TY - JOUR
T1 - Mitochondrial methionyl N-formylation affects steady-state levels of oxidative phosphorylation complexes and their organization into supercomplexes
AU - Arguello, Tania
AU - Köhrer, Caroline
AU - RajBhandary, Uttam L.
AU - Moraes, Carlos T.
N1 - Funding Information:
Supported by a minority supplement to National Institutes of Health Grant 5R01EY010804.
Publisher Copyright:
© 2018 Arguello et al. Published under exclusive license by The American Society for Biochemistry and Molecular Biology, Inc.
PY - 2018/9/28
Y1 - 2018/9/28
N2 - N-Formylation of the Met-tRNAMet by the nuclearly encoded mitochondrial methionyl-tRNA formyltransferase (MTFMT) has been found to be a key determinant of protein synthesis initiation in mitochondria. In humans, mutations in the MTFMTgene result in Leigh syndrome, a progressive and severe neurometabolic disorder. However, the absolute requirement of formylation of Met-tRNAMet for protein synthesis in mammalian mitochondria is still debated. Here, we generated a Mtfmt-KO mouse fibroblast cell line and demonstrated that N-formylation of the first methionine via fMet-tRNAMet by MTFMTis not an absolute requirement for initiation of protein synthesis. However, it differentially affected the efficiency of synthesis of mtDNA-coded polypeptides. Lack of methionine N-formylation did not compromise the stability of these individual subunits but had a marked effect on the assembly and stability of the OXPHOS complexes I and IV and on their supercomplexes. In summary, N-formylation is not essential for mitochondrial protein synthesis but is critical for efficient synthesis of several mitochondrially encoded peptides and for OXPHOS complex stability and assembly into supercomplexes.
AB - N-Formylation of the Met-tRNAMet by the nuclearly encoded mitochondrial methionyl-tRNA formyltransferase (MTFMT) has been found to be a key determinant of protein synthesis initiation in mitochondria. In humans, mutations in the MTFMTgene result in Leigh syndrome, a progressive and severe neurometabolic disorder. However, the absolute requirement of formylation of Met-tRNAMet for protein synthesis in mammalian mitochondria is still debated. Here, we generated a Mtfmt-KO mouse fibroblast cell line and demonstrated that N-formylation of the first methionine via fMet-tRNAMet by MTFMTis not an absolute requirement for initiation of protein synthesis. However, it differentially affected the efficiency of synthesis of mtDNA-coded polypeptides. Lack of methionine N-formylation did not compromise the stability of these individual subunits but had a marked effect on the assembly and stability of the OXPHOS complexes I and IV and on their supercomplexes. In summary, N-formylation is not essential for mitochondrial protein synthesis but is critical for efficient synthesis of several mitochondrially encoded peptides and for OXPHOS complex stability and assembly into supercomplexes.
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U2 - 10.1074/jbc.RA118.003838
DO - 10.1074/jbc.RA118.003838
M3 - Article
C2 - 30087118
AN - SCOPUS:85054058536
VL - 293
SP - 15021
EP - 15032
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 39
ER -