NuRD-ZNF827 recruitment to telomeres creates a molecular scaffold for homologous recombination

Abstract

Alternative lengthening of telomeres (ALT) is a homologous recombination (HR)-dependent mechanism for de novo synthesis of telomeric DNA in mammalian cells. Nuclear receptors are bound to the telomeres of cells that use ALT. Here we demonstrate that nuclear receptors recruit ZNF827, a zinc-finger protein of unknown function, which recruits the nucleosome remodeling and histone deacetylation (NuRD) complex via binding to an N-terminal RRK motif within ZNF827. This results in decreased shelterin binding, hypoacetylation of telomeric chromatin, enhanced telomere-telomere interactions and recruitment of HR proteins, and it is critically important for cell viability and proliferation. We propose that NuRD-ZNF827 recruitment to human telomeres causes remodeling of telomeric chromatin and creates an environment that promotes telomere-telomere recombination and integrates and controls multiple mechanistic elements of ALT activity.