1
|
Brischigliaro M, Sierra-Magro A, Ahn A, Barrientos A. Mitochondrial ribosome biogenesis and redox sensing. FEBS Open Bio 2024; 14:1640-1655. [PMID: 38849194 DOI: 10.1002/2211-5463.13844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 05/06/2024] [Accepted: 05/29/2024] [Indexed: 06/09/2024] Open
Abstract
Mitoribosome biogenesis is a complex process involving RNA elements encoded in the mitochondrial genome and mitoribosomal proteins typically encoded in the nuclear genome. This process is orchestrated by extra-ribosomal proteins, nucleus-encoded assembly factors, which play roles across all assembly stages to coordinate ribosomal RNA processing and maturation with the sequential association of ribosomal proteins. Both biochemical studies and recent cryo-EM structures of mammalian mitoribosomes have provided insights into their assembly process. In this article, we will briefly outline the current understanding of mammalian mitoribosome biogenesis pathways and the factors involved. Special attention is devoted to the recent identification of iron-sulfur clusters as structural components of the mitoribosome and a small subunit assembly factor, the existence of redox-sensitive cysteines in mitoribosome proteins and assembly factors, and the role they may play as redox sensor units to regulate mitochondrial translation under stress.
Collapse
Affiliation(s)
| | - Ana Sierra-Magro
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA
| | - Ahram Ahn
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, FL, USA
| | - Antoni Barrientos
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, FL, USA
- Bruce W. Carter Department of Veterans Affairs VA Medical Center, Miami, FL, USA
| |
Collapse
|
2
|
Singh V, Itoh Y, Del'Olio S, Hassan A, Naschberger A, Flygaard RK, Nobe Y, Izumikawa K, Aibara S, Andréll J, Whitford PC, Barrientos A, Taoka M, Amunts A. Mitoribosome structure with cofactors and modifications reveals mechanism of ligand binding and interactions with L1 stalk. Nat Commun 2024; 15:4272. [PMID: 38769321 PMCID: PMC11106087 DOI: 10.1038/s41467-024-48163-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Accepted: 04/19/2024] [Indexed: 05/22/2024] Open
Abstract
The mitoribosome translates mitochondrial mRNAs and regulates energy conversion that is a signature of aerobic life forms. We present a 2.2 Å resolution structure of human mitoribosome together with validated mitoribosomal RNA (rRNA) modifications, including aminoacylated CP-tRNAVal. The structure shows how mitoribosomal proteins stabilise binding of mRNA and tRNA helping to align it in the decoding center, whereas the GDP-bound mS29 stabilizes intersubunit communication. Comparison between different states, with respect to tRNA position, allowed us to characterize a non-canonical L1 stalk, and molecular dynamics simulations revealed how it facilitates tRNA transitions in a way that does not require interactions with rRNA. We also report functionally important polyamines that are depleted when cells are subjected to an antibiotic treatment. The structural, biochemical, and computational data illuminate the principal functional components of the translation mechanism in mitochondria and provide a description of the structure and function of the human mitoribosome.
Collapse
Affiliation(s)
- Vivek Singh
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165, Solna, Sweden
| | - Yuzuru Itoh
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165, Solna, Sweden
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 113-0033, Tokyo, Japan
| | - Samuel Del'Olio
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Asem Hassan
- Department of Physics, Northeastern University, Boston, MA, 02115, USA
- Center for Theoretical Biological Physics, Northeastern University, Boston, MA, 02115, USA
| | - Andreas Naschberger
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165, Solna, Sweden
- King Abdullah University of Science and Technology, Thuwal, 23955, Saudi Arabia
| | - Rasmus Kock Flygaard
- Department of Molecular Biology and Genetics, Danish Research Institute of Translational Neuroscience - DANDRITE, Nordic EMBL Partnership for Molecular Medicine, Aarhus University, 8000, Aarhus C, Denmark
| | - Yuko Nobe
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minami-osawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Keiichi Izumikawa
- Department of Molecular and Cellular Biochemistry, Meiji Pharmaceutical University, 2-522-1, Noshio, Kiyose-shi, Tokyo, 204-8588, Japan
| | - Shintaro Aibara
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165, Solna, Sweden
| | - Juni Andréll
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, 17177, Stockholm, Sweden
| | - Paul C Whitford
- Department of Physics, Northeastern University, Boston, MA, 02115, USA
- Center for Theoretical Biological Physics, Northeastern University, Boston, MA, 02115, USA
| | - Antoni Barrientos
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
- Department of Neurology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Masato Taoka
- Department of Chemistry, Graduate School of Science, Tokyo Metropolitan University, Minami-osawa 1-1, Hachioji-shi, Tokyo, 192-0397, Japan
| | - Alexey Amunts
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, 17165, Solna, Sweden.
- Westlake University, Hangzhou, China.
| |
Collapse
|
3
|
Seffouh A, Nikolay R, Ortega J. Critical steps in the assembly process of the bacterial 50S ribosomal subunit. Nucleic Acids Res 2024; 52:4111-4123. [PMID: 38554105 PMCID: PMC11077053 DOI: 10.1093/nar/gkae199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2023] [Revised: 03/02/2024] [Accepted: 03/07/2024] [Indexed: 04/01/2024] Open
Abstract
During assembly, ribosomal particles in bacteria fold according to energy landscapes comprised of multiple parallel pathways. Cryo-electron microscopy studies have identified a critical maturation step that occurs during the late assembly stages of the 50S subunit in Bacillus subtilis. This step acts as a point of convergency for all the parallel assembly pathways of the subunit, where an assembly intermediate accumulates in a 'locked' state, causing maturation to pause. Assembly factors then act on this critical step to 'unlock' the last maturation steps involving the functional sites. Without these factors, the 50S subunit fails to complete its assembly, causing cells to die due to a lack of functional ribosomes to synthesize proteins. In this review, we analyze these findings in B. subtilis and examine other cryo-EM studies that have visualized assembly intermediates in different bacterial species, to determine if convergency points in the ribosome assembly process are a common theme among bacteria. There are still gaps in our knowledge, as these methodologies have not yet been applied to diverse species. However, identifying and characterizing these convergency points can reveal how different bacterial species implement unique mechanisms to regulate critical steps in the ribosome assembly process.
Collapse
Affiliation(s)
- Amal Seffouh
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
- Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| | - Rainer Nikolay
- Department of Genome Regulation, Max Planck Institute for Molecular Genetics, 14195 Berlin, Germany
| | - Joaquin Ortega
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 0C7, Canada
- Centre for Structural Biology, McGill University, Montreal, Quebec H3G 0B1, Canada
| |
Collapse
|
4
|
Zhong H, Barrientos A. The zinc finger motif in the mitochondrial large ribosomal subunit protein bL36m is essential for optimal yeast mitoribosome assembly and function. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119707. [PMID: 38493895 PMCID: PMC11009049 DOI: 10.1016/j.bbamcr.2024.119707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 03/08/2024] [Accepted: 03/11/2024] [Indexed: 03/19/2024]
Abstract
Ribosomes across species contain subsets of zinc finger proteins that play structural roles by binding to rRNA. While the majority of these zinc fingers belong to the C2-C2 type, the large subunit protein L36 in bacteria and mitochondria exhibits an atypical C2-CH motif. To comprehend the contribution of each coordinating residue in S. cerevisiae bL36m to mitoribosome assembly and function, we engineered and characterized strains carrying single and double mutations in the zinc coordinating residues. Our findings reveal that although all four residues markedly influence protein stability, C to A mutations in C66 and/or C69 have a more pronounced effect compared to those at C82 and H88. Importantly, protein stability directly correlates with the assembly and function of the mitoribosome and the growth rate of yeast in respiratory conditions. Mass spectrometry analysis of large subunit particles indicates that strains deleted for bL36m or expressing mutant variants have defective assembly of the L7/L12 stalk base, limiting their functional competence. Furthermore, we employed a synthetic bL36m protein collection, including both wild-type and mutant proteins, to elucidate their ability to bind zinc. Our data indicate that mutations in C82 and, particularly, H88 allow for some zinc binding albeit inefficient or unstable, explaining the residual accumulation and activity in mitochondria of bL36m variants carrying mutations in these residues. In conclusion, stable zinc binding by bL36m is essential for optimal mitoribosome assembly and function. MS data are available via ProteomeXchange with identifierPXD046465.
