• 제목/요약/키워드: Atg5

검색결과 121건 처리시간 0.023초

Raloxifene Induces Autophagy-Dependent Cell Death in Breast Cancer Cells via the Activation of AMP-Activated Protein Kinase

  • Kim, Dong Eun;Kim, Yunha;Cho, Dong-Hyung;Jeong, Seong-Yun;Kim, Sung-Bae;Suh, Nayoung;Lee, Jung Shin;Choi, Eun Kyung;Koh, Jae-Young;Hwang, Jung Jin;Kim, Choung-Soo
    • Molecules and Cells
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    • 제38권2호
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    • pp.138-144
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    • 2015
  • Raloxifene is a selective estrogen receptor modulator (SERM) that binds to the estrogen receptor (ER), and exhibits potent anti-tumor and autophagy-inducing effects in breast cancer cells. However, the mechanism of raloxifene-induced cell death and autophagy is not well-established. So, we analyzed mechanism underlying death and autophagy induced by raloxifene in MCF-7 breast cancer cells. Treatment with raloxifene significantly induced death in MCF-7 cells. Raloxifene accumulated GFP-LC3 puncta and increased the level of autophagic marker proteins, such as LC3-II, BECN1, and ATG12-ATG5 conjugates, indicating activated autophagy. Raloxifene also increased autophagic flux indicators, the cleavage of GFP from GFP-LC3 and only red fluorescence-positive puncta in mRFP-GFP-LC3-expressing cells. An autophagy inhibitor, 3-methyladenine (3-MA), suppressed the level of LC3-II and blocked the formation of GFP-LC3 puncta. Moreover, siRNA targeting BECN1 markedly reversed cell death and the level of LC3-II increased by raloxifene. Besides, raloxifene-induced cell death was not related to cleavage of caspases-7, -9, and PARP. These results indicate that raloxifene activates autophagy-dependent cell death but not apoptosis. Interestingly, raloxifene decreased the level of intracellular adenosine triphosphate (ATP) and activated the AMPK/ULK1 pathway. However it was not suppressed the AKT/mTOR pathway. Addition of ATP decreased the phosphorylation of AMPK as well as the accumulation of LC3-II, finally attenuating raloxifene-induced cell death. Our current study demonstrates that raloxifene induces autophagy via the activation of AMPK by sensing decreases in ATP, and that the overactivation of autophagy promotes cell death and thereby mediates the anti-cancer effects of raloxifene in breast cancer cells.

Erwinia carotovora subsp. carotovora LY34에서 pelCI 유전자 클로닝 (Cloning and Sequencing of the pelCl Gene Encoding Pectate Lyase of Erwinia carotovora subsp. carotovora LY34)

  • 임선택;박용우;윤한대
    • Applied Biological Chemistry
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    • 제40권5호
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    • pp.380-387
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    • 1997
  • Pectate lyase isoenzymes을 분비하는 Erwinia carotovorn subsp. carotovora LY34는 식물조직을 연화시키는 연부균이다. 이 균주로부터 게놈 DNA를 분리하여 Sau3Al 제한효소로 부분 절단한 다음 pBluescript $SK^+$ 벡터에 클로닝하여 pectate Iyase를 분비하는 클론을 분리하였다 분리 결과 4.2 kb크기의 DNA 단편을 가지고 있었으며 이를 다시 재클로닝하여 3.1 kb크기의 pelCI유전자를 함유하는 pLYPA100을 구하였다. 이 유전자의 DNA 염기서열을 분석한 결과 374 개의 아미노산을 구성하는 1,122 bp의 ORF를 확인하였다. 시작코돈과 종결코돈은 ATG와 TAA였으며 초기 서열 22개의 아미노산으로 구성된 전형적인 원핵세포의 signal peptide가 존재하였다. PeICI의 단백질 염기서열을 다른 단백질과 유사성을 분석한 결과 Erwinia carotovera subsp. carotovora Er 균주의 PelIII, Erwinia carotevora subsp. carotovora SCR193 균주의 PeIC 및 Erwinia caretovora subsp. atroseptica C18 균주의 Pel3과 유사하였으며 PLbc family에 속하였다. PeICI의 분자량은 40,507, pI는 7.60으로 계산되었다.

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열다한소탕(熱多寒少湯) 가감방(加減方)의 자가탐식(自家貪食) 유도 활성과 관련 단백질 탐색 (Autophagy inducing Effect of modified Yeoldahanso-tang and its related Proteins in SH-SY5Y cells)

  • 김희주;배나영;장문희;양현옥;안택원
    • 사상체질의학회지
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    • 제25권3호
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    • pp.208-217
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    • 2013
  • Objectives Modified Yeolda-Hanso tang (MYH) is a traditional herbal formula in Korea for various diseases. MYH is containing the 10 herbs : Pueraria lobata (Willd.) Ohwi, Angelica tenuissima Nakai, Scutellaria baicalensis Georgi, Platycodon grandiflorum (Jacq), Angelicae Dahurica, Cimicifuga heracleifolia Kom, Raphanus sativa L., Polygala tenuifolia (Willd), Acorus gramineus Soland and Dimocarpus longan Lour. The 10 herbs is constituted as a ratio of the 6:4:2:1:2:2:2:4:6:6. We investigated neuroprotective effects of MYH on human neuroblastoma SH-SY5Y cells and evaluated the ability of MYH to prevent and treat for neurodegenerative diseases such as Parkinson's disease via basal autophagy enhancement. Methods Pharmacological induction of Autophagy by MYH in SH-SY5Y cells: Induction of autophagy by MYH in human neuroblastoma SH-SY5Y cells was carreid out by immunoblot analysis with several autophagy markers. SH-SY5Y cells were treated with MYH at the concentration of 400 and $800{\mu}g/ml$ for 24 hr. Specifically, the autophagosome proteins LC3 II and Atg5 levels were increased and autophagy pathway related proteins such as beclin-1, PI3 Kinase class III protein, ULK1, mTOR and AMPK were activated. Conclusions MYH can enhance the induction of autophagy through key regulator AMPK, mTOR, and Beclin-1 and it should be considered as a possible candidate of neuroprotective agents for such as Parkinson's disease.

BmNPV의 p10 유전자를 이용한 새로운 전이벡터 개발 (Construction of the Novel Baculovirus Transfer Vector Using the p10 Gene of BmNPV)

  • 강석우;진병래
    • 한국잠사곤충학회지
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    • 제39권2호
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    • pp.180-185
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    • 1997
  • To develope the novel baculovirus transfer vector, the p10 gene was cloned from the Bombyx mori nuclear polygedrosis virus (BmNPV) vB2 strain isolated from the B. mori larvae of sericultural farms. The novel transfer vector was constructed by using the p10 gene of BmNPV vB2 strain was 210 bp. The TAAG sequence at the -71 bp of upstream from translation initiator ATG and two polyadenylation signal site at the downstream from terminator TAA were also detected in the p10 gene. The 5' and 3' flanking region of the p10 gene amplified by PCR was cloned into pBluescriptII SK(+) and then transfer vector pBm10 was construceted. The 7.9 kb pBm10 was analysed by restriction enzymes and the map was confirmed. In order to determine the expression of foreign gene of pBm10, $\beta$-galactosidase gene was inserted in the SmaI site of foreign gene cloning site of pBm10. The pBm10 containing $\beta$-galactosidase gene was cotranfected wth genomic DNA of BmNPV vB2 into BmN-4 cells. The recombinant baculovirus expressing $\beta$-galactosidase was also produced polygedra in the infected cells. The results indicated that pBm10 is functional, suggesting that in the baculovirus expression vector system, the recombinant virus produced by pBm10 was effective by oral infection for the producing recombinant proteins in in vivo expression.

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Cloning, characterization and expression of glucoamylase gene from ectomycorrhizal basidomycete, Tricholoma matsutake

  • Wan, Jianing;Yi, Ruirong;Li, Yan;Kinjo, Yukiko;Sadashima, Aki;Terashita, Takao;Yamanaka, Katsuji;Aimi, Tadanori
    • 한국버섯학회지
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    • 제9권2호
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    • pp.53-58
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    • 2011
  • In order to confirm the presence of putative glucoamylase gene in Tricholoma matsutake genome, the genomic DNA was prepared from T. matsutake NBRC30773 strain and was used as template to clone the glucoamylases gene (TmGlu1). We obtained the nucleotide sequence of TmGlu1 and its franking region. The coding region (from ATG to stop codon) is 2,186 bp. The locations of exons and introns were determined from the nucleotide sequences of 3'- and 5'-RACE PCR and RT-PCR products. On the other hand, to investigate the relationship between composition of medium and glucoamylase expression, we checked the expression level of glucoamylase gene by realtime reverse transcription PCR and measurement of glucoamylase enzyme activity. It was found that enzyme activity of glucoamylase was very low in different medium. Expression of glucoamylases gene appeared to not be affected by different carbon source.

Sequencing of the RSDA Gene Encoding Raw Starch-Digesting $\alpha$-Amylase of Bacillus circulans F-2: Identification of Possible Two Domains for Raw Substrate-Adsorption and Substrate-Hydrolysis

  • Kim, Cheorl-Ho
    • Journal of Microbiology and Biotechnology
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    • 제2권1호
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    • pp.56-65
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    • 1992
  • The complete nucleotide sequence of the Bacillus circulans F-2 RSDA gene, coding for raw starch digesting a-amylase (RSDA), has been determined. The RSDA structure gene consists of an open reading frame of 2508 bp. Six bp upstream of the translational start codon of the RSDA is a typical gram-positive Shine-Dalgarno sequence and the RSDA encodes a preprotein of 836 amino acids with an Mr of 96, 727. The gene was expressed from its own regulatory region in E. coli and two putative consensus promoter sequences were identified upstream of a ribosome binding site and an ATG start codon. Confirmation of the nucleotide sequence was obtained and the signal peptide cleavage site was identified by comparing the predicted amino acid sequence with that derived by N-terminal analysis of the purified RSDA. The deduced N-terminal region of the RSDA conforms to the general pattern for the signal peptides of secreted prokaryotic proteins. The complete amino acid sequence was deduced and homology with other enzymes was compared. The results suggested that the Thr-Ser-rich hinge region and the non-catalytic domain are necessary for efficient adsorption onto raw substrates, and the catalytic domain (60 kDa) is necessary for the hydrolysis of substrates, as suggested in previous studies (8, 9).

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Light Regulation of rbcL Transcript and Protein-binding Region on rbcL Promoter in Maize

  • Lee, Jae-Seon;Sim, Woong-Seop
    • Journal of Plant Biology
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    • 제39권4호
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    • pp.279-286
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    • 1996
  • To know the changes of rbcL mRNA level by illumination, Northern hybridization analysis was performed with maize (Zea mays L.cv. Golden X Bantam). The average level of rbcL. mRNA in the light-grown shoots was 3.1 times higher than that of the dark-grown shoots after 6 to 10 growth days. The maximum difference of rbcL mRNA level between the dark-grown and the light-grown shoots was 5.1 folds. These results indicate that accumulation of rbcL mRNAin maize shoots is induced by light. Since the transcriptional DNA binding proteins and their cognate promoter elements, we carried out gel-retardation assays to elucidate the specific binding proteins on the rbcL promoter. It was found that plastid proteins of light-grown shoots bound to the R2 DNA fragment (-33 to -229) and R3 DNA fragment (-230 to -418 from ATG) of the rbcL promoter. From the results of competitive binding assays and heat or protease treatments, it was demonstrated that the bindings were sequence-specific DNA-protein interactions. Therefore, it could be concluded that the rbcL promoter region has at least two specific recognition sites for plastid proteins.

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Differential Sensitivity of Wild-Type and BRAF-Mutated Cells to Combined BRAF and Autophagy Inhibition

