1
|
Xu F, Suyama R, Inada T, Kawaguchi S, Kai T. HemK2 functions for sufficient protein synthesis and RNA stability through eRF1 methylation during Drosophila oogenesis. Development 2024; 151:dev202795. [PMID: 38881530 DOI: 10.1242/dev.202795] [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: 02/17/2024] [Accepted: 06/07/2024] [Indexed: 06/18/2024]
Abstract
HemK2 is a highly conserved methyltransferase, but the identification of its genuine substrates has been controversial, and its biological importance in higher organisms remains unclear. We elucidate the role of HemK2 in the methylation of eukaryotic Release Factor 1 (eRF1), a process that is essential for female germline development in Drosophila melanogaster. Knockdown of hemK2 in the germline cells (hemK2-GLKD) induces apoptosis, accompanied by a pronounced decrease in both eRF1 methylation and protein synthesis. Overexpression of a methylation-deficient eRF1 variant recapitulates the defects observed in hemK2-GLKD, suggesting that eRF1 is a primary methylation target of HemK2. Furthermore, hemK2-GLKD leads to a significant reduction in mRNA levels in germline cell. These defects in oogenesis and protein synthesis can be partially restored by inhibiting the No-Go Decay pathway. In addition, hemK2 knockdown is associated with increased disome formation, suggesting that disruptions in eRF1 methylation may provoke ribosomal stalling, which subsequently activates translation-coupled mRNA surveillance mechanisms that degrade actively translated mRNAs. We propose that HemK2-mediated methylation of eRF1 is crucial for ensuring efficient protein production and mRNA stability, which are vital for the generation of high-quality eggs.
Collapse
Affiliation(s)
- Fengmei Xu
- Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
| | - Ritsuko Suyama
- Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
| | - Toshifumi Inada
- Division of RNA and Gene regulation, Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan
| | - Shinichi Kawaguchi
- Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
| | - Toshie Kai
- Graduate School of Frontier Biosciences, Osaka University, Osaka 565-0871, Japan
| |
Collapse
|
2
|
Mutso M, Brūmele B, Serova E, Väärtnõu F, Suija M, Kurg R. The methyltransferase N6AMT1 participates in the cell cycle by regulating cyclin E levels. PLoS One 2024; 19:e0298884. [PMID: 38394175 PMCID: PMC10889616 DOI: 10.1371/journal.pone.0298884] [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: 08/30/2023] [Accepted: 01/31/2024] [Indexed: 02/25/2024] Open
Abstract
The methyltransferase N6AMT1 has been associated with the progression of different pathological conditions, such as tumours and neurological malfunctions, but the underlying mechanism is not fully understood. Analysis of N6AMT1-depleted cells revealed that N6AMT1 is involved in the cell cycle and cell proliferation. In N6AMT1-depleted cells, the cell doubling time was increased, and cell progression out of mitosis and the G0/G1 and S phases was disrupted. It was discovered that in N6AMT1-depleted cells, the transcription of cyclin E was downregulated, which indicates that N6AMT1 is involved in the regulation of cyclin E transcription. Understanding the functions and importance of N6AMT1 in cell proliferation and cell cycle regulation is essential for developing treatments and strategies to control diseases that are associated with N6AMT1.
