• Molecules and Cells
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• 제41권1호
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• pp.35-44
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• 2018

Mitochondria are responsible for supplying of most of the cell's energy via oxidative phosphorylation. However, mitochondria also can be deleterious for a cell because they are the primary source of reactive oxygen species, which are generated as a byproduct of respiration. Accumulation of mitochondrial and cellular oxidative damage leads to diverse pathologies. Thus, it is important to maintain a population of healthy and functional mitochondria for normal cellular metabolism. Eukaryotes have developed defense mechanisms to cope with aberrant mitochondria. Mitochondria autophagy (known as mitophagy) is thought to be one such process that selectively sequesters dysfunctional or excess mitochondria within double-membrane autophagosomes and carries them into lysosomes/vacuoles for degradation. The power of genetics and conservation of fundamental cellular processes among eukaryotes make yeast an excellent model for understanding the general mechanisms, regulation, and function of mitophagy. In budding yeast, a mitochondrial surface protein, Atg32, serves as a mitochondrial receptor for selective autophagy that interacts with Atg11, an adaptor protein for selective types of autophagy, and Atg8, a ubiquitin-like protein localized to the isolation membrane. Atg32 is regulated transcriptionally and post-translationally to control mitophagy. Moreover, because Atg32 is a mitophagy-specific protein, analysis of its deficient mutant enables investigation of the physiological roles of mitophagy. Here, we review recent progress in the understanding of the molecular mechanisms and functional importance of mitophagy in yeast at multiple levels.

• 생명과학회지
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• 제19권5호
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• pp.625-632
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• 2009

결과적으로 본 연구에서 서로 다른 두 집단(RTG, ATG)의 비교시 저항성 트레이닝 집단(RTG)보다 유산소 트레이닝 집단(ATG)에서 산화질소(NO) 농도가 더 높게 나타났으며, 이는 지속적인 유산소 형태의 트레이닝이 간헐적인 저항성 형태의 트레이닝 보다 더 많은 산화질소(NO)가 생성 된다는 것을 알 수 있었다. 또한 심박수(HR)와 혈압(BP), 평균동맵압(MAP)의 감소에도 저항성 트레이닝(RT)보다는 유산소 트레이닝(AT)이 효과적이라는 것을 알 수 있었다. 그러나 유산소 트레이닝(AT)에 비해 저항성 트레이닝(RT)에서 유의하진 않았지만 산화질소(NO) 농도가 증가된 것은 주목할 만한 결과이다. 이러한 결과로 볼 때, 단기간일 지라도 혈관이완 및 자율신경계 도움을 줄 수 있는 것은 유산소 트레이닝(AT) 임을 알 수 있었고 이는 일반적으로 운동을 선택할 시(근력과 근비대를 제외한 운동) 도움을 줄 수 있다고 사료된다. 또한 추후 연구에서는 12주 이상의 장기간의 트레이닝을 통해 저항성 트레이닝(RT)이 혈관이완의 직접적인 척도인 산화질소(NO) 농도에 관한 연구가 필요시 된다.

• BMB Reports
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• 제54권2호
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• pp.118-123
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• 2021

The bacterial effector protein RavZ from a pathogen can impair autophagy in the host by delipidating the mammalian autophagy-related gene 8 (mATG8)-phosphatidylethanolamine (PE) on autophagic membranes. In RavZ, the membrane-targeting (MT) domain is an essential function. However, the molecular mechanism of this domain in regulating the intracellular localization of RavZ in cells is unclear. In this study, we found that the fusion of the green fluorescent protein (GFP) to the MT domain of RavZ (GFP-MT) resulted in localization primarily to the cytosol and nucleus, whereas the GFP-fused duplicated-MT domain (GFP-2xMT) localized to Rab5- or Rab7-positive endosomes. Similarly, GFP fusion to the catalytic domain (CA) of RavZ (GFP-CA) resulted in localization primarily to the cytosol and nucleus, even in autophagy-induced cells. However, by adding the MT domain to GFP-CA (GFP-CA-MT), the cooperation of MT and CA led to localization on the Rab5-positive endosomal membranes in a wortmannin-sensitive manner under nutrient-rich conditions, and to autophagic membranes in autophagy-induced cells. In autophagic membranes, GFP-CA-MT delipidated overexpressed or endogenous mATG8-PE. Furthermore, GFP-CA△α3-MT, an α3 helix deletion within the CA domain, failed to localize to the endosomal or autophagic membranes and could not delipidate overexpressed mATG8-PE. Thus, the CA or MT domain alone is insufficient for stable membrane localization in cells, but the cooperation of MT and CA leads to localization to the endosomal and autophagic membranes. In autophagic membranes, the CA domain can delipidate mATG8-PE without requiring substrate recognition mediated by LC3-interacting region (LIR) motifs.

