Reevaluation of the role of the Pam18:Pam16 interaction in translocation of proteins by the mitochondrial Hsp70-based import motor.

ABSTRACT: The heat-shock protein 70 (Hsp70)-based import motor, associated with the translocon on the matrix side of the mitochondrial inner membrane, drives translocation of proteins via cycles of binding and release. Stimulation of Hsp70's ATPase activity by the translocon-associated J-protein Pam18 is critical for this process. Pam18 forms a heterodimer with the structurally related protein Pam16, via their J-type domains. This interaction has been proposed to perform a critical regulatory function, inhibiting the ATPase stimulatory activity of Pam18. Using biochemical and genetic assays, we tested this hypothesis by assessing the in vivo function of Pam18 variants having altered abilities to stimulate Hsp70's ATPase activity. The observed pattern of genetic interactions was opposite from that pr

SUBMITTER: Pais JE 

PROVIDER: S-EPMC3237618 | biostudies-literature | 2011 Dec

REPOSITORIES: biostudies-literature