Collapse
Affiliation(s)
- Margit Mutso
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Baiba Brūmele
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Evgeniia Serova
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Fred Väärtnõu
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Mihkel Suija
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Reet Kurg
- Institute of Technology, University of Tartu, Tartu, Estonia
| |
Collapse
|
3
|
Weirich S, Ulu GT, Chandrasekaran TT, Kehl J, Schmid J, Dorscht F, Kublanovsky M, Levy D, Jeltsch A. Distinct specificities of the HEMK2 protein methyltransferase in methylation of glutamine and lysine residues. Protein Sci 2024; 33:e4897. [PMID: 38284488 PMCID: PMC10804810 DOI: 10.1002/pro.4897] [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: 10/18/2023] [Revised: 12/18/2023] [Accepted: 12/31/2023] [Indexed: 01/30/2024]
Abstract
The HEMK2 protein methyltransferase has been described as glutamine methyltransferase catalyzing ERF1-Q185me1 and lysine methyltransferase catalyzing H4K12me1. Methylation of two distinct target residues is unique for this class of enzymes. To understand the specific catalytic adaptations of HEMK2 allowing it to master this chemically challenging task, we conducted a detailed investigation of the substrate sequence specificities of HEMK2 for Q- and K-methylation. Our data show that HEMK2 prefers methylation of Q over K at peptide and protein level. Moreover, the ERF1 sequence is strongly preferred as substrate over the H4K12 sequence. With peptide SPOT array methylation experiments, we show that Q-methylation preferentially occurs in a G-Q-X3 -R context, while K-methylation prefers S/T at the first position of the motif. Based on this, we identified novel HEMK2 K-methylation peptide substrates with sequences taken from human proteins which are methylated with high activity. Since H4K12 methylation by HEMK2 was very low, other protein lysine methyltransferases were examined for their ability to methylate the H4K12 site. We show that SETD6 has a high H4K12me1 methylation activity (about 1000-times stronger than HEMK2) and this enzyme is mainly responsible for H4K12me1 in DU145 prostate cancer cells.
Collapse
Affiliation(s)
- Sara Weirich
- Institute of Biochemistry and Technical Biochemistry, Department of BiochemistryUniversity of StuttgartStuttgartGermany
| | - Gizem T. Ulu
- Institute of Biochemistry and Technical Biochemistry, Department of BiochemistryUniversity of StuttgartStuttgartGermany
| | - Thyagarajan T. Chandrasekaran
- Institute of Biochemistry and Technical Biochemistry, Department of BiochemistryUniversity of StuttgartStuttgartGermany
| | - Jana Kehl
- Institute of Biochemistry and Technical Biochemistry, Department of BiochemistryUniversity of StuttgartStuttgartGermany
| | - Jasmin Schmid
- Institute of Biochemistry and Technical Biochemistry, Department of BiochemistryUniversity of StuttgartStuttgartGermany
| | - Franziska Dorscht
- Institute of Biochemistry and Technical Biochemistry, Department of BiochemistryUniversity of StuttgartStuttgartGermany
| | - Margarita Kublanovsky
- The Shraga Segal Department of Microbiology, Immunology and GeneticsBen‐Gurion University of the NegevBe'er‐ShevaIsrael
- The National Institute for Biotechnology in the NegevBen‐Gurion University of the NegevBe'er‐ShevaIsrael
| | - Dan Levy
- The Shraga Segal Department of Microbiology, Immunology and GeneticsBen‐Gurion University of the NegevBe'er‐ShevaIsrael
- The National Institute for Biotechnology in the NegevBen‐Gurion University of the NegevBe'er‐ShevaIsrael
| | - Albert Jeltsch
- Institute of Biochemistry and Technical Biochemistry, Department of BiochemistryUniversity of StuttgartStuttgartGermany
| |
Collapse
|
4
|
Chambard M, Albert B, Cadiou M, Auby S, Profizi C, Boulogne I. Living yeast-based biostimulants: different genes for the same results? FRONTIERS IN PLANT SCIENCE 2023; 14:1171564. [PMID: 37404542 PMCID: PMC10315835 DOI: 10.3389/fpls.2023.1171564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 05/31/2023] [Indexed: 07/06/2023]
Abstract
Nowadays, many products are available in the plant biostimulants market. Among them, living yeast-based biostimulants are also commercialized. Given the living aspect of these last products, the reproducibility of their effects should be investigated to ensure end-users' confidence. Therefore, this study aimed to compare the effects of a living yeast-based biostimulant between two different soybean cultures. These two cultures named C1 and C2 were conducted on the same variety and soil but in different locations and dates until the VC developmental stage (unifoliate leaves unrolled), with Bradyrhizobium japonicum (control and Bs condition) and with and without biostimulant coating seed treatment. The foliar transcriptomic analysis done first showed a high gene expression difference between the two cultures. Despite this first result, a secondary analysis seemed to show that this biostimulant led to a similar pathway enhancement in plants and with common genes even if the expressed genes were different between the two cultures. The pathways which seem to be reproducibly impacted by this living yeast-based biostimulant are abiotic stress tolerance and cell wall/carbohydrate synthesis. Impacting these pathways may protect the plant from abiotic stresses and maintain a higher level of sugars in plant.
