Heterochromatin protein 1β (HP1β) dynamics in different nuclear regions. The kinetic properties of HP1β proteins are provided for HP1β accumulated in foci of heterochromatin, nuclear regions outside of foci (likely euchromatin), and HP1β accumulated in nucleoli. This analysis was performed in (a) control MEFs, (b) TSA-treated MEFs, and (c) actinomycin D-treated MEFs. Comparison of HP1β in control (black dots), TSA-treated cells (triangles), and actinomycin D-stimulated (squares) cells. Proteins were analysed (d) in euchromatin or away from foci; e.g. in interchromatin space; (e) nucleoli, and (f) in foci of heterochromatin.