Translation initiation of leaderless and polycistronic transcripts in mammalian mitochondria.
Journal
Nucleic acids research
ISSN: 1362-4962
Titre abrégé: Nucleic Acids Res
Pays: England
ID NLM: 0411011
Informations de publication
Date de publication:
25 01 2023
25 01 2023
Historique:
accepted:
09
12
2022
revised:
11
11
2022
received:
04
05
2022
pubmed:
12
1
2023
medline:
31
1
2023
entrez:
11
1
2023
Statut:
ppublish
Résumé
The synthesis of mitochondrial OXPHOS complexes is central to cellular metabolism, yet many molecular details of mitochondrial translation remain elusive. It has been commonly held view that translation initiation in human mitochondria proceeded in a manner similar to bacterial systems, with the mitoribosomal small subunit bound to the initiation factors, mtIF2 and mtIF3, along with initiator tRNA and an mRNA. However, unlike in bacteria, most human mitochondrial mRNAs lack 5' leader sequences that can mediate small subunit binding, raising the question of how leaderless mRNAs are recognized by mitoribosomes. By using novel in vitro mitochondrial translation initiation assays, alongside biochemical and genetic characterization of cellular knockouts of mitochondrial translation factors, we describe unique features of translation initiation in human mitochondria. We show that in vitro, leaderless mRNA transcripts can be loaded directly onto assembled 55S mitoribosomes, but not onto the mitoribosomal small subunit (28S), in a manner that requires initiator fMet-tRNAMet binding. In addition, we demonstrate that in human cells and in vitro, mtIF3 activity is not required for translation of leaderless mitochondrial transcripts but is essential for translation of ATP6 in the case of the bicistronic ATP8/ATP6 transcript. Furthermore, we show that mtIF2 is indispensable for mitochondrial protein synthesis. Our results demonstrate an important evolutionary divergence of the mitochondrial translation system and further our fundamental understanding of a process central to eukaryotic metabolism.
Identifiants
pubmed: 36629253
pii: 6984590
doi: 10.1093/nar/gkac1233
pmc: PMC9881170
doi:
Substances chimiques
Mitochondrial Proteins
0
Peptide Initiation Factors
0
RNA, Messenger
0
Types de publication
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
891-907Subventions
Organisme : Wellcome Trust
ID : 106207
Pays : United Kingdom
Organisme : European Research Council
ID : 646891
Pays : International
Organisme : NIGMS NIH HHS
ID : R01 GM127374
Pays : United States
Informations de copyright
© The Author(s) 2023. Published by Oxford University Press on behalf of Nucleic Acids Research.
Références
Nat Commun. 2019 Sep 5;10(1):4006
pubmed: 31488843
Nucleic Acids Res. 2015 Apr 20;43(7):e47
pubmed: 25605792
Nucleic Acids Res. 2021 Jan 11;49(1):371-382
pubmed: 33300043
FEBS J. 2021 Jan;288(2):437-451
pubmed: 32329962
Biochemistry. 2009 Apr 21;48(15):3269-78
pubmed: 19239245
Nucleic Acids Res. 2020 Sep 25;48(17):9762-9786
pubmed: 32182356
Nat Commun. 2017 Nov 16;8(1):1532
pubmed: 29146908
J Bacteriol. 2017 May 9;199(11):
pubmed: 28320882
Sci Adv. 2019 Dec 20;5(12):eaay2118
pubmed: 31903419
Mol Biol Evol. 2019 Feb 1;36(2):207-219
pubmed: 30517740
Nucleic Acids Res. 2019 Sep 26;47(17):9386-9399
pubmed: 31396629
Mol Microbiol. 2002 Jan;43(1):239-46
pubmed: 11849551
Mol Cell. 2008 Feb 1;29(2):180-90
pubmed: 18243113
J Biol Chem. 2010 Sep 3;285(36):28379-86
pubmed: 20610392
Genome Biol. 2009;10(3):R25
pubmed: 19261174
Science. 2014 Nov 7;346(6210):718-722
pubmed: 25278503
Nat Commun. 2020 Jun 10;11(1):2932
pubmed: 32522994
J Bacteriol. 2002 Dec;184(23):6730-3
pubmed: 12426363
Nature. 2022 Jun;606(7914):603-608
pubmed: 35676484
Mol Cell. 2005 May 13;18(4):403-12
pubmed: 15893724
Elife. 2017 Jul 26;6:
pubmed: 28745585
Nat Biotechnol. 2008 Dec;26(12):1367-72
pubmed: 19029910
Semin Cancer Biol. 2017 Dec;47:67-81
pubmed: 28445780
J Proteome Res. 2011 Apr 1;10(4):1794-805
pubmed: 21254760
Cell Mol Life Sci. 2015 Nov;72(22):4341-67
pubmed: 26259514
Commun Biol. 2019 Dec 6;2:459
pubmed: 31840104
Science. 2015 Apr 3;348(6230):95-98
pubmed: 25838379
Nature. 2014 Nov 13;515(7526):283-6
pubmed: 25271403
Nucleic Acids Res. 2008 Feb;36(2):589-97
pubmed: 18056078
Cell Rep. 2021 Apr 27;35(4):109024
pubmed: 33910005
Annu Rev Genet. 2011;45:299-329
pubmed: 21910628
J Biol Chem. 2004 Mar 5;279(10):8539-46
pubmed: 14670970
Nucleic Acids Res. 2004 Jun 23;32(11):3354-63
pubmed: 15215335
Cell Rep. 2017 Sep 26;20(13):3113-3122
pubmed: 28954228
Proc Natl Acad Sci U S A. 2016 Mar 1;113(9):E1180-9
pubmed: 26888283
Nucleic Acids Res. 2016 Jan 4;44(D1):D1251-7
pubmed: 26450961
Nature. 2018 Aug;560(7717):263-267
pubmed: 30089917
Nat Struct Mol Biol. 2006 Apr;13(4):354-9
pubmed: 16532005
Proc Natl Acad Sci U S A. 2011 Mar 8;108(10):3918-23
pubmed: 21368145
Nucleic Acids Res. 2005 Dec 09;33(22):7011-8
pubmed: 16340009
Sci Rep. 2020 Apr 28;10(1):7110
pubmed: 32346061
Mol Cell Proteomics. 2014 Sep;13(9):2513-26
pubmed: 24942700
Cell. 2016 Sep 22;167(1):133-144.e13
pubmed: 27662086
Proc Natl Acad Sci U S A. 2022 Jan 18;119(3):
pubmed: 35042777
Nucleic Acids Res. 2004 Oct 11;32(18):5464-70
pubmed: 15477394
Science. 2015 Apr 17;348(6232):303-8
pubmed: 25837512
Int J Mol Sci. 2021 Apr 07;22(8):
pubmed: 33917098
Cell. 2013 Sep 12;154(6):1380-9
pubmed: 23992846
Proc Natl Acad Sci U S A. 2013 Sep 24;110(39):15656-61
pubmed: 24029017