Collapse
Affiliation(s)
- Marie Chambard
- Univ Rouen Normandie, GLYCOMEV UR 4358, SFR Normandie Végétal FED 4277, Innovation Chimie Carnot, IRIB, Rouen, France
| | | | | | - Sarah Auby
- Agrauxine by Lesaffre, Beaucouzé, France
| | | | - Isabelle Boulogne
- Univ Rouen Normandie, GLYCOMEV UR 4358, SFR Normandie Végétal FED 4277, Innovation Chimie Carnot, IRIB, Rouen, France
| |
Collapse
|
5
|
Biziaev NS, Shuvalov AV, Alkalaeva EZ. HEMK-Like Methyltransferases in the Regulation of Cellular Processes. Mol Biol 2022. [DOI: 10.1134/s0026893322030025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
6
|
Rudenko AY, Mariasina SS, Sergiev PV, Polshakov VI. Analogs of S-Adenosyl-L-Methionine in Studies of Methyltransferases. Mol Biol 2022; 56:229-250. [PMID: 35440827 PMCID: PMC9009987 DOI: 10.1134/s002689332202011x] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/18/2021] [Accepted: 10/20/2021] [Indexed: 01/02/2023]
Abstract
Methyltransferases (MTases) play an important role in the functioning of living systems, catalyzing the methylation reactions of DNA, RNA, proteins, and small molecules, including endogenous compounds and drugs. Many human diseases are associated with disturbances in the functioning of these enzymes; therefore, the study of MTases is an urgent and important task. Most MTases use the cofactor S‑adenosyl‑L‑methionine (SAM) as a methyl group donor. SAM analogs are widely applicable in the study of MTases: they are used in studies of the catalytic activity of these enzymes, in identification of substrates of new MTases, and for modification of the substrates or substrate linking to MTases. In this review, new synthetic analogs of SAM and the problems that can be solved with their usage are discussed.
Collapse
Affiliation(s)
- A. Yu. Rudenko
- Faculty of Fundamental Medicine, Moscow State University, 119991 Moscow, Russia
- Zelinsky Institute of Organic Chemistry, 119991 Moscow, Russia
| | - S. S. Mariasina
- Faculty of Fundamental Medicine, Moscow State University, 119991 Moscow, Russia
- Institute of Functional Genomics, Moscow State University, 119991 Moscow, Russia
| | - P. V. Sergiev
- Institute of Functional Genomics, Moscow State University, 119991 Moscow, Russia
| | - V. I. Polshakov
- Faculty of Fundamental Medicine, Moscow State University, 119991 Moscow, Russia
| |
Collapse
|
7
|
Shi Y, Yang X, Ye X, Feng J, Cheng T, Zhou X, Liu DX, Xu L, Wang J. The Methyltransferase HemK Regulates the Virulence and Nutrient Utilization of the Phytopathogenic Bacterium Xanthomonas citri Subsp. citri. Int J Mol Sci 2022; 23:ijms23073931. [PMID: 35409293 PMCID: PMC8999716 DOI: 10.3390/ijms23073931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2022] [Revised: 03/28/2022] [Accepted: 03/30/2022] [Indexed: 11/18/2022] Open
Abstract
