Ultrasensitive Nucleosome Binding Regulation Mediated by Intrinsically Disordered Regions

Proteins expressed in human cells contain about 50% intrinsically disordered regions (IDRs). An unexpectedly large content of IDRs in human proteins prompted exploring how IDRs exert elaborate functions that are not associated with the folded parts of proteins. This review reports the ultrasensitive change in the nucleosome binding of FACT, a nucleosome remodeler, according to the degree of phosphorylation: in which FACT binding ability to nucleosomal DNA changes in a sigmoidal manner along with the number of phosphorylation to the IDR in its DNA binding domain. This finding adds a new function exclusively achieved by IDRs.