| description |
In vertebrate cells, centromeres are specified epigenetically through the deposition of the centromere-specific histone CENP-A. Following CENP-A deposition, additional proteins are assembled on centromeric chromatin. Although deposition of CENP-A is critical for centromere specification, it remains unknown whether additional epigenetic features of centromeric chromatin are required for kinetochore assembly. Here, we examined centromere-specific histone modifications at chicken centromeres, which lack highly repetitive sequences using ChIP-seq analysis. We found that H4K20 mono-methylation (H4K20me1) is enriched at centromeres. Immunofluorescence analysis revealed that H4K20me1 is present at all centromeres in human and chicken cells. Based on immunoprecipitation, H4K20me1 occurs primarily on the histone H4 that is assembled as part of the CENP-A nucleosome following deposition of CENP-A into centromeric chromatin. Targeting the H4K20me1-specific demethylase PHF8 to centromeres reduces the level of H4K20me1 at centromeres and results in kinetochore assembly defects. We conclude that H4K20me1 of the CENP-A nucleosome contributes to functional kinetochore assembly. |