RESUMO
Silenced heterochromatin influences all nuclear processes including chromosome structure, nuclear organization, transcription, replication, and repair. Proteins that mediate silencing affect all of these nuclear processes. Similarly proteins involved in replication, repair, and chromosome structure play a role in the formation and maintenance of silenced heterochromatin. In this chapter we describe a handful of simple tools and methods that can be used to study the atypical role of proteins in gene silencing.
Assuntos
Proteínas de Ciclo Celular/genética , Inativação Gênica , Biologia Molecular/métodos , Proteínas Nucleares/genética , Proteínas Cromossômicas não Histona , Cromossomos/genética , Reparo do DNA/genética , Replicação do DNA/genética , Proteínas de Ligação a DNA/genética , Heterocromatina/genética , Proteínas de Saccharomyces cerevisiae/genéticaRESUMO
Heterochromatin formation and nuclear organization are important in gene regulation and genome fidelity. Proteins involved in gene silencing localize to sites of damage and some DNA repair proteins localize to heterochromatin, but the biological importance of these correlations remains unclear. In this study, we examined the role of double-strand-break repair proteins in gene silencing and nuclear organization. We find that the ATM kinase Tel1 and the proteins Mre11 and Esc2 can silence a reporter gene dependent on the Sir, as well as on other repair proteins. Furthermore, these proteins aid in the localization of silenced domains to specific compartments in the nucleus. We identify two distinct mechanisms for repair protein-mediated silencing-via direct and indirect interactions with Sir proteins, as well as by tethering loci to the nuclear periphery. This study reveals previously unknown interactions between repair proteins and silencing proteins and suggests insights into the mechanism underlying genome integrity.