PMID- 22985601
OWN - NLM
STAT- MEDLINE
DCOM- 20121211
LR  - 20161126
IS  - 0006-3002 (Print)
IS  - 0006-3002 (Linking)
VI  - 1817
IP  - 12
DP  - 2012 Dec
TI  - The cytosol-synthesized subunit II (Cox2) precursor with the point mutation W56R 
      is correctly processed in yeast mitochondria to rescue cytochrome oxidase.
PG  - 2128-39
LID - S0005-2728(12)01029-8 [pii]
LID - 10.1016/j.bbabio.2012.09.006 [doi]
AB  - Deletion of the yeast mitochondrial gene COX2 encoding subunit 2 (Cox2) of 
      cytochrome c oxidase (CcO) results in loss of respiration (Deltacox2 strain). 
      Supekova et al. (2010) [1] transformed a Deltacox2 strain with a vector expressing 
      Cox2 with a mitochondrial targeting sequence (MTS) and the point mutation W56R 
      (Cox2(W56R)), restoring respiratory growth. Here, the CcO carrying the 
      allotopically-expressed Cox2(W56R) was characterized. Yeast mitochondria from the 
      wild-type (WT) and the Deltacox2+Cox2(W56R) strains were subjected to Blue Native 
      electrophoresis. In-gel activity of CcO and spectroscopic quantitation of 
      cytochromes revealed that only 60% of CcO is present in the complemented strain, 
      and that less CcO is found associated in supercomplexes as compared to WT. CcOs 
      from the WT and the mutant exhibited similar subunit composition, although 
      activity was 20-25% lower in the enzyme containing Cox2(W56R) than in the one 
      with Cox2(WT). Tandem mass spectrometry confirmed that W(56) was substituted by 
      R(56) in Cox2(W56R). In addition, Cox2(W56R) exhibited the same N-terminus than 
      Cox2(WT), indicating that the MTS of Oxa1 and the leader sequence of 15 residues 
      were removed from Cox2(W56R) during maturation. Thus, Cox2(W56R) is identical to 
      Cox2(WT) except for the point mutation W56R. Mitochondrial Cox1 synthesis is 
      strongly reduced in Deltacox2 mutants, but the Cox2(W56R) complemented strain led to 
      full restoration of Cox1 synthesis. We conclude that the cytosol-synthesized 
      Cox2(W56R) follows a rate-limiting process of import, maturation or assembly that 
      yields lower steady-state levels of CcO. Still, the allotopically-expressed 
      Cox2(W56R) restores CcO activity and allows mitochondrial Cox1 synthesis to 
      advance at WT levels.
CI  - Copyright (c) 2012 Elsevier B.V. All rights reserved.
FAU - Cruz-Torres, Valentin
AU  - Cruz-Torres V
AD  - Instituto de Fisiologia Celular, Universidad Nacional Autonoma de Mexico, Mexico 
      D.F., Mexico.
FAU - Vazquez-Acevedo, Miriam
AU  - Vazquez-Acevedo M
FAU - Garcia-Villegas, Rodolfo
AU  - Garcia-Villegas R
FAU - Perez-Martinez, Xochitl
AU  - Perez-Martinez X
FAU - Mendoza-Hernandez, Guillermo
AU  - Mendoza-Hernandez G
FAU - Gonzalez-Halphen, Diego
AU  - Gonzalez-Halphen D
LA  - eng
PT  - Comparative Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20120915
PL  - Netherlands
TA  - Biochim Biophys Acta
JT  - Biochimica et biophysica acta
JID - 0217513
RN  - 0 (Mitochondrial Proteins)
RN  - 0 (Saccharomyces cerevisiae Proteins)
RN  - EC 1.9.3.- (cytochrome C oxidase subunit II)
RN  - EC 1.9.3.1 (Cox1 protein, S cerevisiae)
RN  - EC 1.9.3.1 (Electron Transport Complex IV)
RN  - S88TT14065 (Oxygen)
SB  - IM
MH  - Amino Acid Sequence
MH  - Cell Respiration/physiology
MH  - Cytoplasm/*enzymology
MH  - Electron Transport Complex IV/chemistry/genetics/*metabolism
MH  - Immunoassay
MH  - Mitochondria/genetics/metabolism
MH  - Mitochondrial Proteins/chemistry/metabolism
MH  - Molecular Sequence Data
MH  - Native Polyacrylamide Gel Electrophoresis
MH  - Oxygen/*metabolism
MH  - Point Mutation/*genetics
MH  - Protein Conformation
MH  - Saccharomyces cerevisiae/*enzymology/genetics
MH  - Saccharomyces cerevisiae Proteins/metabolism
MH  - Tandem Mass Spectrometry
EDAT- 2012/09/19 06:00
MHDA- 2012/12/12 06:00
CRDT- 2012/09/19 06:00
PHST- 2012/05/24 00:00 [received]
PHST- 2012/09/01 00:00 [revised]
PHST- 2012/09/07 00:00 [accepted]
PHST- 2012/09/19 06:00 [entrez]
PHST- 2012/09/19 06:00 [pubmed]
PHST- 2012/12/12 06:00 [medline]
AID - S0005-2728(12)01029-8 [pii]
AID - 10.1016/j.bbabio.2012.09.006 [doi]
PST - ppublish
SO  - Biochim Biophys Acta. 2012 Dec;1817(12):2128-39. doi: 
      10.1016/j.bbabio.2012.09.006. Epub 2012 Sep 15.