• Title/Summary/Keyword: Protein cleavage

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A Correspondence between Aging-related Reduction of Neprilysin and Elevation of Aβ-42 or γ-Secretase Activity in Transgenic Mice Expressing NSE-controlled APPsw or Human Mutant Presenilin-2

  • Lim Hwa-J.;Kim Yong-K.;Sheen Yhun-Y.
    • Biomolecules & Therapeutics
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    • v.14 no.2
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    • pp.106-109
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    • 2006
  • Neprilysin (Nep) is known to be important to degrade $A{\beta}$ derived from amyloid precursor protein (APP) by cleavage with $\beta-and\;\gamma$-secretases. In order to determine whether a correspondence between $A{\beta}-42/{\gamma}-secretase$ activity and Nep levels exists in postnatal aging of transgenic mice expressing either neuron-specific enolase (NSE)-controlled human mutant presenilin-2 (hPS2m) or APPsw alone, the levels of Nep expression and $A{\beta}-42/{\gamma}-secretase$ activity were examined age of 5, 12, and 20 months, respectively. The levels of Nep expression in both types of transgenic brains were decreased relative to those of control mice in a aging-related manner, while the level of $A{\beta}-42/{\gamma}-secretase$ activity was reversibly increased. Thus, changes in $A{\beta}-42$ may all reflect variation in amounts of Nep enzyme.

Shikonin Induced Apoptosis and Inhibited Angiogenesis on HSE Cells

  • Lee Soo-Jin;Kim Sung-Hoon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.5
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    • pp.1363-1369
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    • 2005
  • Previously we have shown that shikonin has strong anti-tumor activities via inducing apoptosis and suppressing metastasis on LLC cells in vivo and in vitro. Here we have investigated anti-angiogenic potential of shikonin and its possible mechanism of action in HSE cells. Shikonin inhibited the proliferation of HSE cells in a concentration-dependent manner. It was shown that this proliferation inhibition was caused by apoptosis induced by shikonin via BrdU incorporation and Western blotting analysis. Shikonin treatment was caused that decrease of activation of caspases and cleavage of PARP. And shikonin induced that the activation of mitogen-activated protein kinases (MAPKs), such as extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK) and p38. Moreover, shikonin showed anti-angiogenic activities inhibiting tube-like formation of HSE cells in vitro and vascular formation of LLC cells in vivo. These findings suggest that shikonin may a possible candidate not only anti-metastatic agent but also anti-angiogenic agent.

Activating Transcription Factor 3 is a Molecular Target for Apoptotic Effect of Silymarin in Human Colorectal Cancer Cells

  • Eo, Hyun Ji;Park, Gwang Hun;Jeong, Jin Boo
    • Korean Journal of Plant Resources
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    • v.29 no.3
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    • pp.281-288
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    • 2016
  • Apoptosis has been regarded as a therapeutic target because apoptosis is typically disturbed in human cancer. Silymarin found in the seeds of the milk thistle (Silybum marianum) has been reported to exert anti-cancer properties through apoptosis. This study was performed to investigate the molecular target for silymarin-mediated apoptosis in human colorectal cancer cells. Silymarin reduced the cell viability and induced an apoptosis in human colorectal cancer cells. ATF3 overexpression increased PARP cleavage by silymarin. Increased ATF3 expression in both protein and mRNA was observed in silymarin-treated cells. In addition, silymarin increased the luciferase activity of ATF3 promoter. Inhibition of JNK and IκK-α blocked silymarin-mediated ATF3 expression. The results suggest that silymarin induces apoptosis through JNK and IκKα-dependent ATF3 expression in human colorectal cancer cells.

