183 research outputs found

    SUMOylation of xeroderma pigmentosum group C protein regulates DNA damage recognition during nucleotide excision repair

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    The xeroderma pigmentosum group C (XPC) protein complex is a key factor that detects DNA damage and initiates nucleotide excision repair (NER) in mammalian cells. Although biochemical and structural studies have elucidated the interaction of XPC with damaged DNA, the mechanism of its regulation in vivo remains to be understood in more details. Here, we show that the XPC protein undergoes modification by small ubiquitin-related modifier (SUMO) proteins and the lack of this modification compromises the repair of UV-induced DNA photolesions. In the absence of SUMOylation, XPC is normally recruited to the sites with photolesions, but then immobilized profoundly by the UV-damaged DNA-binding protein (UV-DDB) complex. Since the absence of UV-DDB alleviates the NER defect caused by impaired SUMOylation of XPC, we propose that this modification is critical for functional interactions of XPC with UV-DDB, which facilitate the efficient damage handover between the two damage recognition factors and subsequent initiation of NER

    Developing Simultaneous Brain Wave Measurement System in Human and Dog Communication

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    This paper proposes a measurement system for simultaneous measuring brain waves of human and cenine. The system consists of a headset for human brain wave, a headset for dog brain wave and video camera. The headset for adog brain wave measurement is specially developed by modifying human headset. The fabric cover attached with electrodes is fixed to a dog\u27s head with Velcro. The ears of a dog can extend naturally from holes of the fabric cover, which made a longer time experiment possible. The proposed system does not need any cable: the measured signals are sent to a computer through Bluetooth, and the electric power is provided by battery. The experimental test is conducted with a police dog.日本機械学会ロボティクス・メカトロニクス講演会 2016 in Yokohama 開催日:2016年6月8日平成26年度関西大学若手研究者育成経費 : 研究課題「優れた感覚機能を持つ動物の知覚情報を利用した超拡張現実の実現にむけて

    A Histone-Like Protein of Mycobacteria Possesses Ferritin Superfamily Protein-Like Activity and Protects against DNA Damage by Fenton Reaction

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    Iron is an essential metal for living organisms but its level must be strictly controlled in cells, because ferrous ion induces toxicity by generating highly active reactive oxygen, hydroxyl radicals, through the Fenton reaction. In addition, ferric ion shows low solubility under physiological conditions. To overcome these obstacles living organisms possess Ferritin superfamily proteins that are distributed in all three domains of life: bacteria, archaea, and eukaryotes. These proteins minimize hydroxyl radical formation by ferroxidase activity that converts Fe2+ into Fe3+ and sequesters iron by storing it as a mineral inside a protein cage. In this study, we discovered that mycobacterial DNA-binding protein 1 (MDP1), a histone-like protein, has similar activity to ferritin superfamily proteins. MDP1 prevented the Fenton reaction and protects DNA by the ferroxidase activity. The Km values of the ferroxidase activity by MDP1 of Mycobacterium bovis bacillus Calmette-Guérin (BCG-3007c), Mycobacterium tuberculosis (Rv2986c), and Mycobacterium leprae (ML1683; ML-LBP) were 0.292, 0.252, and 0.129 mM, respectively. Furthermore, one MDP1 molecule directly captured 81.4±19.1 iron atoms, suggesting the role of this protein in iron storage. This study describes for the first time a ferroxidase-iron storage protein outside of the ferritin superfamily proteins and the protective role of this bacterial protein from DNA damage
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