Collapse
Affiliation(s)
- Hui Zhong
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 1600 NW 10th Ave., Miami, FL 33136, USA.
| | - Antoni Barrientos
- Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, 1600 NW 10th Ave., Miami, FL 33136, USA; Department of Neurology, University of Miami Miller School of Medicine, 1600 NW 10th Ave., Miami, FL 33136, USA; The Miami Veterans Affairs (VA) Medical System, 1201 NW 16th St, Miami, FL 33125, USA.
| |
Collapse
|
5
|
Key J, Gispert S, Koepf G, Steinhoff-Wagner J, Reichlmeir M, Auburger G. Translation Fidelity and Respiration Deficits in CLPP-Deficient Tissues: Mechanistic Insights from Mitochondrial Complexome Profiling. Int J Mol Sci 2023; 24:17503. [PMID: 38139332 PMCID: PMC10743472 DOI: 10.3390/ijms242417503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/07/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023] Open
Abstract
The mitochondrial matrix peptidase CLPP is crucial during cell stress. Its loss causes Perrault syndrome type 3 (PRLTS3) with infertility, neurodegeneration, and a growth deficit. Its target proteins are disaggregated by CLPX, which also regulates heme biosynthesis via unfolding ALAS enzymes, providing access for pyridoxal-5'-phosphate (PLP). Despite efforts in diverse organisms with multiple techniques, CLPXP substrates remain controversial. Here, avoiding recombinant overexpression, we employed complexomics in mitochondria from three mouse tissues to identify endogenous targets. A CLPP absence caused the accumulation and dispersion of CLPX-VWA8 as AAA+ unfoldases, and of PLPBP. Similar changes and CLPX-VWA8 co-migration were evident for mitoribosomal central protuberance clusters, translation factors like GFM1-HARS2, the RNA granule components LRPPRC-SLIRP, and enzymes OAT-ALDH18A1. Mitochondrially translated proteins in testes showed reductions to <30% for MTCO1-3, the mis-assembly of the complex IV supercomplex, and accumulated metal-binding assembly factors COX15-SFXN4. Indeed, heavy metal levels were increased for iron, molybdenum, cobalt, and manganese. RT-qPCR showed compensatory downregulation only for Clpx mRNA; most accumulated proteins appeared transcriptionally upregulated. Immunoblots validated VWA8, MRPL38, MRPL18, GFM1, and OAT accumulation. Co-immunoprecipitation confirmed CLPX binding to MRPL38, GFM1, and OAT, so excess CLPX and PLP may affect their activity. Our data mechanistically elucidate the mitochondrial translation fidelity deficits which underlie progressive hearing impairment in PRLTS3.
Collapse
Affiliation(s)
- Jana Key
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
| | - Suzana Gispert
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
| | - Gabriele Koepf
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
| | - Julia Steinhoff-Wagner
- TUM School of Life Sciences, Animal Nutrition and Metabolism, Technical University of Munich, Liesel-Beckmann-Str. 2, 85354 Freising-Weihenstephan, Germany;
| | - Marina Reichlmeir
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
| | - Georg Auburger
- Goethe University Frankfurt, University Hospital, Clinic of Neurology, Exp. Neurology, Heinrich Hoffmann Str. 7, 60590 Frankfurt am Main, Germany; (S.G.); (M.R.); (G.A.)
| |
Collapse
|
6
|
Dhembla C, Kumar A, Arya R, Kundu S, Sundd M. Mitochondrial Acyl Carrier Protein of Leishmania major Displays Features Distinct from the Canonical Type II ACP. Biochemistry 2023; 62:3347-3359. [PMID: 37967383 DOI: 10.1021/acs.biochem.3c00455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2023]
Abstract
Prokaryotes synthesize fatty acids using a type II synthesis pathway (FAS). In this process, the central player, i.e., the acyl carrier protein (ACP), sequesters the growing acyl chain in its internal hydrophobic cavity. As the acyl chain length increases, the cavity expands in size, which is reflected in the NMR chemical shift perturbations and crystal structures of the acyl-ACP intermediates. A few eukaryotic organelles, such as plastids and mitochondria, also harbor type II fatty acid synthesis machinery. Plastid FAS from spinach and Plasmodium falciparum has been characterized at the molecular level, but the mitochondrial pathway remains unexplored. Here, we report NMR studies of the mitochondrial acyl-acyl carrier protein intermediates of Leishmania major (acyl-LmACP). Our studies show that LmACP experiences remarkably small conformational changes upon acylation, with perturbations confined to helices II and III only. CastP determined that the cavity size of apo-LmACP (PDB entry 5ZWT) is less than that of Escherichia coli ACP (PDB 1T8K). Thus, the small chemical shift perturbations observed in the LmACP intermediates, coupled with CastP results, suggest an unusually small cavity when fully expanded. The faster rate of C8-LmACP chain hydrolysis compared to E. coli ACP (EcACP) also supports these convictions. Structure comparison of LmACP with other type II ACP disclosed unique differences in the helix I and loop I conformations, as well as several residues present there. Numerous hydrophobic residues in helix I and loop I (conserved in all mitochondrial ACPs) are substituted with hydrophilic residues in the bacterial/plastid type II ACP. For instance, Phe and leucine at positions 14 and 34 in LmACP are substituted with a hydrophilic residue and Ala in bacterial/plastid type II ACP. Mutation of Leu 34 to Ala (corresponding residue in EcACP) resulted in a complete loss of structure, underscoring its importance in maintaining the ACP fold. Thus, our NMR studies, combined with insights from the crystal structure, highlight several unique features of LmACP, distinct from the prokaryote and plastid type II ACP. Given the high sequence identity, the features might be conserved in all mitochondrial ACPs.
Collapse
Affiliation(s)
- Chetna Dhembla
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Ambrish Kumar
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India
| | - Richa Arya
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Suman Kundu
- Department of Biochemistry, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Monica Sundd
- National Institute of Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India
| |
Collapse
|
7
|
Nguyen TG, Ritter C, Kummer E. Structural insights into the role of GTPBP10 in the RNA maturation of the mitoribosome. Nat Commun 2023; 14:7991. [PMID: 38042949 PMCID: PMC10693566 DOI: 10.1038/s41467-023-43599-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 11/14/2023] [Indexed: 12/04/2023] Open
Abstract
Mitochondria contain their own genetic information and a dedicated translation system to express it. The mitochondrial ribosome is assembled from mitochondrial-encoded RNA and nuclear-encoded ribosomal proteins. Assembly is coordinated in the mitochondrial matrix by biogenesis factors that transiently associate with the maturing particle. Here, we present a structural snapshot of a large mitoribosomal subunit assembly intermediate containing 7 biogenesis factors including the GTPases GTPBP7 and GTPBP10. Our structure illustrates how GTPBP10 aids the folding of the ribosomal RNA during the biogenesis process, how this process is related to bacterial ribosome biogenesis, and why mitochondria require two biogenesis factors in contrast to only one in bacteria.
