DNA is wrapped into nucleosomes that form chromatin and are rearranged by protein complexes. The INO80 chromatin remodeler enzyme moves nucleosomes along DNA and modifies its protein composition, which is important for many processes including gene regulation and cell differentiation. To better understand how INO80 modifies the protein composition of nucleosomes, researchers led by Blaine Bartholomew, Ph.D., discovered that Arp5 – a protein subunit of INO80 – dynamically rotates, thereby switching the region of Arp5 contacting the nucleosome.
If one of these two contacts is broken, INO80 cannot modify the composition of the nucleosome, which is a crucial activity of INO80 and highlights the potential of targeting Arp5 therapeutically for several biological processes that could be useful in treatment of cancer and other diseases.