High impact information on AFG3

• The mitochondrial members of the highly conserved AAA family, Yta10p and Yta12p, constitute a membrane-embedded complex of about 850 kDa [1].
• Afg3p and Rca1p are adenosine triphosphate (ATP)-dependent metalloproteases in yeast mitochondria [2].
• Deletion of YTA10 or YTA12 impairs degradation of non-assembled inner membrane proteins and assembly of respiratory chain complexes [3].
• Mutational inactivation of the proteolytic function of the matrix-localized Yta10p (Afg3p) AAA-protease partially stabilizes Cox2p in an mss2 mutant but does not restore assembly of cytochrome oxidase [4].
• Here we show that both Mrs2 and Yta10 transiently accumulate as sorting intermediates in the matrix before they integrate into the inner membrane [5].

Biological context of AFG3

• Three metalloproteases belonging to the AAA superfamily (Yme1p, Afg3p and Rca1p) are involved in protein turnover and respiratory chain complex assembly in the yeast inner mitochondrial membrane [6].
• Cells harbouring proteolytically inactive forms of both Yta10p and Yta12p are respiratory deficient and exhibit a pleiotropic phenotype similar to Deltayta10 and Deltayta12 cells [3].
• Yta10p, as deduced from the nucleotide sequence, is 761 amino acids in length (predicted molecular mass 84.5 kDa) [7].
• We report here that Yta10p is a yeast mitochondrial protein and that import is dependent on a membrane potential and accompanied by processing to a protein of approximately 73 kDa [7].
• Yta10p-dependent degradation requires divalent metal ions and the hydrolysis of ATP [8].

Anatomical context of AFG3

• Several features of Yta10p are compatible with its localization in mitochondria [7].

Other interactions of AFG3

• Neither Afg3p nor Yme1p is responsible for the degradation of Cox subunits [9].
• Three genes for mitochondrial proteins suppress null-mutations in both Afg3 and Rca1 when over-expressed [10].

References