Citrus canker, caused by the bacterium Xanthomonas citri subsp. citri (Xcc), seriously affects fruit quality and yield, leading to significant economic losses around the world. Understanding the mechanism of Xcc virulence is important for the effective control of Xcc infection. In this report, we investigate the role of a protein named HemK in the regulation of the virulence traits of Xcc. The hemK gene was deleted in the Xcc jx-6 background, and the ΔhemK mutant phenotypically displayed significantly decreased motility, biofilm formation, extracellular enzymes, and polysaccharides production, as well as increased sensitivity to oxidative stress and high temperatures. In accordance with the role of HemK in the regulation of a variety of virulence-associated phenotypes, the deletion of hemK resulted in reduced virulence on citrus plants as well as a compromised hypersensitive response on a non-host plant, Nicotiana benthamiana. These results indicated that HemK is required for the virulence of Xcc. To characterize the regulatory effect of hemK deletion on gene expression, RNA sequencing analysis was conducted using the wild-type Xcc jx-6 strain and its isogenic ΔhemK mutant strain, grown in XVM2 medium. Comparative transcriptome analysis of these two strains revealed that hemK deletion specifically changed the expression of several virulence-related genes associated with the bacterial secretion system, chemotaxis, and quorum sensing, and the expression of various genes related to nutrient utilization including amino acid metabolism, carbohydrate metabolism, and energy metabolism. In conclusion, our results indicate that HemK plays an essential role in virulence, the regulation of virulence factor synthesis, and the nutrient utilization of Xcc.
Collapse
Affiliation(s)
- Yu Shi
- Integrative Microbiology Research Centre, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; (Y.S.); (X.Y.); (X.Y.); (J.F.); (T.C.); (X.Z.); (D.X.L.)
| | - Xiaobei Yang
- Integrative Microbiology Research Centre, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; (Y.S.); (X.Y.); (X.Y.); (J.F.); (T.C.); (X.Z.); (D.X.L.)
| | - Xiaoxin Ye
- Integrative Microbiology Research Centre, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; (Y.S.); (X.Y.); (X.Y.); (J.F.); (T.C.); (X.Z.); (D.X.L.)
| | - Jiaying Feng
- Integrative Microbiology Research Centre, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; (Y.S.); (X.Y.); (X.Y.); (J.F.); (T.C.); (X.Z.); (D.X.L.)
| | - Tianfang Cheng
- Integrative Microbiology Research Centre, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; (Y.S.); (X.Y.); (X.Y.); (J.F.); (T.C.); (X.Z.); (D.X.L.)
| | - Xiaofan Zhou
- Integrative Microbiology Research Centre, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; (Y.S.); (X.Y.); (X.Y.); (J.F.); (T.C.); (X.Z.); (D.X.L.)
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China
| | - Ding Xiang Liu
- Integrative Microbiology Research Centre, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; (Y.S.); (X.Y.); (X.Y.); (J.F.); (T.C.); (X.Z.); (D.X.L.)
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China
| | - Linghui Xu
- Integrative Microbiology Research Centre, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; (Y.S.); (X.Y.); (X.Y.); (J.F.); (T.C.); (X.Z.); (D.X.L.)
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China
- Correspondence: (L.X.); (J.W.)
| | - Junxia Wang
- Integrative Microbiology Research Centre, College of Plant Protection, South China Agricultural University, Guangzhou 510642, China; (Y.S.); (X.Y.); (X.Y.); (J.F.); (T.C.); (X.Z.); (D.X.L.)
- Guangdong Province Key Laboratory of Microbial Signals and Disease Control, South China Agricultural University, Guangzhou 510642, China
- Correspondence: (L.X.); (J.W.)
