Histones H1 are necessary for the condensation of nucleosome chains into higher-order structures. The histones H1.0 are found in cells that are in terminal stages of differentiation or that have low rates of cell division. The RNA edited version has been localized to nuclear speckles. During mitosis, it appears in the vicinity of condensed chromosomes. Both the unedited and the RNA edited versions are induced by butyrate (at protein level). Only RNA edited version is induced by DTT, vinblastine or TNF (at protein level). Phosphorylated on Ser-17 in RNA edited version. ADP-ribosylated on Ser-104 in response to DNA damage. Partially edited. In approximately 3.6% of the mRNA molecules, a new initiator methionine is created by a single uridine insertion in the 5'-UTR, causing an N-terminal extension of 99 amino acids. The existence of the RNA edited version is supported by direct protein sequencing by MS/MS of the following peptides specific to that version: 12-21; 22-33; 37-47; 48-67; 68-83; 84-94 and 97-113. The RNA edited version is called ET-H1.0. Belongs to the histone H1/H5 family. Histone H1 entry