Two subunits of the F0F1-ATPase are phosphorylated in the inner mitochondrial membrane

Inside out submitochondrial particles from potato tuber mitochondria were incubated with [gamma-P-32]ATP, More than 16 phosphorylated polypeptides were detected by autoradiography on an SDS-gel, Two phosphoproteins, migrating at 22 and 28 kDa, were excised from the SDS-gel, electroeluted, and purified further by anion chromatography, The phosphoproteins were N-terminally sequenced, Over the regions sequenced, the 22 and 28 kDa phosphoproteins had 100% sequence identity with potato proteins identified as the delta'-subunit of the F-1-ATPase and the b-subunit of the F-o-ATPase, respectively, We suggest that phosphorylation of these proteins may control the interaction between F-1 and F-o and regulate energy coupling in oxidative phosphorylation. (C) 1998 Academic Press.