Collapse
Affiliation(s)
- Thu Giang Nguyen
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Christina Ritter
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark
| | - Eva Kummer
- Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen, Denmark.
| |
Collapse
|
8
|
Zhong H, Janer A, Khalimonchuk O, Antonicka H, Shoubridge E, Barrientos A. BOLA3 and NFU1 link mitoribosome iron-sulfur cluster assembly to multiple mitochondrial dysfunctions syndrome. Nucleic Acids Res 2023; 51:11797-11812. [PMID: 37823603 PMCID: PMC10681725 DOI: 10.1093/nar/gkad842] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Revised: 09/08/2023] [Accepted: 09/20/2023] [Indexed: 10/13/2023] Open
Abstract
The human mitochondrial ribosome contains three [2Fe-2S] clusters whose assembly pathway, role, and implications for mitochondrial and metabolic diseases are unknown. Here, structure-function correlation studies show that the clusters play a structural role during mitoribosome assembly. To uncover the assembly pathway, we have examined the effect of silencing the expression of Fe-S cluster biosynthetic and delivery factors on mitoribosome stability. We find that the mitoribosome receives its [2Fe-2S] clusters from the GLRX5-BOLA3 node. Additionally, the assembly of the small subunit depends on the mitoribosome biogenesis factor METTL17, recently reported containing a [4Fe-4S] cluster, which we propose is inserted via the ISCA1-NFU1 node. Consistently, fibroblasts from subjects suffering from 'multiple mitochondrial dysfunction' syndrome due to mutations in BOLA3 or NFU1 display previously unrecognized attenuation of mitochondrial protein synthesis that contributes to their cellular and pathophysiological phenotypes. Finally, we report that, in addition to their structural role, one of the mitoribosomal [2Fe-2S] clusters and the [4Fe-4S] cluster in mitoribosome assembly factor METTL17 sense changes in the redox environment, thus providing a way to regulate organellar protein synthesis accordingly.
Collapse
Affiliation(s)
- Hui Zhong
- Department of Biochemistry and Molecular Biology. University of Miami Miller School of Medicine, 1600 NW 10Ave. Miami, FL 33136, USA
| | - Alexandre Janer
- The Neuro and Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Oleh Khalimonchuk
- Department of Biochemistry. University of Nebraska-Lincoln; 1901 Vine St. Beadle Center, Lincoln, NE 68588, USA
- Nebraska Redox Biology Center. University of Nebraska-Lincoln; 1901 Vine St. Beadle Center, Lincoln, NE 68588, USA
| | - Hana Antonicka
- The Neuro and Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Eric A Shoubridge
- The Neuro and Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Antoni Barrientos
- Department of Biochemistry and Molecular Biology. University of Miami Miller School of Medicine, 1600 NW 10Ave. Miami, FL 33136, USA
- Department of Neurology. University of Miami Miller School of Medicine; 1600 NW 10 Ave., Miami, FL 33136, USA
| |
Collapse
|
9
|
Singh V, Itoh Y, Del'Olio S, Hassan A, Naschberger A, Flygaard RK, Nobe Y, Izumikawa K, Aibara S, Andréll J, Whitford PC, Barrientos A, Taoka M, Amunts A. Structure of mitoribosome reveals mechanism of mRNA binding, tRNA interactions with L1 stalk, roles of cofactors and rRNA modifications. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.24.542018. [PMID: 37503168 PMCID: PMC10369894 DOI: 10.1101/2023.05.24.542018] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
The mitoribosome translates mitochondrial mRNAs and regulates energy conversion that is a signature of aerobic life forms. We present a 2.2 Å resolution structure of human mitoribosome together with validated mitoribosomal RNA (rRNA) modifications, including aminoacylated CP-tRNA Val . The structure shows how mitoribosomal proteins stabilise binding of mRNA and tRNA helping to align it in the decoding center, whereas the GDP-bound mS29 stabilizes intersubunit communication. Comparison between different states, with respect to tRNA position, allowed to characterize a non-canonical L1 stalk, and molecular dynamics simulations revealed how it facilitates tRNA transition in a way that does not require interactions with rRNA. We also report functionally important polyamines that are depleted when cells are subjected to an antibiotic treatment. The structural, biochemical, and computational data illuminate the principal functional components of the translation mechanism in mitochondria and provide the most complete description so far of the structure and function of the human mitoribosome.
Collapse
|
10
|
Valach M, Benz C, Aguilar LC, Gahura O, Faktorová D, Zíková A, Oeffinger M, Burger G, Gray MW, Lukeš J. Miniature RNAs are embedded in an exceptionally protein-rich mitoribosome via an elaborate assembly pathway. Nucleic Acids Res 2023; 51:6443-6460. [PMID: 37207340 PMCID: PMC10325924 DOI: 10.1093/nar/gkad422] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 04/20/2023] [Accepted: 05/08/2023] [Indexed: 05/21/2023] Open
Abstract
The mitochondrial ribosome (mitoribosome) has diverged drastically from its evolutionary progenitor, the bacterial ribosome. Structural and compositional diversity is particularly striking in the phylum Euglenozoa, with an extraordinary protein gain in the mitoribosome of kinetoplastid protists. Here we report an even more complex mitoribosome in diplonemids, the sister-group of kinetoplastids. Affinity pulldown of mitoribosomal complexes from Diplonema papillatum, the diplonemid type species, demonstrates that they have a mass of > 5 MDa, contain as many as 130 integral proteins, and exhibit a protein-to-RNA ratio of 11:1. This unusual composition reflects unprecedented structural reduction of ribosomal RNAs, increased size of canonical mitoribosomal proteins, and accretion of three dozen lineage-specific components. In addition, we identified >50 candidate assembly factors, around half of which contribute to early mitoribosome maturation steps. Because little is known about early assembly stages even in model organisms, our investigation of the diplonemid mitoribosome illuminates this process. Together, our results provide a foundation for understanding how runaway evolutionary divergence shapes both biogenesis and function of a complex molecular machine.
Collapse
Affiliation(s)
- Matus Valach
- Department of Biochemistry and Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montréal, Quebec, Canada
| | - Corinna Benz
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
| | - Lisbeth C Aguilar
- Center for Genetic and Neurological Diseases, Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada
| | - Ondřej Gahura
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
| | - Drahomíra Faktorová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
- Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Alena Zíková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
- Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Marlene Oeffinger
- Department of Biochemistry and Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montréal, Quebec, Canada
- Center for Genetic and Neurological Diseases, Institut de recherches cliniques de Montréal (IRCM), Montréal, Quebec, Canada
- Division of Experimental Medicine, McGill University, Montréal, Quebec, Canada
| | - Gertraud Burger
- Department of Biochemistry and Robert-Cedergren Centre for Bioinformatics and Genomics, Université de Montréal, Montréal, Quebec, Canada
| | - Michael W Gray
- Department of Biochemistry and Molecular Biology and Institute of Comparative Genomics, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic
- Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| |
Collapse
|
11
|
Khawaja A, Cipullo M, Krüger A, Rorbach J. Insights into mitoribosomal biogenesis from recent structural studies. Trends Biochem Sci 2023; 48:629-641. [PMID: 37169615 DOI: 10.1016/j.tibs.2023.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 05/13/2023]
Abstract
The mitochondrial ribosome (mitoribosome) is a multicomponent machine that has unique structural features. Biogenesis of the human mitoribosome includes correct maturation and folding of the mitochondria-encoded RNA components (12S and 16S mt-rRNAs, and mt-tRNAVal) and their assembly together with 82 nucleus-encoded mitoribosomal proteins. This complex process requires the coordinated action of multiple assembly factors. Recent advances in single-particle cryo-electron microscopy (cryo-EM) have provided detailed insights into the specific functions of several mitoribosome assembly factors and have defined their timing. In this review we summarize mitoribosomal small (mtSSU) and large subunit (mtLSU) biogenesis based on structural findings, and we discuss potential crosstalk between mtSSU and mtLSU assembly pathways as well as coordination between mitoribosome biogenesis and other processes involved in mitochondrial gene expression.
