• Journal of Microbiology and Biotechnology
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• 제25권2호
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• pp.234-237
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• 2015

In this study, we developed lysosome-alginate beads for application as an oral drug delivery system (ODDS). The beads harboring lysosomes, which have antimicrobial activity, and various concentrations of alginate were characterized and optimized. For application as an ODDS, pH-dependent lysosome-alginate beads were generated, and the level of lysosome release was investigated by using antimicrobial tests. At low pH, lysosomes were not released from the lysosome-alginate beads; however, at neutral pH, similar to the pH in the intestine, lysosome release was confirmed, as determined by a high antimicrobial activity. This study shows the potential of such an ODDS for the in vivo treatment of infection with pathogens.

• Molecules and Cells
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• 제41권1호
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• pp.45-49
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• 2018

Autophagy is a lysosome-dependent degradation process that is essential for maintaining cellular homeostasis. In recent years, more studies have focused on the late stages of autophagy. Our group discovered and studied the terminal step of autophagy, namely autophagic lysosome reformation (ALR). ALR is the process that regenerates functional lysosomes from autolysosomes, thus maintaining lysosome homeostasis. ALR involves clathrin-mediated membrane budding from autolysosomes, elongation of membrane tubules along microtubules with the pulling force provided by the motor protein KIF5B, proto-lysosome scission by dynamin 2, and finally maturation of proto-lysosomes to functional lysosomes. In this review, we will summarize progress in unveiling the molecular mechanisms underlying ALR and its potential pathophysiological roles.

• Molecules and Cells
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• 제43권8호
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• pp.705-717
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• 2020

While the growth factors like insulin initiate a signaling cascade to induce conformational changes in the mechanistic target of rapamycin complex 1 (mTORC1), amino acids cause the complex to localize to the site of activation, the lysosome. The precise mechanism of how mTORC1 moves in and out of the lysosome is yet to be elucidated in detail. Here we report that microtubules and the motor protein KIF11 are required for the proper dissociation of mTORC1 from the lysosome upon amino acid scarcity. When microtubules are disrupted or KIF11 is knocked down, we observe that mTORC1 localizes to the lysosome even in the amino acid-starved situation where it should be dispersed in the cytosol, causing an elevated mTORC1 activity. Moreover, in the mechanistic perspective, we discover that mTORC1 interacts with KIF11 on the motor domain of KIF11, enabling the complex to move out of the lysosome along microtubules. Our results suggest not only a novel way of the regulation regarding amino acid availability for mTORC1, but also a new role of KIF11 and microtubules in mTOR signaling.

• 미생물학회지
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• 제32권4호
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• pp.280-284
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• 1994

공생 아메바에서 리소솜과 공생낭 간에 융합이 저해되는 이유로서는 먼저 이들 공생낭의 막에 어떤 특별한 인자가 존재하여 융합을 저해하거나 또는 융합 과정에 필수적인 어떤 요소가 이들 공생막에는 부족하여 융합이 일어나지 않는다고 유추해 볼 수 있다. 단일 클론 항체를 추적물질로 사용하여 이들 인자나 구성요소를 알아내는 과정에서, lipopolysaccharides가 공생 박테리아에 의하여 생산되어 공생낭의 막에 삽입된다는 것을 확인하였으며 이들이 공생막상에서도 세포질 방향으로 노출되어 있다는 것을 알아내었다. 따라서 이들 lipopolysaccharides가 리소솜과 공생낭간의 융합 저해에 간여하는 가를 알아보기 위하여 이들에 대한 단일 크론 항체를 공생 아메자의 세포질에 미세주사하여 보았다. 주사된 아메바에서는 공생낭과 리소솜간의 융합이 일어나는 것으로 미루어 보아, 아마도 lipopolysaccharides는 융합저해 요소 중의 하나로 사료되어 진다.

• Animal cells and systems
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• 제4권2호
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• pp.165-171
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• 2000

Ubiquitinated proteins in lysosomes were characterized by using two monoclonal antibodies (mAbs): LYS8-1, a mAb to lysosomal proteins, and NYA124, a mAb to ubiquitin. LYS8-1 stained lysosome-like vesicles in immunofluorescence microscopy of Amoeba proteus and Acanthamoeba castellanii. In immunoblotting, LYS8-1's antigens (LYS proteins) were detected as 68-kDa and 77-kDa proteins in A. proteus, and as 30-kDa and 39-kDa proteins in A. castellanii. In immunoprecipitation of A. castellanii, at least four distinct LYS proteins, LVS35p, LyS39p, LyS42p, and LYS46p, were detected and accumulated upon inhibition of lysosome functions but not upon that of 26S proteasome functions. They were all found to be ubiquitinated, and were recovered in the lysosome fractions in subcellular fractionation experiments. In chemical fractionation analyses, LYS35p and LYS39p were demonstrated to be peripherally associated with lysosome membrane, while LYS42p and LYS46p tightly bound to the membrane. These results suggest that the LYS proteins become associated to lysosomal membrane upon ubiquitination.

