Maintaining the end: Roles of telomere proteins in end-protection, telomere replication and length regulation

► Telomere proteins participate in telomere protection, replication and length regulation. ► Mammalian telomeres are protected by the shelterin complex. ► Telomeres may switch between closed, protected and open, replication-competent states. ► Telomere replication is a multi-step process that involves telomerase, CST and shelterin. ► Defects in telomere replication and loss of telomere protection can impact human health.