| |
Collapse
|
8
|
Mammalian HEMK1 methylates glutamine residue of the GGQ motif of mitochondrial release factors. Sci Rep 2022; 12:4104. [PMID: 35260756 PMCID: PMC8904536 DOI: 10.1038/s41598-022-08061-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 03/01/2022] [Indexed: 02/04/2023] Open
Abstract
Despite limited reports on glutamine methylation, methylated glutamine is found to be highly conserved in a "GGQ" motif in both prokaryotes and eukaryotes. In bacteria, glutamine methylation of peptide chain release factors 1/2 (RF1/2) by the enzyme PrmC is essential for translational termination and transcript recycling. Two PrmC homologs, HEMK1 and HEMK2, are found in mammals. In contrast to those of HEMK2, the biochemical properties and biological significance of HEMK1 remain largely unknown. In this study, we demonstrated that HEMK1 is an active methyltransferase for the glutamine residue of the GGQ motif of all four putative mitochondrial release factors (mtRFs)-MTRF1, MTRF1L, MRPL58, and MTRFR. In HEMK1-deficient HeLa cells, GGQ motif glutamine methylation was absent in all the mtRFs. We examined cell growth and mitochondrial properties, but disruption of the HEMK1 gene had no considerable impact on the overall cell growth, mtDNA copy number, mitochondrial membrane potential, and mitochondrial protein synthesis under regular culture condition with glucose as a carbon source. Furthermore, cell growth potential of HEMK1 KO cells was still maintained in the respiratory condition with galactose medium. Our results suggest that HEMK1 mediates the GGQ methylation of all four mtRFs in human cells; however, this specific modification seems mostly dispensable in cell growth and mitochondrial protein homeostasis at least for HeLa cells under fermentative culture condition.
Collapse
|
9
|
Małecki JM, Davydova E, Falnes PØ. Protein methylation in mitochondria. J Biol Chem 2022; 298:101791. [PMID: 35247388 PMCID: PMC9006661 DOI: 10.1016/j.jbc.2022.101791] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 02/18/2022] [Accepted: 02/22/2022] [Indexed: 12/15/2022] Open
Abstract
Many proteins are modified by posttranslational methylation, introduced by a number of methyltransferases (MTases). Protein methylation plays important roles in modulating protein function and thus in optimizing and regulating cellular and physiological processes. Research has mainly focused on nuclear and cytosolic protein methylation, but it has been known for many years that also mitochondrial proteins are methylated. During the last decade, significant progress has been made on identifying the MTases responsible for mitochondrial protein methylation and addressing its functional significance. In particular, several novel human MTases have been uncovered that methylate lysine, arginine, histidine, and glutamine residues in various mitochondrial substrates. Several of these substrates are key components of the bioenergetics machinery, e.g., respiratory Complex I, citrate synthase, and the ATP synthase. In the present review, we report the status of the field of mitochondrial protein methylation, with a particular emphasis on recently discovered human MTases. We also discuss evolutionary aspects and functional significance of mitochondrial protein methylation and present an outlook for this emergent research field.
Collapse
Affiliation(s)
- Jędrzej M Małecki
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway.
| | - Erna Davydova
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway
| | - Pål Ø Falnes
- Department of Biosciences, Faculty of Mathematics and Natural Sciences, University of Oslo, 0316 Oslo, Norway.
| |
Collapse
|
10
|
Mullally CA, Mikucki A, Wise MJ, Kahler CM. Modelling evolutionary pathways for commensalism and hypervirulence in Neisseria meningitidis. Microb Genom 2021; 7. [PMID: 34704920 PMCID: PMC8627216 DOI: 10.1099/mgen.0.000662] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Neisseria meningitidis, the meningococcus, resides exclusively in humans and causes invasive meningococcal disease (IMD). The population of N. meningitidis is structured into stable clonal complexes by limited horizontal recombination in this naturally transformable species. N. meningitidis is an opportunistic pathogen, with some clonal complexes, such as cc53, effectively acting as commensal colonizers, while other genetic lineages, such as cc11, are rarely colonizers but are over-represented in IMD and are termed hypervirulent. This study examined theoretical evolutionary pathways for pathogenic and commensal lineages by examining the prevalence of horizontally acquired genomic islands (GIs) and loss-of-function (LOF) mutations. Using a collection of 4850 genomes from the BIGSdb database, we identified 82 GIs in the pan-genome of 11 lineages (10 hypervirulent and one commensal lineage). A new computational tool, Phaser, was used to identify frameshift mutations, which were examined for statistically significant association with genetic lineage. Phaser identified a total of 144 frameshift loci of which 105 were shown to have a statistically significant non-random distribution in phase status. The 82 GIs, but not the LOF loci, were associated with genetic lineage and invasiveness using the disease carriage ratio metric. These observations have been integrated into a new model that infers the early events of the evolution of the human adapted meningococcus. These pathways are enriched for GIs that are involved in modulating attachment to the host, growth rate, iron uptake and toxin expression which are proposed to increase competition within the meningococcal population for the limited environmental niche of the human nasopharynx. We surmise that competition for the host mucosal surface with the nasopharyngeal microbiome has led to the selection of isolates with traits that enable access to cell types (non-phagocytic and phagocytic) in the submucosal tissues leading to an increased risk for IMD.
