• 제목/요약/키워드: biology major

검색결과 2,052건 처리시간 0.048초

The central regulator p62 between ubiquitin proteasome system and autophagy and its role in the mitophagy and Parkinson's disease

  • Shin, Woo Hyun;Park, Joon Hyung;Chung, Kwang Chul
    • BMB Reports
    • /
    • 제53권1호
    • /
    • pp.56-63
    • /
    • 2020
  • The ubiquitin-proteasome system (UPS) and autophagy are two major degradative pathways of proteins in eukaryotic cells. As about 30% of newly synthesized proteins are known to be misfolded under normal cell conditions, the precise and timely operation of the UPS and autophagy to remove them as well as their tightly controlled regulation, is so important for proper cell function and survival. In the UPS, target proteins are labeled by small proteins called ubiquitin, which are then transported to the proteasome complex for degradation. Alternatively, many greatly damaged proteins are believed to be delivered to the lysosome for autophagic degradation. Although these autophagy and UPS pathways have not been considered to be directly related, many recent studies proposed their close link and dynamic interconversion. In this review, we'll focus on the several regulatory molecules that function in both UPS and autophagy and their crosstalk. Among the proposed multiple modulators, we will take a closer look at the so-called main connector of UPS-autophagy regulation, p62. Last, the functional role of p62 in the mitophagy and its implication for the pathogenesis of Parkinson's disease, one of the major neurodegenerative diseases, will be briefly reviewed.

Protective Effect of EGCG Against Reactive Oxygen Species-induced Stress

  • Ha, Jung-Sun;Kim, Jeong-Hee
    • International Journal of Oral Biology
    • /
    • 제30권3호
    • /
    • pp.77-84
    • /
    • 2005
  • EGCG[(-)-epigallocatechin gallate], is a major component of green tea has been considered as a major antioxidant constituent. It has been considered as potential chemopreventive and chemotherapeutic agents. However, very little is known about the cellular actions by which EGCG mediates its therapeutic effects. Various aspects of antioxidant activity of EGCG were evaluated in this study. EGCG itself did not show significant cytotoxicity. Significant 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was observed in all ranges of concentration ($0.8-100{\mu}g/ml$) used in this study. Protective effect of EGCG against hydrogen peroxide induced cell death was observed. Relatively high lipid peroxidation inhibitory activity were detected ($IC_{50}$ was about $20{\mu}g/ml$). EGCG also dose-dependently enhanced the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in V79-4 cells. In concentrations of $100{\mu}g/ml$ of EGCG, activities of SOD, CAT and GPX were measured as 36.9 U/mg of protein, 22.9 U/mg of protein and 17.8 U/mg of protein, respectively. When these values were compared with those of the control groups (24.9 U/mg of protein, 14.9 U/mg of protein and 11.7 U/mg of protein), the relative increases were calculated as 48, 54 and 52%, respectively. Taken together, our findings suggest that EGCG can act as an antioxidant by scavenging radicals and enhancing antioxidant enzyme activities.

Flavonoids from Leaves and Exocarps of the Grape Kyoho

  • Park, Hye-Jeong;Cha, Hyeon-Cheol
    • Animal cells and systems
    • /
    • 제7권4호
    • /
    • pp.327-330
    • /
    • 2003
  • We analyzed and compared profiles of flavonols extracted from leaves and exocarps of the grape Kyoho by TLC, HPLC and UV spectrophotometry. In the exocarps, quercetin 3-O-glucoside was the main compound while isorhamnetin 3-O-glycoside (I) was present in minor amounts. In leaves, on the other hand, quercetin 3-O-glucoside and quercetin 3-O-glucoside-7-O-glucronide were the major compounds while isorhamnetin 3-O-glycoside (II) and kaempferol 3, 7-O-diglycoside were present in minor amounts.

