1,653 research outputs found
Spatial and temporal cellular responses to single-strand breaks in human cells
DNA single-strand breaks (SSB) are one of the most frequent DNA lesions produced by reactive oxygen species and during DNA metabolism, but the analysis of cellular responses to SSB remains difficult due to the lack of an experimental method to produce SSB alone in cells. By using human cells expressing a foreign UV damage endonuclease (UVDE) and irradiating the cells with UV through tiny pores in membrane filters, we created SSB in restricted areas in the nucleus by the immediate action of UVDE on UV-induced DNA lesions. Cellular responses to the SSB were characterized by using antibodies and fluorescence microscopy. Upon UV irradiation, poly(ADP-ribose) synthesis occurred immediately in the irradiated area. Simultaneously, but dependent on poly(ADP-ribosyl)ation, XRCC1 was translocated from throughout the nucleus, including nucleoli, to the SSB. The BRCT1 domain of XRCC1 protein was indispensable for its poly(ADP-ribose)-dependent recruitment to the SSB. Proliferating cell nuclear antigen and the p150 subunit of chromatin assembly factor 1 also accumulated at the SSB in a detergent-resistant form, which was significantly reduced by inhibition of poly(ADP-ribose) synthesis. Our results show the importance of poly(ADP-ribosyl)ation in sequential cellular responses to SSB
Wilsonian Effective Action and Entanglement Entropy
This is a continuation of our previous works on entanglement entropy (EE) in
interacting field theories. In arXiv:2103.05303, we have proposed the notion of
gauge theory on Feynman diagrams to calculate EE in quantum
field theories and shown that EE consists of two particular contributions from
propagators and vertices. As shown in the next paper arXiv:2105.02598, the
purely non-Gaussian contributions from interaction vertices can be interpreted
as renormalized correlation functions of composite operators. In this paper, we
will first provide a unified matrix form of EE containing both contributions
from propagators and (classical) vertices, and then extract further
non-Gaussian contributions based on the framework of the Wilsonian
renormalization group. It is conjectured that the EE in the infrared is given
by a sum of all the vertex contributions in the Wilsonian effective action.Comment: 29 pages, 10 figures; typos corrected, published version in Symmetry
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