Apoptosome Formation through Disruption of the K192-D616 Salt Bridge in the Apaf-1 Closed Form.

ABSTRACT: The molecular mechanism of apoptosome activation through conformational changes of Apaf-1 auto-inhibited form remains largely enigmatic. The crystal structure of Apaf-1 suggests that some ionic bonds, including the bond between K192 and D616, are critical for the preservation of the inactive "closed" form of Apaf-1. Here, a split luciferase complementation assay was used to monitor the effect of disrupting this ionic bond on apoptosome activation and caspase-3 activity in cells. The K192E mutation, predicted to disrupt the ionic interaction with D616, increased apoptosome formation and caspase activity, suggesting that this mutation favors the "open"/active form of Apaf-1. However, mutation of D616 to alanine or lysine had different effects. While both mutants favored apoptosome formation

SUBMITTER: Sahebazzamani F 

PROVIDER: S-EPMC8427654 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature