Year-end Sale % OFF 
Abstract
The F(0)F(1)-ATPase complex of yeast mitochondria contains three mitochondrial and at least 17 nuclear gene products. The coordinate assembly of mitochondrial and cytosolic translation products relies on chaperones and specific factors that stabilize the pools of some unassembled subunits. Atp10p was identified as a mitochondrial inner membrane component necessary for the biogenesis of the hydrophobic F(0) sector of the ATPase. Here we show that, following its synthesis on mitochondrial ribosomes, subunit 6 of the ATPase (Atp6p) can be cross-linked to Atp10p. This interaction is required for the integration of Atp6p into a partially assembled subcomplex of the ATPase. Pulse labeling and chase of mitochondrial translation products in vivo indicate that Atp6p is less stable and more rapidly degraded in an atp10 null mutant than in wild type. Based on these observations, we propose Atp10p to be an Atp6p-specific chaperone that facilitates the incorporation of Atp6p into an intermediate subcomplex of ATPase subunits.
Highlights
Is assembled are based on the analysis of mutants and on what is known about the subunit topology of the complex (1, 6 –9)
This indicated that one of the radiolabeled translation products is in the proximity of Atp10p during or directly following its synthesis in the mitochondria
Atp6p has a mass of ϳ28 kDa, but in the SDS-PAGE system used in this study it migrates as a protein of 22 kDa
Summary
Is assembled are based on the analysis of mutants and on what is known about the subunit topology of the complex (1, 6 –9). The F1 sector assembles independently of the F0 subunits and attaches to the Atp9p ring [10, 11] This complex was reported to be further modified by the addition of Atp8p first [6], followed by Atp4p [8] and perhaps other components of the stator arm. The addition of Atp6p at a late stage of assembly may prevent the exchange of protons across the membrane through the partially assembled F0 sector This scheme is still very fragmentary and is lacking a host of intermolecular interactions of other F0 subunits needed to stabilize the final complex [1, 2, 13]. Based on the results reported here and those of earlier studies, Atp10p is proposed to function as a chaperone that interacts physically with newly synthesized Atp6p and maintains it in an assembly-competent state
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
