LAUSR

Gene Regulation When we think of histone proteins, we generally think of H2A, H2B, H3, and H4 because they are the histones that package DNA within our cells. However, other histone variants perform important regulatory and structural roles. Ranjan et al. used single-particle tracking of fluorescently tagged proteins to examine histone variants in yeast cells in vivo and discovered that RNA polymerase II (Pol II) itself evicts H2A.Z from chromatin. In addition, the kinase Kin28/Cdk7, which phosphorylates serine-5 of heptapeptide repeats in the carboxy-terminal domain of the Pol II subunit Rpb1, is required for this eviction. These findings indicate a general mechanism coupling eukaryotic transcription to erasure of the H2A.Z epigenetic signal. eLife 9 , e55667 (2020).