemically among 30 cases (19 male and 11 female, mean age 48 years) of oral squamous cell carcinoma, Division was into 3 groups (each containing 10 cases) according to the histological grade. Results: No significant correlation between BMP-2 expression and histological grade was observed. Changes in localization and cytoplasmic staining were also not apparent. Conclusion: From the results of this study BMP-2 does not appear to have any application as a prognostic marker for oral squamous cell carcinomas.

Mitochondrial Targeting Domain Homologs Induce Necrotic Cell Death Via Mitochondrial and Endoplasmic Reticulum Disruption

  • Park, Junghee;Han, Ji-Hye;Myung, Seung-Hyun;Chung, Hea-jong;Park, Jae-il;Cho, Ju-Yeon;Kim, Tae-Hyoung
    • Journal of Microbiology and Biotechnology
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    • v.31 no.6
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    • pp.875-881
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    • 2021
  • The mitochondrial targeting domain (MTD) of Noxa contributes to its mitochondrial localization and to apoptosis induction. As a peptide, MTD fused with octa-arginine (R8), a CPP, induces necrosis related to intracellular calcium influx and destruction of mitochondria and endoplasmic reticulum. We searched for homologs of MTD, and compared their cell killing capability when fused with R8. Three of the seven peptides triggered cell death with similar mechanisms. The comparative analysis of peptide sequences showed that four amino acid sites of MTD are critical in regulating necrosis, suggesting the potential to generate artificial, adjustable cytotoxic peptides, which could be effective medicines for many diseases. Thus, homologs functionality could hint to the functions of their belonging proteins.

Biophysical effect of lipid modification at palmitoylation site on the structure of Caveolin 3

  • Ma, Yu-Bin;Kang, Dong-Hoon;Kim, Myeongkyu;Kim, Ji-Hun
    • Journal of the Korean Magnetic Resonance Society
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    • v.23 no.3
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    • pp.67-72
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    • 2019
  • Caveolae are small plasma membrane invaginations that play many roles in signal transduction, endocytosis, mechanoprotection, lipid metabolism. The most important protein in caveolae is the integral membrane protein, caveolin, which is divided into three families such as caveolin 1, caveolin 2, and caveolin 3. Caveolin 1 and 3 are known to incorporate palmitate through linkage to three cysteine residues. Regulation of the protein palmitoylation cycle is important for the cellular processes such as intracellular localization of the target protein, membrane association, conformation, protein-protein interaction, and activity. However, the detailed aspect of individual palmitoylation has not been studied. In the present work, the role of each lipid modification at three cysteines was studied by NMR. Our results suggest that each lipid modification at the natively palmitoylation site has its own roles. For example, lipidations to C106 and C129 are play a role in structural stabilization, however, interestingly, lipid modification to C116 interrupts the structural stabilization.

Molecular Analyses of the Metallothionein Gene Family in Rice (Oryza sativa L.)

  • Zhou, Gongke;Xu, Yufeng;Li, Ji;Yang, Lingyan;Liu, Jin-Yuan
    • BMB Reports
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    • v.39 no.5
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    • pp.595-606
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    • 2006
  • Metallothioneins are a group of low molecular mass and cysteine-rich metal-binding proteins, ubiquitously found in most living organisms. They play an important role in maintaining intracellular metal homeostasis, eliminating metal toxification and protecting against intracellular oxidative damages. Analysis of complete rice genome sequences revealed eleven genes encoding putative metallothionein (OsMT), indicating that OsMTs constitute a small gene family in rice. Expression profiling revealed that each member of the OsMT gene family differs not only in sequence but also in their tissue expression patterns, suggesting that these isoforms may have different functions they perform in specific tissues. On the basis of OsMT structural and phylogenetic analysis, the OsMT family was classified as two classes and class I was subdivided into four types. Additionally, in this paper we also present a complete overview of this family, describing the gene structure, genome localization, upstream regulatory element, and exon/intron organization of each member in order to provide valuable insight into this OsMT gene family.

AlLTPs from Allium species represent a novel class of lipid transfer proteins that are localized in endomembrane compartments

  • Yi, Seung-In;Park, Mee-Yeon;Kim, Ju-Kon;Choi, Yang Do
    • Plant Biotechnology Reports
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    • v.3 no.3
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    • pp.213-223
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    • 2009
  • Lipid transfer proteins (LTPs) are widely distributed in the plant kingdom, but their functions remain elusive. The proteins AlLTP2-4 were isolated from three related Allium plants: garlic (A. sativum L.), Welsh onion (A. fistulosum L.), and Nanking shallot (A. ascalonicum L.). These novel proteins comprise a new class of LTPs associated with the Ace-AMP1 from onion (A. cepa L.). The AlLTP genes encode proteins harboring 132 common amino acids and also share a high level of sequence identity. Protein characteristics and phylogenetic analysis suggest that LTPs could be classified into five distinct groups. The AlLTPs were clustered into the most distantly related plant LTP subfamily and appeared to be restricted to the Allium species. In particular, the number of amino acids existing between the fourth and fifth Cys residue was suggested as a conserved motif facilitating the categorization of all the LTP-related proteins in the family. Unlike other LTPs, AlLTPs harboring both the putative C-terminal propeptide and N-terminal signal peptide were predicted to be localized to cytoplasmic vacuoles. When a chimeric GFP protein fused with both N-terminal and C-terminal AlLTP2 signal peptides was expressed in rice cells, the fluorescence signal was detected in the endomembrane compartments, thereby confirming that AlLTPs are an unprecedented intracellular type of LTP. Collectively, our present data demonstrate that AlLTPs are a novel type of LTP associated with the Allium species.

LAMP-3 (Lysosome-Associated Membrane Protein 3) Promotes the Intracellular Proliferation of Salmonella typhimurium

  • Lee, Eun-Ju;Park, Kwan-Sik;Jeon, In-Sook;Cho, Jae-Woon;Lee, Sang-Jeon;Choy, Hyun E.;Song, Ki-Duk;Lee, Hak-Kyo;Choi, Joong-Kook
    • Molecules and Cells
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    • v.39 no.7
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    • pp.566-572
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    • 2016
  • Lysosomes are cellular organelles containing diverse classes of catabolic enzymes that are implicated in diverse cellular processes including phagocytosis, autophagy, lipid transport, and aging. Lysosome-associated membrane proteins (LAMP-1 and LAMP-2) are major glycoproteins important for maintaining lysosomal integrity, pH, and catabolism. LAMP-1 and LAMP-2 are constitutively expressed in Salmonella-infected cells and are recruited to Salmonella-containing vacuoles (SCVs) as well as Salmonella- induced filaments (Sifs) that promote the survival and proliferation of the Salmonella. LAMP-3, also known as DC-LAMP/CD208, is a member of the LAMP family of proteins, but its role during Salmonella infection remains unclear. DNA microarray analysis identified LAMP-3 as one of the genes responding to LPS stimulation in THP-1 macrophage cells. Subsequent analyses reveal that LPS and Salmonella induced the expression of LAMP-3 at both the transcriptional and translational levels. Confocal Super resolution N-SIM imaging revealed that LAMP-3, like LAMP-2, shifts its localization from the cell surface to alongside Salmonella. Knockdown of LAMP-3 by specific siRNAs decreased the number of Salmonella recovered from the infected cells. Therefore, we conclude that LAMP-3 is induced by Salmonella infection and recruited to the Salmonella pathogen for intracellular proliferation.