Catalysis of proline isomerization and molecular chaperone activity in a tug-of-war.

ABSTRACT: Catalysis of cis/trans isomerization of prolines is important for the activity and misfolding of intrinsically disordered proteins. Catalysis is achieved by peptidylprolyl isomerases, a superfamily of molecular chaperones. Here, we provide atomic insight into a tug-of-war between cis/trans isomerization and molecular chaperone activity. Catalysis of proline isomerization by cyclophilin A lowers the energy barrier for α-synuclein misfolding, while isomerase-binding to a separate, disease-associated protein region opposes aggregation. We further show that cis/trans isomerization outpowers the holding activity of cyclophilin A. Removal of the proline isomerization barrier through posttranslational truncation of α-synuclein reverses the action of the proline isomerase and turns it into a potent molecular chaperone that inhibits protein misfolding. The data reveal a conserved mechanism of dual functionality in cis/trans isomerases and define its molecular determinants acting on intrinsically disordered proteins.

SUBMITTER: Favretto F 

PROVIDER: S-EPMC7695863 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature