scholarly journals Coa2 Is an Assembly Factor for Yeast Cytochrome c Oxidase Biogenesis That Facilitates the Maturation of Cox1

2008 ◽  
Vol 28 (16) ◽  
pp. 4927-4939 ◽  
Author(s):  
Fabien Pierrel ◽  
Oleh Khalimonchuk ◽  
Paul A. Cobine ◽  
Megan Bestwick ◽  
Dennis R. Winge
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Proteolytic Activity ◽  
Yeast Mitochondria ◽  
Early Step ◽  
Rapid Degradation ◽  
Respiratory Deficiency ◽  
The Matrix ◽  
Assembly Factor

ABSTRACT 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 coa1Δ and shy1Δ 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 shy1Δ 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 coa2Δ cells. The matrix-localized Coa2 protein may aid in stabilizing an early Cox1 intermediate containing the nuclear subunits Cox5a and Cox6.

scholarly journals Cytochrome c oxidase assembly factor Surf1: Candidate for heme a insertion into subunit I

2012 ◽  
Vol 1817 ◽  
pp. S70
Author(s):  
S. Schimo ◽  
A. Hannappel ◽  
F.A. Bundschuh ◽  
C. Glaubnitz ◽  
K.M. Pos ◽  
...  
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Assembly Factor

scholarly journals THE LOCALIZATION OF CYTOCHROME c OXIDASE ACTIVITY DURING MITOCHONDRIAL SPECIALIZATION IN SPERMIOGENESIS OF PROSOBRANCH SNAILS

1970 ◽  
Vol 18 (3) ◽  
pp. 201-210 ◽  
Author(s):  
WINSTON A. ANDERSON
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Oxidase Activity ◽  
Matrix Material ◽  
Enzyme Reaction ◽  
Cytochemical Study ◽  
Membrane Breakdown ◽  
The Matrix ◽  
Enzyme Molecules ◽  
Matrix Enzyme

This cytochemical study of differentiating prosobranch spermatids demonstrates changes in the localization of intramitochondrial cytochrome c oxidase activity during the course of mitochondrial fusion and internal reorganization. Using the osmiophilic compound 3,3'-diaminobenzidine, activity for cytochrome c oxidase is localized in or on the internal mitochondrial membranes and within the intracristal compartment of metamorphosing mitochondria. However, some enzyme activity consistently appears in the matrix. Enzyme reaction product in the matrix disappears as the internal membranes become organized, and in mature spermatozoa activity for cytochrome c oxidase appears only on cristae and in the intracristal space. It is hypothesized that positive matrix material could either represent enzyme molecules not yet incorporated into membranes or disaggregated products of membrane breakdown associated with remodeling of the cristae.

scholarly journals What Role Does COA6 Play in Cytochrome C Oxidase Biogenesis: A Metallochaperone or Thiol Oxidoreductase, or Both?

2020 ◽  
Vol 21 (19) ◽  
pp. 6983
Author(s):  
Shadi Maghool ◽  
Michael T. Ryan ◽  
Megan J. Maher
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Molecular Mechanisms ◽  
Intermembrane Space ◽  
Copper Binding ◽  
Transport Chain ◽  
Assembly Factor ◽  
Controversial Area ◽  
Thiol Oxidoreductase ◽  
Assembly Activity

Complex IV (cytochrome c oxidase; COX) is the terminal complex of the mitochondrial electron transport chain. Copper is essential for COX assembly, activity, and stability, and is incorporated into the dinuclear CuA and mononuclear CuB sites. Multiple assembly factors play roles in the biogenesis of these sites within COX and the failure of this intricate process, such as through mutations to these factors, disrupts COX assembly and activity. Various studies over the last ten years have revealed that the assembly factor COA6, a small intermembrane space-located protein with a twin CX9C motif, plays a role in the biogenesis of the CuA site. However, how COA6 and its copper binding properties contribute to the assembly of this site has been a controversial area of research. In this review, we summarize our current understanding of the molecular mechanisms by which COA6 participates in COX biogenesis.

scholarly journals CCDC90A (MCUR1) Is a Cytochrome c Oxidase Assembly Factor and Not a Regulator of the Mitochondrial Calcium Uniporter

2015 ◽  
Vol 21 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Vincent Paupe ◽  
Julien Prudent ◽  
Emmanuel P. Dassa ◽  
Olga Zurita Rendon ◽  
Eric A. Shoubridge
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Mitochondrial Calcium ◽  
Mitochondrial Calcium Uniporter ◽  
Calcium Uniporter ◽  
Assembly Factor

scholarly journals Inverse regulation of the yeast COX5 genes by oxygen and heme.

1989 ◽  
Vol 9 (5) ◽  
pp. 1958-1964 ◽  
Author(s):  
M R Hodge ◽  
G Kim ◽  
K Singh ◽  
M G Cumsky
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Environmental Conditions ◽  
Physiological Response ◽  
Biosynthetic Pathway ◽  
Yeast Cells ◽  
Yeast Mitochondria ◽  
Aerobic Growth ◽  
Yeast Strains ◽  
Yeast Genes

The COX5a and COX5b genes encode divergent forms of yeast cytochrome c oxidase subunit V. Although the polypeptide products of the two genes are functionally interchangeable, it is the Va subunit that is normally found in preparations of yeast mitochondria and cytochrome c oxidase. We show here that the predominance of subunit Va stems in part from the differential response of the two genes to the presence of molecular oxygen. Our results indicate that during aerobic growth, COX5a levels were high, while COX5b levels were low. Anaerobically, the pattern was reversed; COX5a levels dropped sevenfold, while those of COX5b were elevated sevenfold. Oxygen appeared to act at the level of transcription through heme, since the addition of heme restored an aerobic pattern of transcription to anaerobically grown cells and the effect of anaerobiosis on COX5 transcription was reproduced in strains containing a mutation in the heme-biosynthetic pathway (hem1). In conjunction with the oxygen-heme response, we determined that the product of the ROX1 gene, a trans-acting regulator of several yeast genes controlled by oxygen, is also involved in COX5 expression. These results, as well as our observation that COX5b expression varied significantly in certain yeast strains, indicate that the COX5 genes undergo a complex pattern of regulation. This regulation, especially the increase in COX5b levels anaerobically, may reflect an attempt to modulate the activity of a key respiratory enzyme in response to varying environmental conditions. The results presented here, as well as those from other laboratories, suggest that the induction or derepression of certain metabolic enzymes during anaerobiosis may be a common and important physiological response in yeast cells.

scholarly journals Intramitochondrial sorting of the precursor to yeast cytochrome c oxidase subunit Va.

1993 ◽  
Vol 121 (5) ◽  
pp. 1021-1029 ◽  
Author(s):  
B R Miller ◽  
M G Cumsky
Keyword(s):  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Mitochondrial Protein ◽  
Inner Membrane ◽  
Oxidase Subunit ◽  
Mitochondrial Inner Membrane ◽  
The Matrix ◽  
Inner Membrane Protein ◽  
Membrane Spanning ◽  
Mitochondrial Heat Shock Protein

We have continued our studies on the import pathway of the precursor to yeast cytochrome c oxidase subunit Va (pVa), a mitochondrial inner membrane protein. Previous work on this precursor demonstrated that import of pVa is unusually efficient, and that inner membrane localization is directed by a membrane-spanning domain in the COOH-terminal third of the protein. Here we report the results of studies aimed at analyzing the intramitochondrial sorting of pVa, as well as the role played by ancillary factors in import and localization of the precursor. We found that pVa was efficiently imported and correctly sorted in mitochondria prepared from yeast strains defective in the function of either mitochondrial heat shock protein (hsp)60 or hsp70. Under identical conditions the import and sorting of another mitochondrial protein, the precursor to the beta subunit of the F1 ATPase, was completely defective. Consistent with previous results demonstrating that the subunit Va precursor is loosely folded, we found that pVa could be efficiently imported into mitochondria after translation in wheat germ extracts. This results suggests that normal levels of extramitochondrial hsp70 are also not required for import of the protein. The results of this study enhance our understanding of the mechanism by which pVa is routed to the mitochondrial inner membrane. They suggest that while the NH2 terminus of pVa is exposed to the matrix and processed by the matrix metalloprotease, the protein remains anchored to the inner membrane before being assembled into a functional holoenzyme complex.

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