A Heterotypic Assembly Mechanism Regulates CHIP E3 Ligase Activity

ABSTRACT: CHIP (C-terminus of Hsc70-interacting protein) and its worm ortholog CHN-1 are E3 ubiquitin ligases that link the chaperone system with the ubiquitin-proteasome system (UPS). CHN-1 can cooperate with UFD-2, another E3, to accelerate ubiquitin chain formation; however, the basis for the high processivity of this E3 set has remained obscure. Here we studied the molecular mechanism and function of the CHN-1-UFD-2 complex in Caenorhabditis elegans. Our data show that UFD-2 binding promotes the cooperation between CHN-1 and ubiquitin-conjugating E2 enzymes by stabilizing the CHN-1 U-box dimer. However, HSP70/HSP-1 chaperone outcompetes UFD-2 for CHN-1 binding, thereby promoting a shift to the autoinhibited CHN-1 state by acting on a conserved residue in its U-box domain. The interaction with U

SUBMITTER: Mr. Aniruddha Das 

PROVIDER: S-SCDT-EMBOJ-2021-109566 | biostudies-other |

REPOSITORIES: biostudies-other