• Journal of Applied Biological Chemistry
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• 제65권2호
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• pp.93-99
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• 2022

Lysosome organelle extract (LOE) was derived from egg whites. The lysosome is an intracellular organelle that contains several hydrolysis enzymes. Previous studies have reported that LOE performs important functions, such as melanin de-colorization and anti-melanin production in B16F10 melanoma cells. However, its principal molecular and cellular mechanisms have not been elucidated till date. In non-cytotoxic conditions, LOE significantly inhibited α-MSH induced melanin synthesis of murine B16F10 cells. The anti-melanogenic activity of LOE was mediated by suppressing the mRNA expression of tyrosinase enzyme, tyrosinase related protein-1/2 (TRP-1/2), and microphthalmia-associated transcription factor (MITF) genes. By performing western blot analysis, we found that LOE significantly attenuated melanogenesis. In this case, LOE helped in increasing extracellular receptor kinase (ERK) phosphorylation in α-MSH induced B16F10 cells. Furthermore, MITF is found to be a key regulatory transcription factor in melanin synthesis; it was down-regulated by LOE through ERK phosphorylation. In this experiment, PD98059 (MEK inhibitor) was used to check whether LOE directly regulated the activity of ERK. Although LOE exerted inhibitory effect on melanin synthesis, we could not observe this effect in PD98059-treated α-MSH induced B16F10. These results strongly indicate that LOE is related to ERK activation and MITF degradation in anti-skin pigmentation. Hence, LOE should be utilized as a whitening agent of skin in the near future.

• Molecules and Cells
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• 제45권9호
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• pp.649-659
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• 2022

A long-term energy nutritional imbalance fundamentally causes the development of obesity and associated fat accumulation. Lysosomes, as nutrient-sensing and lipophagy centers, critically control cellular lipid catabolism in response to nutrient deprivation. However, whether lysosome activity is directly involved in nutrient-induced fat accumulation remains unclear. In this study, worm fat accumulation was induced by 1 mM glucose or 0.02 mM palmitic acid supplementation. Along with the elevation of fat accumulation, lysosomal number and acidification were also increased, suggesting that lysosome activity might be correlated with nutrient-induced fat deposition in Caenorhabditis elegans. Furthermore, treatments with the lysosomal inhibitors chloroquine and leupeptin significantly reduced basal and nutrient-induced fat accumulation in C. elegans. The knockdown of hlh-30, which is a critical gene in lysosomal biogenesis, also resulted in worm fat loss. Finally, the mutation of aak-2, daf-15, and rsks-1 showed that mTORC1 (mechanistic target of rapamycin complex-1) signaling mediated the effects of lysosomes on basal and nutrient-induced fat accumulation in C. elegans. Overall, this study reveals the previously undescribed role of lysosomes in overnutrition sensing, suggesting a new strategy for controlling body fat accumulation.

• Environmental Analysis Health and Toxicology
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• 제31권
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• pp.9.1-9.5
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• 2016

Objectives There have been developed to use targeting ability for antimicrobial, anticancerous, gene therapy and cosmetics through analysis of various membrane proteins isolated from cell organelles. Methods It was examined about the lysosomal membrane protein extracted from lysosome isolated from HeLa cell treated by 100 ppm melanin for 24 hours in order to find associated with targeting ability to melanin using by 2-dimensional electrophoresis. Results The result showed 14 up-regulated (1.5-fold) and 13 down-regulated (2.0-fold) spots in relation to melanin exposure. Conclusions It has been found that lysosomal membrane proteins are associated with melanin to decolorize and quantity through cellular activation of lysosome.

• BMB Reports
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• 제48권3호
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• pp.129-130
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• 2015

Autophagy is a tightly regulated lysosome-mediated catabolic process in eukaryotes that maintains cellular homeostasis. A distinguishable feature of autophagy is the formation of double- membrane structures, autophagosome, which envelopes the intracellular cargoes and finally degrades them by fusion with lysosomes. So far, many structures of Atg proteins working on the autophagosome formation have been reported, however those involved in autophagosome maturation, a fusion with lysosome, are relatively unknown. One of the molecules in autophagosome maturation, TECPR1, has been identified and recently, structural studies on both ATG5-TECPR1 and ATG5-ATG16L1 complexes revealed that TECPR1 and ATG16L1 share the same binding site on ATG5. These results, in combination with supporting biochemical and cellular biological data, provide an insight into a model for swapping ATG5 partners for autophagosome maturation.

• 한국동물학회지
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• 제21권3호
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• pp.87-102
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• 1978

수은이 붕어(Carassius carassius L.)의 간, 신장 아가미에 미치는 영향을 규명하기 위하여 붕어를 1 ppm, 2.5 ppm 농도의 $HgCl_2$에 노출시킨 후 전자현미경을 사용하여 그들의 미세구조 변화에 대한 연구를 수행한 바 다음과 같은 결과를 얻었다. 1. 수은에 처리된 간세포에서는 lysosome이 증가하였으며 결정상의 구조물들을 포함한 원형의 lysosome과 히ㅛ\ulcorner두과립이나 mitochondria를 탐식한 lysosome의 2가지 형태가 관찰되었고 mitochondria는 팽대되어 내부 기질의 전자밀도가 감소되었으며 핵에서는 인의 분리현상이 관찰되었다. 2. 신장의 변화로서는 신사구체 기저막의 비후와 기부선회소관에서는 공포들의 증가와 cytoplasmic body들이 출현하였으며 공포형성은 mitochondria와 연관되어 일어났다. 또한 2.5 ppm에서는 핵의 위축이 관찰되었다. 3. Gill lamella의 상피세포에서는 대, 소형의 lysosome이 증가했으며 lamella의 막에 fuzzy한 구조가 관찰되었다. 4. 본 실험에서 관찰된 결과로써 수은에 의해 초래된 세포의 미세구조의 변화는 세포의 해독과정을 활성화시키며 energy대사과정을 손상시키는 것으로 생각된다.