Coa2 is an assembly factor for yeast cytochrome c oxidase biogenesis that facilitates the maturation of Cox1.
The assembly of cytochrome c oxidase (CcO) in yeast mitochondria is dependent on a new assembly factor designated Coa2. Coa2 was identified from its ability to suppress the respiratory deficiency of coa1Delta and shy1Delta cells. Coa1 and Shy1 function at an early step in maturation of the Cox1 subunit of CcO. Coa2 functions downstream of the Mss51-Coa1 step in Cox1 maturation and likely concurrent with the Shy1-related heme a(3) insertion into Cox1. Coa2 interacts with Shy1. Cells lacking Coa2 show a rapid degradation of newly synthesized Cox1. Rapid Cox1 proteolysis also occurs in shy1Delta cells, suggesting that in the absence of Coa2 or Shy1, Cox1 forms an unstable conformer. Overexpression of Cox10 or Cox5a and Cox6 or attenuation of the proteolytic activity of the m-AAA protease partially restores respiration in coa2Delta cells. The matrix-localized Coa2 protein may aid in stabilizing an early Cox1 intermediate containing the nuclear subunits Cox5a and Cox6.
University of Utah Health Sciences Center, Department of Medicine, Salt Lake City, UT 84132, USA.
Fabien
F
Pierrel
Oleh
O
Khalimonchuk
Paul A
PA
Cobine
Megan
M
Bestwick
Dennis R
DR
Winge
D003576:Electron Transport Complex IV / Q000096:biosynthesis* / Q000378:metabolism; D017353:Gene Deletion; D005816:Genetic Complementation Test; D008565:Membrane Proteins / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism; D024101:Mitochondrial Proteins / Q000378:metabolism; D014176:Protein Biosynthesis; D011499:Protein Processing, Post-Translational; D021122:Protein Subunits / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000201:enzymology* / Q000254:growth & development; D029701:Saccharomyces cerevisiae Proteins / Q000096:biosynthesis / Q000378:metabolism*; D012995:Solubility; D013489:Suppression, Genetic; D013816:Thermodynamics
C530854:Coa2 protein, S cerevisiae; D008565:Membrane Proteins; D024101:Mitochondrial Proteins; D021122:Protein Subunits; D029701:Saccharomyces cerevisiae Proteins; C526453:Cox1 protein, S cerevisiae; D003576:Electron Transport Complex IV