Collapse
Affiliation(s)
- Anas Khawaja
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65 Solna, Sweden; Max Planck Institute Biology of Ageing, Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Miriam Cipullo
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65 Solna, Sweden; Max Planck Institute Biology of Ageing, Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Annika Krüger
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65 Solna, Sweden; Max Planck Institute Biology of Ageing, Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Joanna Rorbach
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Biomedicum, 171 65 Solna, Sweden; Max Planck Institute Biology of Ageing, Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden.
| |
Collapse
|
12
|
Wenger C, Harsman A, Niemann M, Oeljeklaus S, von Känel C, Calderaro S, Warscheid B, Schneider A. The Mba1 homologue of Trypanosoma brucei is involved in the biogenesis of oxidative phosphorylation complexes. Mol Microbiol 2023; 119:537-550. [PMID: 36829306 DOI: 10.1111/mmi.15048] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 02/16/2023] [Accepted: 02/21/2023] [Indexed: 02/26/2023]
Abstract
Consistent with other eukaryotes, the Trypanosoma brucei mitochondrial genome encodes mainly hydrophobic core subunits of the oxidative phosphorylation system. These proteins must be co-translationally inserted into the inner mitochondrial membrane and are synthesized by the highly unique trypanosomal mitoribosomes, which have a much higher protein to RNA ratio than any other ribosome. Here, we show that the trypanosomal orthologue of the mitoribosome receptor Mba1 (TbMba1) is essential for normal growth of procyclic trypanosomes but redundant in the bloodstream form, which lacks an oxidative phosphorylation system. Proteomic analyses of TbMba1-depleted mitochondria from procyclic cells revealed reduced levels of many components of the oxidative phosphorylation system, most of which belong to the cytochrome c oxidase (Cox) complex, three subunits of which are mitochondrially encoded. However, the integrity of the mitoribosome and its interaction with the inner membrane were not affected. Pull-down experiments showed that TbMba1 forms a dynamic interaction network that includes the trypanosomal Mdm38/Letm1 orthologue and a trypanosome-specific factor that stabilizes the CoxI and CoxII mRNAs. In summary, our study suggests that the function of Mba1 in the biogenesis of membrane subunits of OXPHOS complexes is conserved among yeast, mammals and trypanosomes, which belong to two eukaryotic supergroups.
Collapse
Affiliation(s)
- Christoph Wenger
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Anke Harsman
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Moritz Niemann
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Silke Oeljeklaus
- Faculty of Chemistry and Pharmacy, Biochemistry II, Theodor Boveri-Institute, University of Würzburg, Würzburg, Germany
| | - Corinne von Känel
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Salvatore Calderaro
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland
| | - Bettina Warscheid
- Faculty of Chemistry and Pharmacy, Biochemistry II, Theodor Boveri-Institute, University of Würzburg, Würzburg, Germany.,CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - André Schneider
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern, Switzerland.,Institute for Advanced Study (Wissenschaftskolleg) Berlin, Berlin, Germany
| |
Collapse
|
13
|
Rahman MT, Koski MK, Panecka-Hofman J, Schmitz W, Kastaniotis AJ, Wade RC, Wierenga RK, Hiltunen JK, Autio KJ. An engineered variant of MECR reductase reveals indispensability of long-chain acyl-ACPs for mitochondrial respiration. Nat Commun 2023; 14:619. [PMID: 36739436 PMCID: PMC9899272 DOI: 10.1038/s41467-023-36358-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 01/25/2023] [Indexed: 02/06/2023] Open
Abstract
Mitochondrial fatty acid synthesis (mtFAS) is essential for respiratory function. MtFAS generates the octanoic acid precursor for lipoic acid synthesis, but the role of longer fatty acid products has remained unclear. The structurally well-characterized component of mtFAS, human 2E-enoyl-ACP reductase (MECR) rescues respiratory growth and lipoylation defects of a Saccharomyces cerevisiae Δetr1 strain lacking native mtFAS enoyl reductase. To address the role of longer products of mtFAS, we employed in silico molecular simulations to design a MECR variant with a shortened substrate binding cavity. Our in vitro and in vivo analyses indicate that the MECR G165Q variant allows synthesis of octanoyl groups but not long chain fatty acids, confirming the validity of our computational approach to engineer substrate length specificity. Furthermore, our data imply that restoring lipoylation in mtFAS deficient yeast strains is not sufficient to support respiration and that long chain acyl-ACPs generated by mtFAS are required for mitochondrial function.
Collapse
Affiliation(s)
- M Tanvir Rahman
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | | | - Joanna Panecka-Hofman
- Faculty of Physics, University of Warsaw, Warsaw, Poland
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Germany
| | - Werner Schmitz
- Faculty of Biochemistry and Molecular Biology, University of Würzburg, Würzburg, Germany
| | | | - Rebecca C Wade
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Germany
- Zentrum für Molekulare Biologie (ZMBH), DKFZ-ZMBH Alliance and Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Heidelberg, Germany
| | - Rik K Wierenga
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - J Kalervo Hiltunen
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Kaija J Autio
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland.
| |
Collapse
|
14
|
Harper NJ, Burnside C, Klinge S. Principles of mitoribosomal small subunit assembly in eukaryotes. Nature 2023; 614:175-181. [PMID: 36482135 PMCID: PMC9892005 DOI: 10.1038/s41586-022-05621-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 12/02/2022] [Indexed: 12/13/2022]
Abstract
Mitochondrial ribosomes (mitoribosomes) synthesize proteins encoded within the mitochondrial genome that are assembled into oxidative phosphorylation complexes. Thus, mitoribosome biogenesis is essential for ATP production and cellular metabolism1. Here we used cryo-electron microscopy to determine nine structures of native yeast and human mitoribosomal small subunit assembly intermediates, illuminating the mechanistic basis for how GTPases are used to control early steps of decoding centre formation, how initial rRNA folding and processing events are mediated, and how mitoribosomal proteins have active roles during assembly. Furthermore, this series of intermediates from two species with divergent mitoribosomal architecture uncovers both conserved principles and species-specific adaptations that govern the maturation of mitoribosomal small subunits in eukaryotes. By revealing the dynamic interplay between assembly factors, mitoribosomal proteins and rRNA that are required to generate functional subunits, our structural analysis provides a vignette for how molecular complexity and diversity can evolve in large ribonucleoprotein assemblies.
Collapse
Affiliation(s)
- Nathan J Harper
- Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, NY, USA
- Tri-Institutional Training Program in Chemical Biology, The Rockefeller University, New York, NY, USA
| | - Chloe Burnside
- Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, NY, USA
- Tri-Institutional Training Program in Chemical Biology, The Rockefeller University, New York, NY, USA
| | - Sebastian Klinge
- Laboratory of Protein and Nucleic Acid Chemistry, The Rockefeller University, New York, NY, USA.
| |
Collapse
|
15
|
Conor Moran J, Del'Olio S, Choi A, Zhong H, Barrientos A. Mitoribosome Biogenesis. Methods Mol Biol 2023; 2661:23-51. [PMID: 37166630 PMCID: PMC10639111 DOI: 10.1007/978-1-0716-3171-3_3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Mitoribosome biogenesis is a complex and energetically costly process that involves RNA elements encoded in the mitochondrial genome and mitoribosomal proteins most frequently encoded in the nuclear genome. The process is catalyzed by extra-ribosomal proteins, nucleus-encoded assembly factors that act in all stages of the assembly process to coordinate the processing and maturation of ribosomal RNAs with the hierarchical association of ribosomal proteins. Biochemical studies and recent cryo-EM structures of mammalian mitoribosomes have provided hints regarding their assembly. In this general concept chapter, we will briefly describe the current knowledge, mainly regarding the mammalian mitoribosome biogenesis pathway and factors involved, and will emphasize the biological sources and approaches that have been applied to advance the field.
Collapse
Affiliation(s)
- J Conor Moran
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Samuel Del'Olio
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Austin Choi
- Department of Neurology, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Hui Zhong
- Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Antoni Barrientos
- Department of Neurology and Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, FL, USA.
| |
Collapse
|
16
|
Del'Olio S, Barrientos A. Systematic Analysis of Assembly Intermediates in Yeast to Decipher the Mitoribosome Assembly Pathway. Methods Mol Biol 2023; 2661:163-191. [PMID: 37166638 PMCID: PMC10654547 DOI: 10.1007/978-1-0716-3171-3_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Studies of yeast mitoribosome assembly have been historically hampered by the difficulty of generating mitoribosome protein-coding gene deletion strains with a stable mitochondrial genome. The identification of mitochondrial DNA-stabilizing approaches allows for the generation of a complete set of yeast deletion strains covering all mitoribosome proteins and known assembly factors. These strains can be used to analyze the integrity and assembly state of mitoribosomes by determining the sedimentation profile of these structures by sucrose gradient centrifugation of mitochondrial extracts, coupled to mass spectrometry analysis of mitoribosome composition. Subsequent hierarchical cluster analysis of mitoribosome subassemblies accumulated in mutant strains reveals details regarding the order of protein association during the mitoribosome biogenetic process. These strains also allow the expression of truncated protein variants to probe the role of mitochondrion-specific protein extensions, the relevance of protein cofactors, or the importance of RNA-protein interactions in functional sites of the mitoribosome. In this chapter, we will detail the methodology involved in these studies.