• 생명과학회지
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• 제19권7호
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• pp.968-975
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• 2009

본 연구에서는 8주의 유산소 및 저항성 트레이닝 그룹으로 나누고 그에 따른 트레이닝이 서로 다른 테스트를 하였을 때, 운동 특이성 효과(specific effect)와 전사효과(transferabilty)에 영향을 미치는 지를 연구하였다. 결론적으로 8주간의 유산소 및 저항성 트레이닝은 동일한 테스트를 통하여 운동의 특이성은 나타냈으나 서로 다른 테스트를 해 봄으로써 전사효과의 향상은 나타내지 못했다. 전사효과를 나타내지 못한 가장 큰 이유는 8주라는 기간이 중추신경과 근육의 적응하기에는 다소 짧은 기간이라 사료되며 추후의 연구에서는 트레이닝 기간등을 고려한 좀 더 세분화된 연구가 필요하다고 생각된다.

• Journal of Plant Biology
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• 제38권1호
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• pp.107-113
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• 1995

pRLYS1 containing intact rbcL gene of maize (Zea mays L. cv Golden X Bantam T-51; Zm-A) was digested with several restriction enzymes to construct subcones carrying promoter region of rbcL. The DNA fragments of 0.20, 0.19, 0.92 and 1.55 kb among the EcoRI digests, the EcoRI-DdeI digests, the AvaI digests and the EcoRI-BamHI digests of pRLYS1 were subcloned into pBluscriptSK＋and named pRLPS2, pRLPS3, pRLPS14 and pRLPS35, respectively. Four subclones contain the 1.92 kb portion from 136 nucleotide downstream to 1780 nucleotide upstream from the ATG initiation codon of rbcL gene. pRLPS2 (-29 to -229) and pRLPS3 (-239 to -420 from the ATG) were sequenced. When nucleotide sequence of Zm-A was compared with sequence of rbcL promoter region of a different cultivar of maize (Zea mays L. cv WFG TMS X BS7; Zm-B), the difference rate between two cultivars was 4.3%. The mean of sequence divergence between Zm-A and three grass species in the same tribe, Andropogoneae, in the upstream region from 29 to 420 of ATG was 1.8%, whereas between Zm-B and above-mentioned three species was 5.4%. Therefore, Zm-A seems to evolutionarily closer to three other species in Andropogoneae tribe than Zm-B is.

• 한국응용과학기술학회지
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• 제35권2호
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• pp.412-422
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• 2018

본 연구는 남자 대학생을 대상으로 12주간의 규칙적인 태권도 운동이 체구성, 체력, 뇌파활성 및 뇌신경성장인자(BDNF, IGF-1, NGF)에 미치는 영향을 규명하는데 목적이 있었다. 이를 위해 의학적 질환이 없는 대학생 24명을 대조그룹(CG), 유산소 트레이닝 그룹(ATG) 그리고 태권도 트레이닝 그룹(TTG)에 각각 8명씩 무선 배정하여 연구를 실시하였다. 12주 유산소 및 태권도 트레이닝은 주 3회 실시되었으며, 운동강도와 시간은 4주단위로 조정되었다. 뇌파활성 검사 및 채혈은 12주 유산소 및 태권도 트레이닝 전과 후 각각 실시되었으며, 그룹과 시기에 따른 체력요인 및 생화학성분에 대한 차이를 검증하기 위하여 채혈 시점을 반복 측정하는 이원변량분석(two-way repeated ANOVA)을 실시하였다. 이에 대한 연구결과는 다음과 같다. 12주간의 유산소 및 태권도 트레이닝은 신체구성과 뇌파활성에 영향을 미치지 못한 것으로 나타났다. 그러나 유산소 트레이닝과 태권도 트레이닝 모두 체력요소 중 평형성을 증가시키는 것으로 나타났으며(p<.05), 12주 유산소 트레이닝은 뇌신경성장인자인 BDNF를 증가시키는 것으로 나타났다(p<.05). 이상의 결과 12주 유산소 운동은 체력과 뇌신경영양인자에 긍정적인 효과가 있는 반면 태권도 운동은 뇌파 활성화 및 뇌신경영양인자에 영향을 미치지 못한 것으로 나타났다.

