A distinct H2A.X isoform is enriched in Xenopus laevis eggs and early embryos and is phosphorylated in the absence of a checkpoint.

ABSTRACT: Histone H2A.X is an H2A variant present in multicellular organisms that is specifically phosphorylated on the serine in the C-terminal consensus sequence, canonically "SQEY," in response to DNA damage. We have recently shown the significance of phosphorylation of the penultimate tyrosine for maintenance and processing of the DNA damage response in mammalian cells. Here, we report the identification of distinct H2A.X variants in the eggs and early embryos of the frog Xenopus laevis that contain a C-terminal SQEF, among other changes; we have denoted these proteins as "H2A.X-F." H2A.X-F is present only in late-staged oocytes, eggs, and premidblastula transition embryos and is not present in somatic cells. Similar unannotated isoforms were identified in other rapidly developing aquatic specie

SUBMITTER: Shechter D 

PROVIDER: S-EPMC2630098 | biostudies-literature | 2009 Jan

REPOSITORIES: biostudies-literature