Collapse
Affiliation(s)
- Samuel Del'Olio
- Department of Molecular and Cellular Pharmacology, University of Miami, Miller School of Medicine, Miami, FL, USA
| | - Antoni Barrientos
- Department of Neurology and Department of Biochemistry and Molecular Biology, University of Miami, Miller School of Medicine, Miami, FL, USA.
| |
Collapse
|
17
|
Yelland JN, Bravo JPK, Black JJ, Taylor DW, Johnson AW. A single 2'-O-methylation of ribosomal RNA gates assembly of a functional ribosome. Nat Struct Mol Biol 2023; 30:91-98. [PMID: 36536102 PMCID: PMC9851907 DOI: 10.1038/s41594-022-00891-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 11/04/2022] [Indexed: 12/24/2022]
Abstract
RNA modifications are widespread in biology and abundant in ribosomal RNA. However, the importance of these modifications is not well understood. We show that methylation of a single nucleotide, in the catalytic center of the large subunit, gates ribosome assembly. Massively parallel mutational scanning of the essential nuclear GTPase Nog2 identified important interactions with rRNA, particularly with the 2'-O-methylated A-site base Gm2922. We found that methylation of G2922 is needed for assembly and efficient nuclear export of the large subunit. Critically, we identified single amino acid changes in Nog2 that completely bypass dependence on G2922 methylation and used cryoelectron microscopy to directly visualize how methylation flips Gm2922 into the active site channel of Nog2. This work demonstrates that a single RNA modification is a critical checkpoint in ribosome biogenesis, suggesting that such modifications can play an important role in regulation and assembly of macromolecular machines.
Collapse
Affiliation(s)
- James N Yelland
- Interdisciplinary Life Sciences Graduate Program, University of Texas at Austin, Austin, TX, USA
| | - Jack P K Bravo
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
| | - Joshua J Black
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - David W Taylor
- Interdisciplinary Life Sciences Graduate Program, University of Texas at Austin, Austin, TX, USA.
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA.
- Center for Systems and Synthetic Biology, University of Texas at Austin, Austin, TX, USA.
- Livestrong Cancer Institutes, Dell Medical School, Austin, TX, USA.
| | - Arlen W Johnson
- Interdisciplinary Life Sciences Graduate Program, University of Texas at Austin, Austin, TX, USA.
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, USA.
| |
Collapse
|
18
|
Mechanisms and players of mitoribosomal biogenesis revealed in trypanosomatids. Trends Parasitol 2022; 38:1053-1067. [PMID: 36075844 DOI: 10.1016/j.pt.2022.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/29/2022] [Accepted: 08/16/2022] [Indexed: 01/13/2023]
Abstract
Translation in mitochondria is mediated by mitochondrial ribosomes, or mitoribosomes, complex ribonucleoprotein machines with dual genetic origin. Mitoribosomes in trypanosomatid parasites diverged markedly from their bacterial ancestors and other eukaryotic lineages in terms of protein composition, rRNA content, and overall architecture, yet their core functional elements remained conserved. Recent cryo-electron microscopy studies provided atomic models of trypanosomatid large and small mitoribosomal subunits and their precursors, making these parasites the organisms with the best-understood biogenesis of mitoribosomes. The structures revealed molecular mechanisms and players involved in the assembly of mitoribosomes not only in the parasites, but also in eukaryotes in general.
Collapse
|
19
|
Durrieu-Gaillard S, Sissler M, Hashem Y. Purification of Mitochondrial Ribosomal Complexes from Trypanosoma cruzi and Leishmania tarentolae for Cryo-EM Analysis. Bio Protoc 2022; 12:e4425. [PMID: 35865117 PMCID: PMC9183961 DOI: 10.21769/bioprotoc.4425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 04/05/2022] [Accepted: 04/11/2022] [Indexed: 12/29/2022] Open
Abstract
Kinetoplastids are unicellular eukaryotic parasites responsible for human pathologies such as Chagas disease, sleeping sickness or Leishmaniasis, caused by Trypanosoma cruzi, Trypanosoma brucei, and various Leishmania spp., respectively. They harbor a single large mitochondrion that is essential for the survival of the parasite. Interestingly, most of the mitochondrial gene expression machineries and processes present significant differences from their nuclear and cytosolic counterparts. A striking example concerns their mitochondrial ribosomes, in charge of translating the few essential mRNAs encoded by mitochondrial genomes. Here, we present a detailed protocol including the specific procedures to isolate mitochondria from two species of kinetoplastids, T. cruzi and L. tarentolae, by differential centrifugations. Then, we detail the protocol to purify mitochondrial ribosomal complexes from these two species of parasites (including ribosomal maturating complexes) by a sucrose gradient approach. Finally, we describe how to prepare cryo-electron microscopy (cryo-EM) grids from these two sorts of samples. This protocol will be useful for further studies aiming at analyzing mitochondrial translation regulation.
Collapse
Affiliation(s)
| | - Marie Sissler
- Institut Europeen de Chimie et Biologie, U1212 Inserm/UMR5320 CNRS, Universite,
*For correspondence: ;
| | - Yaser Hashem
- Institut Europeen de Chimie et Biologie, U1212 Inserm/UMR5320 CNRS, Universite,
*For correspondence: ;
| |
Collapse
|
20
|
Hammond M, Dorrell RG, Speijer D, Lukeš J. Eukaryotic cellular intricacies shape mitochondrial proteomic complexity. Bioessays 2022; 44:e2100258. [PMID: 35318703 DOI: 10.1002/bies.202100258] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/08/2022] [Accepted: 03/09/2022] [Indexed: 12/17/2022]
Abstract
Mitochondria have been fundamental to the eco-physiological success of eukaryotes since the last eukaryotic common ancestor (LECA). They contribute essential functions to eukaryotic cells, above and beyond classical respiration. Mitochondria interact with, and complement, metabolic pathways occurring in other organelles, notably diversifying the chloroplast metabolism of photosynthetic organisms. Here, we integrate existing literature to investigate how mitochondrial metabolism varies across the landscape of eukaryotic evolution. We illustrate the mitochondrial remodelling and proteomic changes undergone in conjunction with major evolutionary transitions. We explore how the mitochondrial complexity of the LECA has been remodelled in specific groups to support subsequent evolutionary transitions, such as the acquisition of chloroplasts in photosynthetic species and the emergence of multicellularity. We highlight the versatile and crucial roles played by mitochondria during eukaryotic evolution, extending from its huge contribution to the development of the LECA itself to the dynamic evolution of individual eukaryote groups, reflecting both their current ecologies and evolutionary histories.
Collapse
Affiliation(s)
- Michael Hammond
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic.,Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| | - Richard G Dorrell
- Institut de Biologie de l'ENS (IBENS), Département de Biologie, École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Dave Speijer
- Medical Biochemistry, UMC, University of Amsterdam, Amsterdam, The Netherlands
| | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic.,Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic
| |
Collapse
|
21
|
Scaltsoyiannes V, Corre N, Waltz F, Giegé P. Types and Functions of Mitoribosome-Specific Ribosomal Proteins across Eukaryotes. Int J Mol Sci 2022; 23:ijms23073474. [PMID: 35408834 PMCID: PMC8998825 DOI: 10.3390/ijms23073474] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Revised: 03/17/2022] [Accepted: 03/21/2022] [Indexed: 02/04/2023] Open
Abstract
Mitochondria are key organelles that combine features inherited from their bacterial endosymbiotic ancestor with traits that arose during eukaryote evolution. These energy producing organelles have retained a genome and fully functional gene expression machineries including specific ribosomes. Recent advances in cryo-electron microscopy have enabled the characterization of a fast-growing number of the low abundant membrane-bound mitochondrial ribosomes. Surprisingly, mitoribosomes were found to be extremely diverse both in terms of structure and composition. Still, all of them drastically increased their number of ribosomal proteins. Interestingly, among the more than 130 novel ribosomal proteins identified to date in mitochondria, most of them are composed of a-helices. Many of them belong to the nuclear encoded super family of helical repeat proteins. Here we review the diversity of functions and the mode of action held by the novel mitoribosome proteins and discuss why these proteins that share similar helical folds were independently recruited by mitoribosomes during evolution in independent eukaryote clades.
