Elimination of radiation-induced {gamma}-H2AX foci in mammalian nucleus can occur by histone exchange
- Institute of Cytology RAS, 194064 St. Petersburg (Russian Federation)
- Department of Biochemistry and Molecular Medicine, University of California Medical School, Davis, CA 95616 (United States)
- Department of Microbiology, University of California, Davis, CA 95616 (United States)
Double-strand breaks in mammalian DNA lead to rapid phosphorylation of C-terminal serines in histone H2AX ({gamma}-H2AX) and formation of large nuclear {gamma}-H2AX foci. After DNA repair these foci disappear, but molecular mechanism of elimination of {gamma}-H2AX foci remains unclear. H2AX protein can be phosphorylated and dephosphorylated in vitro in the absence of chromatin. Here, we compared global exchange of GFP-H2AX with kinetics of formation and elimination of radiation-induced {gamma}-H2AX foci. Maximal number of {gamma}-H2AX foci is observed one hour after irradiation, when {approx}20% of GFP-H2AX is exchanged suggesting that formation of the foci mostly occurs by in situ H2AX phosphorylation. However, slow elimination of {gamma}-H2AX foci is weakly affected by an inhibitor of protein phosphatases calyculin A which is known as an agent suppressing dephosphorylation of {gamma}-H2AX. This indicates that elimination of {gamma}-H2AX foci may be independent of dephosphorylation of H2AX which can occur after its removal from the foci by exchange.
- OSTI ID:
- 20991421
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 358, Issue 2; Other Information: DOI: 10.1016/j.bbrc.2007.04.188; PII: S0006-291X(07)00930-8; Copyright (c) 2007 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Persistence of gamma-H2AX and 53BP1 foci in proliferating and nonproliferating human mammary epithelial cells after exposure to gamma-rays or iron ions
Histone H2AX participates the DNA damage-induced ATM activation through interaction with NBS1