HP1, a protein architect that has fallen from grace across evolution

Sanâa Bensaha, Dominika Lewandowska, Fernando Muzzopappa, Michela Anfossi, Christophe Normand and Fabian Erdel (MCD-CBI) and their collaborators studied a protein called HP1, which is involved in DNA organisation. Present in both fission yeast and mammals, this protein can form ‘condensates’ (a kind of droplets), which allow certain regions of DNA to be grouped together to form dense areas of DNA called ‘heterochromatin’. However, this ability has diminished across evolution, eventually disappearing in mice, giving way to other strategies for regulating gene expression.