Collapse
Affiliation(s)
- Vassilis Scaltsoyiannes
- CNRS, Institut de Biologie Moléculaire des Plantes, Université de Strasbourg, 67084 Strasbourg, France; (V.S.); (N.C.)
| | - Nicolas Corre
- CNRS, Institut de Biologie Moléculaire des Plantes, Université de Strasbourg, 67084 Strasbourg, France; (V.S.); (N.C.)
| | - Florent Waltz
- CNRS, Institut de Biologie Moléculaire des Plantes, Université de Strasbourg, 67084 Strasbourg, France; (V.S.); (N.C.)
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Munich, Germany
- Correspondence: (F.W.); (P.G.); Tel.: +33-3-6715-5363 (P.G.); Fax: +33-3-8861-4442 (P.G.)
| | - Philippe Giegé
- CNRS, Institut de Biologie Moléculaire des Plantes, Université de Strasbourg, 67084 Strasbourg, France; (V.S.); (N.C.)
- Correspondence: (F.W.); (P.G.); Tel.: +33-3-6715-5363 (P.G.); Fax: +33-3-8861-4442 (P.G.)
| |
Collapse
|
22
|
Santos B, Zeng R, Jorge SF, Ferreira-Junior JR, Barrientos A, Barros MH. Functional analyses of mitoribosome 54S subunit devoid of mitochondria-specific protein sequences. Yeast 2022; 39:208-229. [PMID: 34713496 PMCID: PMC8969203 DOI: 10.1002/yea.3678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 12/17/2022] Open
Abstract
In Saccharomyces cerevisiae, mitoribosomes are composed of a 54S large subunit (mtLSU) and a 37S small subunit (mtSSU). The two subunits altogether contain 73 mitoribosome proteins (MRPs) and two ribosomal RNAs (rRNAs). Although mitoribosomes preserve some similarities with their bacterial counterparts, they have significantly diverged by acquiring new proteins, protein extensions, and new RNA segments, adapting the mitoribosome to the synthesis of highly hydrophobic membrane proteins. In this study, we investigated the functional relevance of mitochondria-specific protein extensions at the C-terminus (C) or N-terminus (N) present in 19 proteins of the mtLSU. The studied mitochondria-specific extensions consist of long tails and loops extending from globular domains that mainly interact with mitochondria-specific proteins and 21S rRNA moieties extensions. The expression of variants devoid of extensions in uL4 (C), uL5 (N), uL13 (N), uL13 (C), uL16 (C), bL17 (N), bL17 (C), bL21 (24), uL22 (N), uL23 (N), uL23 (C), uL24 (C), bL27 (C), bL28 (N), bL28 (C), uL29 (N), uL29 (C), uL30 (C), bL31 (C), and bL32 (C) did not rescue the mitochondrial protein synthesis capacities and respiratory growth of the respective null mutants. On the contrary, the truncated form of the mitoribosome exit tunnel protein uL24 (N) yields a partially functional mitoribosome. Also, the removal of mitochondria-specific sequences from uL1 (N), uL3 (N), uL16 (N), bL9 (N), bL19 (C), uL29 (C), and bL31 (N) did not affect the mitoribosome function and respiratory growth. The collection of mutants described here provides new means to study and evaluate defective assembly modules in the mitoribosome biogenesis process.
Collapse
Affiliation(s)
- Barbara Santos
- Departamento de Microbiologia, Universidade de São Paulo, São Paulo, Brazil
| | - Rui Zeng
- Department of Neurology University of Miami Miller School of Medicine, Miami, USA
| | - Sasa F. Jorge
- Departamento de Microbiologia, Universidade de São Paulo, São Paulo, Brazil
| | | | - Antoni Barrientos
- Department of Neurology University of Miami Miller School of Medicine, Miami, USA
| | - Mario H. Barros
- Departamento de Microbiologia, Universidade de São Paulo, São Paulo, Brazil
| |
Collapse
|
23
|
Lenarčič T, Niemann M, Ramrath DJF, Calderaro S, Flügel T, Saurer M, Leibundgut M, Boehringer D, Prange C, Horn EK, Schneider A, Ban N. Mitoribosomal small subunit maturation involves formation of initiation-like complexes. Proc Natl Acad Sci U S A 2022; 119:e2114710118. [PMID: 35042777 PMCID: PMC8784144 DOI: 10.1073/pnas.2114710118] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 10/29/2021] [Indexed: 01/02/2023] Open
Abstract
Mitochondrial ribosomes (mitoribosomes) play a central role in synthesizing mitochondrial inner membrane proteins responsible for oxidative phosphorylation. Although mitoribosomes from different organisms exhibit considerable structural variations, recent insights into mitoribosome assembly suggest that mitoribosome maturation follows common principles and involves a number of conserved assembly factors. To investigate the steps involved in the assembly of the mitoribosomal small subunit (mt-SSU) we determined the cryoelectron microscopy structures of middle and late assembly intermediates of the Trypanosoma brucei mitochondrial small subunit (mt-SSU) at 3.6- and 3.7-Å resolution, respectively. We identified five additional assembly factors that together with the mitochondrial initiation factor 2 (mt-IF-2) specifically interact with functionally important regions of the rRNA, including the decoding center, thereby preventing premature mRNA or large subunit binding. Structural comparison of assembly intermediates with mature mt-SSU combined with RNAi experiments suggests a noncanonical role of mt-IF-2 and a stepwise assembly process, where modular exchange of ribosomal proteins and assembly factors together with mt-IF-2 ensure proper 9S rRNA folding and protein maturation during the final steps of assembly.
Collapse
Affiliation(s)
- Tea Lenarčič
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Moritz Niemann
- Department of Chemistry, Biochemistry, and Pharmaceutical Sciences, University of Bern, CH-3012 Bern, Switzerland
| | - David J F Ramrath
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Salvatore Calderaro
- Department of Chemistry, Biochemistry, and Pharmaceutical Sciences, University of Bern, CH-3012 Bern, Switzerland
| | - Timo Flügel
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Martin Saurer
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Marc Leibundgut
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Daniel Boehringer
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Céline Prange
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Elke K Horn
- Department of Chemistry, Biochemistry, and Pharmaceutical Sciences, University of Bern, CH-3012 Bern, Switzerland
| | - André Schneider
- Department of Chemistry, Biochemistry, and Pharmaceutical Sciences, University of Bern, CH-3012 Bern, Switzerland
| | - Nenad Ban
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, CH-8093 Zurich, Switzerland;
| |
Collapse
|
24
|
Hierarchical folding of the catalytic core during mitochondrial ribosome biogenesis. Trends Cell Biol 2021; 32:182-185. [PMID: 34635384 DOI: 10.1016/j.tcb.2021.09.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/14/2021] [Accepted: 09/16/2021] [Indexed: 12/22/2022]
Abstract
Final maturation steps during ribosome biogenesis require the assistance of assembly and quality control factors to ensure the folding of rRNA and proteins into a functional translation machinery. Here we integrate several recent structural snapshots of native large ribosomal subunit intermediates into the complex pathway of mitochondrial ribosome assembly.
