CHIP is a tetratricopeptide repeat (TPR) domain protein that functions as an E3-ubiquitin ligase. As well as linking the molecular chaperones to the ubiquitin proteasome system, CHIP also has a docking-dependent mode where it ubiquitinates native substrates, thereby regulating their steady state levels and/or function. Here we explore the effect of Hsp70 on the docking-dependent E3-ligase activity of CHIP. The TPR-domain is revealed as a binding site for allosteric modulators involved in determining CHIP's dynamic conformation and activity. Biochemical, biophysical and modeling evidence demonstrate that Hsp70-binding to the TPR, or Hsp70-mimetic mutations, regulate CHIP-mediated ubiquitination of p53 and IRF-1 through effects on U-box activity and substrate binding. HDX-MS was used to establish that conformational-inhibition-signals extended from the TPR-domain to the U-box. This underscores inter-domain allosteric regulation of CHIP by the core molecular chaperones. Defining the chaperone-associated TPR-domain of CHIP as a manager of inter-domain communication highlights the potential for scaffolding modules to regulate, as well as assemble, complexes that are fundamental to protein homeostatic control.
- MeSH
- alosterická regulace MeSH
- exprese genu MeSH
- interferonový regulační faktor 1 genetika metabolismus MeSH
- kinetika MeSH
- lidé MeSH
- lymfocyty cytologie metabolismus MeSH
- mapování interakce mezi proteiny MeSH
- molekulární modely MeSH
- nádorové buněčné linie MeSH
- nádorový supresorový protein p53 genetika metabolismus MeSH
- proteasomový endopeptidasový komplex metabolismus MeSH
- proteiny tepelného šoku HSP70 chemie genetika metabolismus MeSH
- sekundární struktura proteinů MeSH
- terciární struktura proteinů MeSH
- ubikvitinace MeSH
- ubikvitinligasy chemie genetika metabolismus MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH