Arg tyrosine kinase is involved in homologous recombinational DNA repair

金沢大学がん研究所c-Abl plays important roles in cellular response to DNA damage. However, possible roles for Arg (Abl-related gene) in DNA damage response are unknown. Here, we show that ionizing radiation (IR)-induced Rad51 focus formation is reduced in Arg-deficient cells generated from a chicken B cell line by targeted disruption. This is consistent with the findings that Arg-deficient cells display hypersensitivity to IR, elevated frequencies of IR-induced chromosomal aberrations, and reduced targeted integration frequencies. All of these abnormalities in DNA damage repair are also observed in ATM-deficient cells but not in c-Abl-deficient cells. Finally, we show that Arg interacts with and phosphorylates Rad51 in 293T cells. These results suggest that Arg plays a role in homologous recombinational (HR) DNA repair by phosphorylating Rad51

DC Flashover Dynamic Model of Post Insulator under Non-Uniform Pollution between Windward and Leeward Sides

Experience shows that under unidirectional wind or certain terrain, the surface of post insulators is non-uniformly polluted between windward and leeward sides, which affects the flashover characteristics. In this paper, a formulation of residual pollution layer resistance was proposed under this non-uniformity and a typical post insulator was taken as an example to analyze and calculate its residual resistance. The theoretical resistance was verified by numerical simulations using COMSOL Multiphysics. The proposed resistance formulation was then implemented in a DC flashover dynamic model to determine the flashover voltage (Ucal), which was validated by artificial flashover tests. Then the factors affecting DC flashover voltage were analyzed. Research results indicate that: the residual resistance formulation agrees well with simulation results, especially when the arc length exceeds 70% of the leakage distance. The good concordance between theoretical and experimental flashover voltages with most relative error within ±10%, validates the flashover model and its residual resistance formulation. Ucal gets impaired under this non-uniformity. The degree of reduction is related to salt deposit density ratio (m) of windward to leeward side and leeward side area proportion (k)