Collapse
|
25
|
Affiliation(s)
- Marie Sissler
- ARNA - UMR5320 CNRS - U1212 INSERM, Université de Bordeaux, IECB, Pessac, France.
| | - Yaser Hashem
- ARNA - UMR5320 CNRS - U1212 INSERM, Université de Bordeaux, IECB, Pessac, France.
| |
Collapse
|
26
|
Hilander T, Jackson CB, Robciuc M, Bashir T, Zhao H. The roles of assembly factors in mammalian mitoribosome biogenesis. Mitochondrion 2021; 60:70-84. [PMID: 34339868 DOI: 10.1016/j.mito.2021.07.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 02/08/2023]
Abstract
As ancient bacterial endosymbionts of eukaryotic cells, mitochondria have retained their own circular DNA as well as protein translation system including mitochondrial ribosomes (mitoribosomes). In recent years, methodological advancements in cryoelectron microscopy and mass spectrometry have revealed the extent of the evolutionary divergence of mitoribosomes from their bacterial ancestors and their adaptation to the synthesis of 13 mitochondrial DNA encoded oxidative phosphorylation complex subunits. In addition to the structural data, the first assembly pathway maps of mitoribosomes have started to emerge and concomitantly also the assembly factors involved in this process to achieve fully translational competent particles. These transiently associated factors assist in the intricate assembly process of mitoribosomes by enhancing protein incorporation, ribosomal RNA folding and modification, and by blocking premature or non-native protein binding, for example. This review focuses on summarizing the current understanding of the known mammalian mitoribosome assembly factors and discussing their possible roles in the assembly of small or large mitoribosomal subunits.
Collapse
Affiliation(s)
- Taru Hilander
- Faculty of Biological and Environmental Sciences, University of Helsinki, Finland.
| | - Christopher B Jackson
- Department of Biochemistry and Developmental Biology, Faculty of Medicine, University of Helsinki, Finland.
| | - Marius Robciuc
- Faculty of Biological and Environmental Sciences, University of Helsinki, Finland
| | - Tanzeela Bashir
- Faculty of Biological and Environmental Sciences, University of Helsinki, Finland
| | - Hongxia Zhao
- Faculty of Biological and Environmental Sciences, University of Helsinki, Finland; Key Laboratory of Stem Cell and Biopharmaceutical Technology, School of Life Sciences, Guangxi Normal University, Guangxi, China.
| |
Collapse
|
27
|
Cheng J, Berninghausen O, Beckmann R. A distinct assembly pathway of the human 39S late pre-mitoribosome. Nat Commun 2021; 12:4544. [PMID: 34315873 PMCID: PMC8316566 DOI: 10.1038/s41467-021-24818-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 07/01/2021] [Indexed: 02/03/2023] Open
Abstract
Assembly of the mitoribosome is largely enigmatic and involves numerous assembly factors. Little is known about their function and the architectural transitions of the pre-ribosomal intermediates. Here, we solve cryo-EM structures of the human 39S large subunit pre-ribosomes, representing five distinct late states. Besides the MALSU1 complex used as bait for affinity purification, we identify several assembly factors, including the DDX28 helicase, MRM3, GTPBP10 and the NSUN4-mTERF4 complex, all of which keep the 16S rRNA in immature conformations. The late transitions mainly involve rRNA domains IV and V, which form the central protuberance, the intersubunit side and the peptidyltransferase center of the 39S subunit. Unexpectedly, we find deacylated tRNA in the ribosomal E-site, suggesting a role in 39S assembly. Taken together, our study provides an architectural inventory of the distinct late assembly phase of the human 39S mitoribosome.
Collapse
Affiliation(s)
- Jingdong Cheng
- Gene Center and Department for Biochemistry, LMU Munich, München, Germany.
| | - Otto Berninghausen
- Gene Center and Department for Biochemistry, LMU Munich, München, Germany
| | - Roland Beckmann
- Gene Center and Department for Biochemistry, LMU Munich, München, Germany.
| |
Collapse
|
28
|
Cipullo M, Gesé GV, Khawaja A, Hällberg BM, Rorbach J. Structural basis for late maturation steps of the human mitoribosomal large subunit. Nat Commun 2021; 12:3673. [PMID: 34135318 PMCID: PMC8209036 DOI: 10.1038/s41467-021-23617-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 05/07/2021] [Indexed: 01/29/2023] Open
Abstract
Mitochondrial ribosomes (mitoribosomes) synthesize a critical set of proteins essential for oxidative phosphorylation. Therefore, mitoribosomal function is vital to the cellular energy supply. Mitoribosome biogenesis follows distinct molecular pathways that remain poorly understood. Here, we determine the cryo-EM structures of mitoribosomes isolated from human cell lines with either depleted or overexpressed mitoribosome assembly factor GTPBP5, allowing us to capture consecutive steps during mitoribosomal large subunit (mt-LSU) biogenesis. Our structures provide essential insights into the last steps of 16S rRNA folding, methylation and peptidyl transferase centre (PTC) completion, which require the coordinated action of nine assembly factors. We show that mammalian-specific MTERF4 contributes to the folding of 16S rRNA, allowing 16 S rRNA methylation by MRM2, while GTPBP5 and NSUN4 promote fine-tuning rRNA rearrangements leading to PTC formation. Moreover, our data reveal an unexpected involvement of the elongation factor mtEF-Tu in mt-LSU assembly, where mtEF-Tu interacts with GTPBP5, similar to its interaction with tRNA during translational elongation.
Collapse
Affiliation(s)
- Miriam Cipullo
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solna, Sweden
- Max Planck Institute Biology of Ageing-Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - Genís Valentín Gesé
- Department of Cell and Molecular Biology, Karolinska Institutet, Solna, Sweden
| | - Anas Khawaja
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solna, Sweden
- Max Planck Institute Biology of Ageing-Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden
| | - B Martin Hällberg
- Department of Cell and Molecular Biology, Karolinska Institutet, Solna, Sweden.
- Centre for Structural Systems Biology (CSSB) and Karolinska Institutet VR-RÅC, Hamburg, Germany.
| | - Joanna Rorbach
- Department of Medical Biochemistry and Biophysics, Division of Molecular Metabolism, Karolinska Institutet, Solna, Sweden.
- Max Planck Institute Biology of Ageing-Karolinska Institutet Laboratory, Karolinska Institutet, Stockholm, Sweden.
| |
Collapse
|
29
|
Lenarčič T, Jaskolowski M, Leibundgut M, Scaiola A, Schönhut T, Saurer M, Lee RG, Rackham O, Filipovska A, Ban N. Stepwise maturation of the peptidyl transferase region of human mitoribosomes. Nat Commun 2021; 12:3671. [PMID: 34135320 PMCID: PMC8208988 DOI: 10.1038/s41467-021-23811-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 05/07/2021] [Indexed: 02/08/2023] Open
Abstract
Mitochondrial ribosomes are specialized for the synthesis of membrane proteins responsible for oxidative phosphorylation. Mammalian mitoribosomes have diverged considerably from the ancestral bacterial ribosomes and feature dramatically reduced ribosomal RNAs. The structural basis of the mammalian mitochondrial ribosome assembly is currently not well understood. Here we present eight distinct assembly intermediates of the human large mitoribosomal subunit involving seven assembly factors. We discover that the NSUN4-MTERF4 dimer plays a critical role in the process by stabilizing the 16S rRNA in a conformation that exposes the functionally important regions of rRNA for modification by the MRM2 methyltransferase and quality control interactions with the conserved mitochondrial GTPase MTG2 that contacts the sarcin-ricin loop and the immature active site. The successive action of these factors leads to the formation of the peptidyl transferase active site of the mitoribosome and the folding of the surrounding rRNA regions responsible for interactions with tRNAs and the small ribosomal subunit.