  • Yeom, Hojin;Hwang, Sung-Hee;Han, Byeal-I;Lee, Michael
    • Biomolecules & Therapeutics
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    • 제29권4호
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    • pp.434-444
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    • 2021
  • BRAF inhibitors are insufficient monotherapies for BRAF-mutated cancer; therefore, we investigated which inhibitory pathway would yield the most effective therapeutic approach when targeted in combination with BRAF inhibition. The oncogenic BRAF inhibitor, PLX4720, increased basal autophagic flux in BRAF-mutated cells compared to wild-type (WT) BRAF cells. Interestingly, early autophagy inhibition improved the effectiveness of PLX4720 regardless of BRAF mutation, whereas late autophagy inhibition did not. Although ATG5 knockout led to PLX4720 resistance in both WT and BRAF-mutated cells, the MEK inhibitor trametinib exhibited a synergistic effect on PLX4720 sensitivity in WT BRAF cells but not in BRAF-mutated cells. Conversely, the prolonged inhibition of endoplasmic reticulum (ER) stress reduced basal autophagy in BRAF-mutated cells, thereby increasing PLX4720 sensitivity. Taken together, our results suggest that the combined inhibition of ER stress and BRAF may simultaneously suppress both pro-survival ER stress and autophagy, and may therefore be suitable for treatment of BRAF-mutated tumors whose autophagy is increased by chronic ER stress. Similarly, for WT BRAF tumors, therapies targeting MEK signaling may be a more effective treatment strategy. Together, this study presents a rational combination treatment strategy to improve the efficacy of BRAF inhibitors depending on BRAF mutation status.

Anti-inflammatory effects of N-cyclooctyl-5-methylthiazol-2-amine hydrobromide on lipopolysaccharide-induced inflammatory response through attenuation of NLRP3 activation in microglial cells

  • Kim, Eun-A;Hwang, Kyouk;Kim, Ji-Eun;Ahn, Jee-Yin;Choi, Soo Young;Yang, Seung-Ju;Cho, Sung-Woo
    • BMB Reports
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    • 제54권11호
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    • pp.557-562
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    • 2021
  • Microglial activation is closely associated with neuroinflammatory pathologies. The nucleotide-binding and oligomerization domain-like receptor containing a pyrin domain 3 (NLRP3) inflammasomes are highly organized intracellular sensors of neuronal alarm signaling. NLRP3 inflammasomes activate nuclear factor kappa-B (NF-κB) and reactive oxygen species (ROS), which induce inflammatory responses. Moreover, NLRP3 dysfunction is a common feature of chronic inflammatory diseases. The present study investigated the effect of a novel thiazol derivative, N-cyclooctyl-5-methylthiazol-2-amine hydrobromide (KHG26700), on inflammatory responses in lipopolysaccharide (LPS)-treated BV-2 microglial cells. KHG26700 significantly attenuated the expression of several pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, and interleukin-6, in these cells, as well as the LPS-induced increases in NLRP3, NF-κB, and phospho-IkBα levels. KHG26700 also suppressed the LPS-induced increases in protein levels of autophagy protein 5 (ATG5), microtubule-associated protein 1 light chain 3 (LC3), and beclin-1, as well as downregulating the LPS-enhanced levels of ROS, lipid peroxidation, and nitric oxide. These results suggest that the anti-inflammatory effects of KHG26700 may be due, at least in part, to the regulation of the NLRP3-mediated signaling pathway during microglial activation.

재조합 Saccharomyces cerevisiae로부터 인체 리포코틴-I의 분비 생산 및 정제 (Production and Purification of Human Lipocortin-I Secreted by Recombinant Saccharomyces cerevisiae)

  • 김병문;정봉현
    • KSBB Journal
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    • 제10권3호
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    • pp.343-348
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    • 1995
  • LeI은 스테로이드를 통울에 투여하였을 때 분비가 촉진되어 항염증성 효과를 나타내는 calcium 의 존성 phospholipid 결합 단백질이다. S. cerevisiae는 대장균과 통물세포의 장점을 모두 가지고 있으므로 동물세포 유래의 이종 단백질의 분비 생산에 많이 이용되고 있다. 본 연구에서는 GAL10 promoter­p ppL-LCI유전자 LCI terminator로 구성된 pYGLPT5 로 LCI을 S. cerevisiae SEY2102에서 발현 분비시키고 각 분획으로 나누어 LCI양을 비교한 결과 protoplast 68.6 %. periplasmic 24 %, culture supernatant 7.4%로 분포하였다. pYGLPT5로 형질전환된 S. cereviswe 2102를 유가 배양한 결과, 최종적인 LCI의 생산량은 약 $500mg/\ell$ 였다. LCI은 N 말단 부근에 $CA^{++}$ 결합부위가 있으므로 이를 이용하여 hydroxylapatite column chromatography로 정 제하 였다. 배지로 분비된 34kDa LCI을 ultrafiltration 과 hydroxylapatite column chromatography 의 두 단계로 순도 99% 이상으로 정제할 수 있었다.

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