Involvement of Yme1 Regulatory Proteins in F1F0-ATPase Assembly

Previous studies in the Thorsness lab provided genetic evidence for participation of the Yme1 protein and the Hsp90 proteins, Hsc82 and Hsp82, in the assembly of the molecular motor F1 Fo-ATPase in the inner membrane of yeast mitochondria. Loss of Yme1 allows growth of strains lacking Hsc82 or Hsp82. Yme1 appears to be regulated by three proteins, Mgr1, Mgr2 and Mgr3. Under some conditions loss of one of these three proteins can have growth effects similar to the loss of Yme1. This project has determined the effect of removing each of the regulatory proteins on growth of strains lacking Hsc82 or Hsp82, to see if they might also be involved in assembly of F1 Fo-ATPase. Although an effect on growth similar to the loss of Yme1 has not so far been observed, germination of Hsc82-or Hsp82-depleted spores is significantly impaired by removal of either Yme1 or Mgr1, suggesting that Yme1 and Mgr1 proteins are involved in the assembly/organization of F1 Fo-ATPase in the mitochondria of spores.