2,575 research outputs found
The Role of Deubiquitinases in DNA Double-Strand Break Repair
DNA double-strand break (DSB) is a type of the most critical DNA lesions, and if not repaired promptly, it can result in cell death or a wide variety of genetic alterations including genome instability, large- or small-scale deletions, chromosome loss, loss of heterozygosity, and translocations. DSBs are repaired by double-strand break repair (DSBR), including nonhomologous end-joining (NHEJ) and homologous recombination (HR) pathway, and defects in these pathways cause genome instability and promote tumorigenesis. Accumulating evidence has demonstrated that the superfamily of deubiquitinases (DUBs) can regulate the action and stability of DNA repair enzymes involving in DSBR via modifying ubiquitination levels, a reversible posttranslational modification pathway. In this review, we will discuss ubiquitination/deubiquitination modification involving in DSBR genes, the role of DUBs in DSBR and corresponding mechanisms, and the potential effects of this modification on human diseases
Effective photon mass in nuclear matter and finite nuclei
Electromagnetic field in nuclear matter and nuclei are studied. In the
nuclear matter, because the expectation value of the electric charge density
operator is not zero, different in vacuum, the U(1) local gauge symmetry of
electric charge is spontaneously broken, and consequently, the photon gains an
effective mass through the Higgs mechanism. An alternative way to study the
effective mass of photon is to calculate the self-energy of photon
perturbatively. It shows that the effective mass of photon is about
in the symmetric nuclear matter at the saturation density and about at the surface of . It seems that
the two-body decay of a massive photon causes the sharp lines of
electron-positron pairs in the low energy heavy ion collision experiments of
.Comment: 10 pages, 2 figures, 1 table, REVTEX4, submitted to Int. J. Mod.
Phys.
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