Physical and Functional Interactions of Monoubiquitylated Transactivators with the Proteasome

摘要: Destabilization of activator-DNA complexes by the proteasomal ATPases can inhibit transcription limiting activator interaction with DNA. Modification monoubiquitylation protects from this destabilization activity. In study, we probe mechanism protective effect monoubiquitylation. Using novel label transfer and chemical cross-linking techniques, show that ubiquitin contacts ATPase complex directly, apparently via Rpn1 Rpt1. This results in dissociation activation domain-ATPase an allosteric process. A model is proposed which serves to limit lifetime activator-ATPase thus ability unfold dissociate protein-DNA complex.