Collapse
Affiliation(s)
- Tea Lenarčič
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Mateusz Jaskolowski
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Marc Leibundgut
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Alain Scaiola
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Tanja Schönhut
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Martin Saurer
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland
| | - Richard G Lee
- Harry Perkins Institute of Medical Research, QEII Medical Centre, University of Western Australia, Nedlands, WA, Australia
- ARC Centre of Excellence in Synthetic Biology, QEII Medical Centre, University of Western Australia, Nedlands, WA, Australia
| | - Oliver Rackham
- Harry Perkins Institute of Medical Research, QEII Medical Centre, University of Western Australia, Nedlands, WA, Australia
- ARC Centre of Excellence in Synthetic Biology, QEII Medical Centre, University of Western Australia, Nedlands, WA, Australia
- Curtin Health Innovation Research Institute and Curtin Medical School, Curtin University, Bentley, WA, Australia
- Telethon Kids Institute, Northern Entrance, Perth Children's Hospital, Nedlands, WA, Australia
| | - Aleksandra Filipovska
- Harry Perkins Institute of Medical Research, QEII Medical Centre, University of Western Australia, Nedlands, WA, Australia
- ARC Centre of Excellence in Synthetic Biology, QEII Medical Centre, University of Western Australia, Nedlands, WA, Australia
- Telethon Kids Institute, Northern Entrance, Perth Children's Hospital, Nedlands, WA, Australia
| | - Nenad Ban
- Department of Biology, Institute of Molecular Biology and Biophysics, ETH Zurich, Zurich, Switzerland.
| |
Collapse
|
30
|
Záhonová K, Lax G, Sinha SD, Leonard G, Richards TA, Lukeš J, Wideman JG. Single-cell genomics unveils a canonical origin of the diverse mitochondrial genomes of euglenozoans. BMC Biol 2021; 19:103. [PMID: 34001130 PMCID: PMC8130358 DOI: 10.1186/s12915-021-01035-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/22/2021] [Indexed: 12/28/2022] Open
Abstract
Background The supergroup Euglenozoa unites heterotrophic flagellates from three major clades, kinetoplastids, diplonemids, and euglenids, each of which exhibits extremely divergent mitochondrial characteristics. Mitochondrial genomes (mtDNAs) of euglenids comprise multiple linear chromosomes carrying single genes, whereas mitochondrial chromosomes are circular non-catenated in diplonemids, but circular and catenated in kinetoplastids. In diplonemids and kinetoplastids, mitochondrial mRNAs require extensive and diverse editing and/or trans-splicing to produce mature transcripts. All known euglenozoan mtDNAs exhibit extremely short mitochondrial small (rns) and large (rnl) subunit rRNA genes, and absence of tRNA genes. How these features evolved from an ancestral bacteria-like circular mitochondrial genome remains unanswered. Results We sequenced and assembled 20 euglenozoan single-cell amplified genomes (SAGs). In our phylogenetic and phylogenomic analyses, three SAGs were placed within kinetoplastids, 14 within diplonemids, one (EU2) within euglenids, and two SAGs with nearly identical small subunit rRNA gene (18S) sequences (EU17/18) branched as either a basal lineage of euglenids, or as a sister to all euglenozoans. Near-complete mitochondrial genomes were identified in EU2 and EU17/18. Surprisingly, both EU2 and EU17/18 mitochondrial contigs contained multiple genes and one tRNA gene. Furthermore, EU17/18 mtDNA possessed several features unique among euglenozoans including full-length rns and rnl genes, six mitoribosomal genes, and nad11, all likely on a single chromosome. Conclusions Our data strongly suggest that EU17/18 is an early-branching euglenozoan with numerous ancestral mitochondrial features. Collectively these data contribute to untangling the early evolution of euglenozoan mitochondria. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-021-01035-y.
Collapse
Affiliation(s)
- Kristína Záhonová
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic.,Faculty of Science, Charles University, BIOCEV, Vestec, Czech Republic
| | - Gordon Lax
- Department of Botany, University of British Columbia, Vancouver, Canada
| | - Savar D Sinha
- Center for Mechanisms of Evolution, Biodesign Institute, School of Life Sciences, Arizona State University, Tempe, USA
| | - Guy Leonard
- Department of Zoology, University of Oxford, Oxford, UK
| | | | - Julius Lukeš
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice (Budweis), Czech Republic. .,Faculty of Sciences, University of South Bohemia, České Budějovice (Budweis), Czech Republic.
| | - Jeremy G Wideman
- Center for Mechanisms of Evolution, Biodesign Institute, School of Life Sciences, Arizona State University, Tempe, USA.
| |
Collapse
|
31
|
Tobiasson V, Gahura O, Aibara S, Baradaran R, Zíková A, Amunts A. Interconnected assembly factors regulate the biogenesis of mitoribosomal large subunit. EMBO J 2021; 40:e106292. [PMID: 33576519 PMCID: PMC7957421 DOI: 10.15252/embj.2020106292] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 12/18/2020] [Accepted: 12/23/2020] [Indexed: 12/11/2022] Open
Abstract
Mitoribosomes consist of ribosomal RNA and protein components, coordinated assembly of which is critical for function. We used mitoribosomes from Trypanosoma brucei with reduced RNA and increased protein mass to provide insights into the biogenesis of the mitoribosomal large subunit. Structural characterization of a stable assembly intermediate revealed 22 assembly factors, some of which have orthologues/counterparts/homologues in mammalian genomes. These assembly factors form a protein network that spans a distance of 180 Å, shielding the ribosomal RNA surface. The central protuberance and L7/L12 stalk are not assembled entirely and require removal of assembly factors and remodeling of the mitoribosomal proteins to become functional. The conserved proteins GTPBP7 and mt‐EngA are bound together at the subunit interface in proximity to the peptidyl transferase center. A mitochondrial acyl‐carrier protein plays a role in docking the L1 stalk, which needs to be repositioned during maturation. Additional enzymatically deactivated factors scaffold the assembly while the exit tunnel is blocked. Together, this extensive network of accessory factors stabilizes the immature sites and connects the functionally important regions of the mitoribosomal large subunit.
Collapse
Affiliation(s)
- Victor Tobiasson
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
| | - Ondřej Gahura
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic
| | - Shintaro Aibara
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
| | - Rozbeh Baradaran
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
| | - Alena Zíková
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, Ceske Budejovice, Czech Republic.,Faculty of Science, University of South Bohemia, Ceske Budejovice, Czech Republic
| | - Alexey Amunts
- Science for Life Laboratory, Department of Biochemistry and Biophysics, Stockholm University, Solna, Sweden
| |
Collapse
|
32
|
Ferrari A, Del'Olio S, Barrientos A. The Diseased Mitoribosome. FEBS Lett 2020; 595:1025-1061. [PMID: 33314036 DOI: 10.1002/1873-3468.14024] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/03/2020] [Accepted: 12/06/2020] [Indexed: 12/17/2022]
Abstract
Mitochondria control life and death in eukaryotic cells. Harboring a unique circular genome, a by-product of an ancient endosymbiotic event, mitochondria maintains a specialized and evolutionary divergent protein synthesis machinery, the mitoribosome. Mitoribosome biogenesis depends on elements encoded in both the mitochondrial genome (the RNA components) and the nuclear genome (all ribosomal proteins and assembly factors). Recent cryo-EM structures of mammalian mitoribosomes have illuminated their composition and provided hints regarding their assembly and elusive mitochondrial translation mechanisms. A growing body of literature involves the mitoribosome in inherited primary mitochondrial disorders. Mutations in genes encoding mitoribosomal RNAs, proteins, and assembly factors impede mitoribosome biogenesis, causing protein synthesis defects that lead to respiratory chain failure and mitochondrial disorders such as encephalo- and cardiomyopathy, deafness, neuropathy, and developmental delays. In this article, we review the current fundamental understanding of mitoribosome assembly and function, and the clinical landscape of mitochondrial disorders driven by mutations in mitoribosome components and assembly factors, to portray how basic and clinical studies combined help us better understand both mitochondrial biology and medicine.
Collapse
Affiliation(s)
- Alberto Ferrari
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA
| | - Samuel Del'Olio
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA.,Molecular and Cellular Pharmacology Graduate Program, University of Miami Miller School of Medicine, FL, USA
| | - Antoni Barrientos
- Department of Neurology, University of Miami Miller School of Medicine, FL, USA.,Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, FL, USA
| |
Collapse
|