Recent Advances in Molecular Basis of Lung Aging and Its Associated Diseases

  • Kang, Min-Jong
    • Tuberculosis and Respiratory Diseases
    • /
    • 제83권2호
    • /
    • pp.107-115
    • /
    • 2020
  • Aging is often viewed as a progressive decline in fitness due to cumulative deleterious alterations of biological functions in the living system. Recently, our understanding of the molecular mechanisms underlying aging biology has significantly advanced. Interestingly, many of the pivotal molecular features of aging biology are also found to contribute to the pathogenesis of chronic lung disorders such as chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis, for which advanced age is the most crucial risk factor. Thus, an enhanced understanding of how molecular features of aging biology are intertwined with the pathobiology of these aging-related lung disorders has paramount significance and may provide an opportunity for the development of novel therapeutics for these major unmet medical needs. To serve the purpose of integrating molecular understanding of aging biology with pulmonary medicine, in this review, recent findings obtained from the studies of aging-associated lung disorders are summarized and interpreted through the perspective of molecular biology of aging.

Morphological characteristics of major airborne pollen in Korea peninsula

  • Moon, Hye-Kyoung;Kong, Min-Jung;Song, Jun-Ho;Kim, Sun-Yu;Kim, Jin-Suk;Jung, Eun-Hee;Park, Chan-Ho;Lee, Byoung-Yoon;Hong, Suk-Pyo
    • Journal of Species Research
    • /
    • 제4권2호
    • /
    • pp.159-168
    • /
    • 2015
  • Although airborne pollen is invisible to the eye, it has been known as a major source to respiratory allergic reactions. For this reason, airborne pollen is monitoring in many countries to predict pollen concentration based on locality and season. However, the morphological characteristics of airborne pollen and their potential tendency as an allergen are still obscure. In the present study, we selected 52 airborne pollen samples based on previously reported data and investigated their detail pollen characteristics using LM and SEM. Major airborne pollen in Korea has sorted in 19 families (most angiosperms except four gymnosperm families), and all pollen grains are small to medium in size ($P=17.34-49.86{\mu}m$) apart from the bisaccate pollen grains of Pinaceae ($P=46.49-106.20{\mu}m$). The aperture number and shape vary from sulcate to polyporate. While the inaperture pollen has found only in gymnosperm (Cupressaceae and Taxaceae), triporate or polyporate is common pollen type in angiosperm. The sexine ornamentations could divide into several types, but the most sculpturing types are inconspicuous like psilate, rugulate and granulate. Reticulate pollen grains as a semitectum have occurred the species of genera Platanus and Fraxinus only. To estimate the possible relationships between pollen features and allergen, the results are discussed in botanical context.

성장호르몬 방출인자를 발현하는 형질전환 생쥐에서 소변분석 (Urine Analysis in Transgenic Mice Expressing the Growth Hormone-releasing Factor)

  • Cho, Byung-Nam;Jung, Hoi-Kyung;Yoon, Yong-Dal;Mayo, Kelly-E
    • 한국발생생물학회지:발생과생식
    • /
    • 제6권1호
    • /
    • pp.31-35
    • /
    • 2002
  • 생쥐에서 페르몬으로 알려진 소수성의 분자와 결합하는 major urinary proteins(MUPs)는 부분적으로 성장 호르몬(GH)의 조절을 받는다. 본 연구에서는 MT-GRF로 형질전환되어 성장호르몬이 증가된 생쥐에서 MUP의 발현을 조사하였다. 이 MT-GRF로 형질전환된 생쥐의 소변에서 MUP이 대조군보다 심하게 저하되어 나타났고, 암컷보다 수컷에서 더 저하되어 나타났다. 또한 MT-GRF를 근육에 주사한 생쥐에서도 MUP는 저하되어 나타났다. 부가하여, MT-GRF로 형질전환시킨 생쥐의 소변에서 전기영동상에서 albumin과 동일하게 이동하는 고분자의 단백질이 다량으로 관찰되었는데 신장의 사구체 여과가 손상되었음을 암시하고 있다. 이 혈장 단백질의 손실도 암컷보다 수컷에서 심하게 나타났다. 결과적으로 GRF의 과다생성은 성별에 차별화된 영향을 미치면서 GH로 형질전환된 동물모델에서 관찰되는 MUP의 발현과 사구체 기능의 변화를 동일하게 유발하고 있었다.

  • PDF