Disruption of ATP binding destabilizes NPM/B23 and inhibits anti-apoptotic function

  • Choi, Joung-Woo;Lee, Sang-Bae;Ahn, Jee-Yin;Lee, Kyung-Hoon
    • BMB Reports
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    • v.41 no.12
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    • pp.840-845
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    • 2008
  • Nucleophosmin/B23, a major nucleolar phosphoprotein, is overexpressed in actively proliferating cells. In this study, we demonstrate that B23 exclusively localizes in the nucleolus, whereas ATP depletion results in the redistribution of B23 throughout the whole nucleus and destabilizes B23 via caspase-3 mediated cleavage. Interestingly, ATP binding precedes PI(3,4,5)P3 binding at lysine 263 and ATP binding mutants fail to restore the anti-apoptotic functions of B23 in PC12 cells. Thus, the ATP-B23 interaction is required for the stability of the B23 protein and regulates cell survival, confining B23 within the nucleolus in PC12 cells.

Functional Properties of Enzymatically Modified Egg Yolk Powder Produced by Phospholipase $A_2$ Treatment

  • Kim, Mi-Ra;Shim, Jae-Yong;Park, Ki-Hwan;Imm, Jee-Young
    • Food Science and Biotechnology
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    • v.17 no.6
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    • pp.1289-1293
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    • 2008
  • Fresh egg yolk (EY) was enzymatically modified using phospholipase $A_2$ ($PLA_2$) to produce an enzymatically modified-egg yolk powder (EM-EYP). The EM-EYP offered significantly higher emulsifying activity, emulsion stability, protein solubility, and mayonnaise stability than the control EYP. By employing $PLA_2$ in the enzymatic modification process, structural changes occurred in the phospholipids and lipoproteins of the yolk, and cleavage of apo-high density lipoprotein (HDL) components (Mw 105 kDa) was detected by sodium dodecyl sulfate-polyaerylamide gel electrophoresis (SDS-PAGE). Based on its functional properties, EM-EYP has great potential as a replacement for fresh EY in the production of processed food products such as mayonnaise.

Application of CRISPR-Cas9 gene editing for congenital heart disease

  • Seok, Heeyoung;Deng, Rui;Cowan, Douglas B.;Wang, Da-Zhi
    • Clinical and Experimental Pediatrics
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    • v.64 no.6
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    • pp.269-279
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    • 2021
  • Clustered regularly interspaced short palindromic repeats and CRISPR-associated protein 9 (CRISPR-Cas9) is an ancient prokaryotic defense system that precisely cuts foreign genomic DNA under the control of a small number of guide RNAs. The CRISPR-Cas9 system facilitates efficient double-stranded DNA cleavage that has been recently adopted for genome editing to create or correct inherited genetic mutations causing disease. Congenital heart disease (CHD) is generally caused by genetic mutations such as base substitutions, deletions, and insertions, which result in diverse developmental defects and remains a leading cause of birth defects. Pediatric CHD patients exhibit a spectrum of cardiac abnormalities such as septal defects, valvular defects, and abnormal chamber development. CHD onset occurs during the prenatal period and often results in early lethality during childhood. Because CRISPR-Cas9-based genome editing technology has gained considerable attention for its potential to prevent and treat diseases, we will review the CRISPR-Cas9 system as a genome editing tool and focus on its therapeutic application for CHD.

Substrate specificity of bacterial endoribonuclease toxins

  • Han, Yoontak;Lee, Eun-Jin
    • BMB Reports
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    • v.53 no.12
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    • pp.611-621
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    • 2020
  • Bacterial endoribonuclease toxins belong to a protein family that inhibits bacterial growth by degrading mRNA or rRNA sequences. The toxin genes are organized in pairs with its cognate antitoxins in the chromosome and thus the activities of the toxins are antagonized by antitoxin proteins or RNAs during active translation. In response to a variety of cellular stresses, the endoribonuclease toxins appear to be released from antitoxin molecules via proteolytic cleavage of antitoxin proteins or preferential degradation of antitoxin RNAs and cleave a diverse range of mRNA or rRNA sequences in a sequence-specific or codon-specific manner, resulting in various biological phenomena such as antibiotic tolerance and persister cell formation. Given that substrate specificity of each endoribonuclease toxin is determined by its structure and the composition of active site residues, we summarize the biology, structure, and substrate specificity of the updated bacterial endoribonuclease toxins.