• Journal of Microbiology and Biotechnology
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• 제30권9호
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• pp.1412-1419
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• 2020

Human noroviruses (HuNoVs) are a leading cause of gastroenteritis outbreaks worldwide. However, the paucity of appropriate cell culture models for HuNoV replication has prevented developing effective anti-HuNoV therapies. In this study, first, the replication of the virus at various temperatures in different cells was compared, which showed that lowering the culture temperature from 37℃ significantly increased virus replication in Madin-Darby canine kidney (MDCK) cells. Second, the expression levels of autophagy-, immune-, and apoptosis-related genes at 30℃ and 37℃ were compared to explore factors affecting HuNoV replication. HuNoV cultured at 37℃ showed significantly increased autophagy-related genes (ATG5 and ATG7) and immune-related genes (IFNA, IFNB, ISG15, and NFKB) compared to mock. However, the virus cultured at 30℃ showed significantly decreased expression of autophagy-related genes (ATG5 and ATG7), but not significantly different major immune-related genes (IFNA, ISG15, and NFKB) compared to mock. Importantly, expression of the transcription factor FOXO1, which controls autophagy- and immune-related gene expression, was significantly lower at 30℃. Moreover, FOXO1 inhibition in temperature-optimized MDCK cells enhanced HuNoV replication, highlighting FOXO1 inhibition as an approach for successful virus replication. In the temperature-optimized cells, various HuNoV genotypes were successfully replicated, with GI.8 showing the highest replication levels followed by GII.1, GII.3, and GII.4. Furthermore, ultrastructural analysis of the infected cells revealed functional HuNoV replication at low temperature, with increased cellular apoptosis and decreased autophagic vacuoles. In conclusion, temperature-optimized MDCK cells can be used as a convenient culture model for HuNoV replication by inhibiting FOXO1 and providing adaptability to different genotypes.

• Asian Pacific Journal of Cancer Prevention
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• 제14권12호
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• pp.7537-7542
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• 2013

Background: Terpinen-4-ol, a monoterpene, is found as the main component of essential oil extracts from many plants. In this study apoptotic and autophagic types of cell death induced by terpinen-4-ol and associated mechanisms were investigated in human leukemic HL-60 cells. Materials and Methods: The cytotoxicity of human leukemic U937 and HL-60 cells was determined by MTT assay. Cytochrome c release, expression of Bax, Bcl-2, Bcl-xl and cleaved Bid were determined by Western blotting. Cell morphology was examined under a transmission electron microscope. LC3-I/II, ATG5 and Beclin-1 levels were detected by immunoblotting. Results: Terpinen-4-ol exhibited cytotoxicity to human leukemic HL-60 but not U937 cells. The apoptotic response to terpinen-4-ol in HL-60 cells was due to induction of cytochrome c release from mitochondria and cleavage of Bid protein after the stimulation of caspase-8. There was a slightly decrease of Bcl-xl protein level. The characteristic cell morphology of autophagic cell death was demonstrated with multiple autophagosomes in the cytoplasm. At the molecular level, the results from Western blot analysis showed that terpinen-4-ol significantly induced accumulation of LC3-I/II, ATG5 and Beclin-1, regulatory proteins required for autophagy in mammalian cells. Conclusions: Terpinen-4-ol induced-human leukemic HL-60 cell death was via both autophagy and apoptosis.

• Journal of Microbiology and Biotechnology
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• 제8권3호
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• pp.284-286
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• 1998

A ura5 gene encoding Orotate Phosphoribosyl Transferase (OPRTase) of Metarhizium anisopliae was cloned by PCR methods and sequenced. The sequenced ura 5 gene encodes a polypeptide of 234 amino acid residues. This deduced amino acid sequence showed high similarity to other fungi OPRTase and there was no intron sequence between ATG starting codon and TGA ending codon.

• Reproductive and Developmental Biology
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• 제37권2호
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• pp.65-73
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• 2013

The objective of this study was to examine the effects of high concentrations of glucose on porcine parthenotes developing in vitro. Addition of 55 mM glucose to the culture medium of embryos at the four-cell-stage significantly inhibited blastocyst formation, resulting in fewer cells in blastocyst-stage embryos and increased levels of apoptosis and autophagy compared to control. Quantitative reverse transcriptase (RT) PCR analysis revealed that the expression of pro-apoptotic genes (Caspase 3, Bax and Bak) and autophagy genes (Atg6 and Atg8/Lc3) were increased significantly by the addition of 55 mM glucose to the culture medium compared to control. MitoTracker Green fluorescence revealed a decrease in the overall mitochondrial mass compared to control. However, the addition of 55 mM glucose had no effect on mRNA expression of the nuclear DNA-encoded mitochondrial-related genes, cytochrome oxidase (Cox) 5a, Cox5b and Cox6b1. These results suggest that hyperglycemia reduced the mitochondrial content of porcine embryos developing in vitro and that this may hinder embryonic development to the blastocyst stage and embryo quality by increasing apoptosis and autophagy in these embryos.