Insights into how chromatin remodeling factors find their target in the nucleus

摘要

Enzymes that use energy gained by ATP-hydrolysis to alter nucleo-somes, the building blocks of chromatin, are involved in all processes occurring on DNA (1, 2). These ATP-dependent chromatin remodeling factors regulate access to DNA either by moving nucleosomes away from a tran- scription factor binding site or into such a site, occluding further access (1, 2). All known ATP-dependent nucleosome remodeling factors contain a protein with a highly conserved SWI/SNF-type ATPase core domain. This ATPase is usually imbedded in a complex with other subunits that regulate its function. Despite the importance of these enzymes, we know little of how they operate in the living cell. In a paper published in PNAS, Rippe and coworkers (3) present a study on the mobility of ATP-dependent chromatin remodeling factors in living cells and propose a mechanism by which these factors rapidly identify target sites in the nucleus.