Nucleosome Binding Properties and Co-Remodeling Activities of Native and in Vivo Acetylated HMGB-1 and HMGB-2 Proteins

The participation of HMGB-1 and -2 proteins in chromatin remodeling is investigated. Here, the ability of these proteins and their posttranslationally acetylated forms to affect SWI/SNF and RSC-dependent nucleosome mobilization was studied. Both proteins assisted nucleosome sliding induced by the two remodelers. Following acetylation, these proteins acquire the ability to bind to core particles, a property that has not yet been documented with parental proteins. We further report that compared to the nonmodified proteins, acetylated HMGB-1 and -2 exhibited both stronger binding to linker DNA-containing nucleosomes and a higher co-remodeling activity. Acetylation of HMGB-1 and -2 proteins enhanced binding of SWI/SNF to the nucleosome but did not affect its ATPase activity.