Ircinin-1 from the Sponge Sarcotragus sp. Induces of Apoptosis in SK-MEL-2 Human Skin Cancer Cells

  • Choi, Hye-Joung;Yee, Su-Bog;Chung, Sang-Woon;Park, Sang-Eun;Choi, Yung-Hyun;Jung, Jee-Hyung;Kim, Nam-Deuk
    • Proceedings of the PSK Conference
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    • 2003.04a
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    • pp.230.1-230.1
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    • 2003
  • The marine sponge of the genus Petrosia sp. is known to contain unique metabolites such as furanoterpenoids. These furanoterpenoids have been reported to possess various bioactivities. We have shown previously that ircinin-1 induced cell cycle arrest and apoptosis in SK-MEL-2 human skin cancer cells dose- and time-dependently. In this study. we demonstrated that ircinin-1-induced apoptosis is a accompanied by cleavage of poly(ADP-ribose) polymerase protein and PLC-${\gamma}$1 degradation and release of cytochrome c from mitochondria to cytosol. (omitted)

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Sphingosine-1-Phosphate-Induced ERK Activation Protects Human Melanocytes from UVB-Induced Apoptosis

  • Kim, Dong-Seok;Kim, Sook-Young;Lee, Jai-Eun;Kwon, Sun-Bang;Sohn, Uy-Dong;Park, Kyoung-Chan
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.95.2-96
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    • 2003
  • Ultraviolet B (UVB) is known to induce apoptosis in human melanocytes. Here we show the cytoprotective effect of sphingosine-1-phosphate (S1P) against UVB-induced apoptosis. We also show that UVB-induced apoptosis of melanocytes is mediated by caspase-3 activation and poly(ADP-ribose) polymerase (PARP) cleavage, and that S1P prevents apoptosis by inhibiting this apoptotic pathway. We further investigated three major subfamilies of mitogen-activated protein (MAP) kinases and the Akt pathway after UVB irradiation. (omitted)

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Effects of Hyaluronidase during In Vitro Maturation on Maturation and Developmental Competence in Porcine Oocytes

  • Jeon, Ye-Eun;Hwangbo, Yong;Cheong, Hee-Tae;Park, Choon-Keun
    • Journal of Animal Reproduction and Biotechnology
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    • v.34 no.2
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    • pp.86-92
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    • 2019
  • The aim of this study was to investigate effects of hyaluronidase during IVM on oocyte maturation, oxidative stress status, expression of cumulus expansion-related (PTX, pentraxin; GJA1, gap junction protein alpha 1; PTGS2, prostaglandin-endoperoxide synthase 2) and fatty acid metabolism-related (FADS1, delta-6 desaturase; FADS2, delta-5 desaturase; PPARα, peroxisome proliferator-activated receptor-alpha) mRNA, and embryonic development of porcine oocytes. The cumulus-oocyte complexes (COCs) were incubated with 0.1 mg/mL hyaluronidase for 44 h. Cumulus expansion was measured at 22 h after maturation. At 44 h after maturation, nuclear maturation, intracellular glutathione (GSH) and reactive oxygen species (ROS) levels were measured. Gene expression in cumulus cells was analyzed using real time PCR. The cleavage rate and blastocyst formation were evaluated at Day 2 and 7 after insemination. In results, expansion of cumulus cells was suppressed by treatment of hyaluronidase at 22 h after maturation. Intracellular GSH level was reduced by hyaluronidase treatment (p < 0.05). On the other hand, hyaluronidase increased ROS levels in oocytes (p < 0.05). Only PTGS2 mRNA was enhanced in COCs by hyaluronidase (p < 0.05). Population of oocytes reached at metaphase II stage was higher in control group than hyaluronidase treated group (p < 0.05). Both of cleavage rate and blastocyst formation were higher in control group than hyaluronidase group (p < 0.05). Our present results showed that developmental competence of porcine oocytes could be reduce by hyaluronidase via inducing oxidative stress during maturation process and it might be associated with prostaglandin synthesis. Therefore, we suggest that suppression of cumulus expansion of COCs could induce oxidative stress and decrease nuclear maturation via reduction of GSH synthesis and it caused to decrease developmental competence of mammalian oocytes.