Collapse
Affiliation(s)
- Christopher A. Mullally
- The Marshall Center for Infectious Diseases Research and Training, School of Biomedical Science, University of Western Australia, Perth, Australia
| | - August Mikucki
- The Marshall Center for Infectious Diseases Research and Training, School of Biomedical Science, University of Western Australia, Perth, Australia
| | - Michael J. Wise
- The Marshall Center for Infectious Diseases Research and Training, School of Biomedical Science, University of Western Australia, Perth, Australia
- School of Physics, Mathematics and Computing, University of Western Australia, Perth, Australia
| | - Charlene M. Kahler
- The Marshall Center for Infectious Diseases Research and Training, School of Biomedical Science, University of Western Australia, Perth, Australia
- Telethon Kids Institute, Perth Children’s Hospital, Perth, Australia
- *Correspondence: Charlene M. Kahler,
| |
Collapse
|
11
|
Abstract
The two-component system PhoP/PhoQ is essential for Salmonella enterica serovar Typhimurium virulence. Here, we report that PhoP is methylated extensively. Two consecutive glutamate (E) and aspartate (D)/E residues, i.e., E8/D9 and E107/E108, and arginine (R) 112 can be methylated. Individual mutation of these above-mentioned residues caused impaired phosphorylation and dimerization or DNA-binding ability of PhoP to a different extent and led to attenuated bacterial virulence. With the help of specific antibodies recognizing methylated E8 and monomethylated R112, we found that the methylation levels of E8 or R112 decreased dramatically when bacteria encountered low magnesium, acidic pH, or phagocytosis by macrophages, under which PhoP can be activated. Furthermore, CheR, a bacterial chemotaxis methyltransferase, was identified to methylate R112. Overexpression of cheR decreased PhoP activity but increased PhoP stability. Together, the current study reveals that methylation plays an important role in regulating PhoP activities in response to environmental cues and, consequently, modulates Salmonella virulence.
Collapse
|
12
|
Balasanyants SM, Aleksandrova EV, Polikanov YS. The Role of Release Factors in the Hydrolysis of Ester Bond in Peptidyl-tRNA. BIOCHEMISTRY (MOSCOW) 2021; 86:1122-1127. [PMID: 34565315 DOI: 10.1134/s0006297921090078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Class I release factors (RFs) recognize stop codons in the sequences of mRNAs and are required for the hydrolysis of peptidyl-tRNA in the ribosomal P site during the final step of protein synthesis in bacteria, resulting in the release of a complete polypeptide chain from the ribosome. A key role in this process belongs to the highly conserved GGQ motif in RFs. Mutations in this motif can reduce the hydrolysis rate or even completely inhibit the reaction. Previously, it was hypothesized that the amino acid residues of GGQ (especially glutamine) are essential for the proper coordination of the water molecule for subsequent hydrolysis of the ester bond. However, available structures of the 70S ribosome termination complex do not allow unambiguous identification of the exact orientation of the carbonyl group in peptidyl-tRNA relative to the GGQ, as well as of the position of the catalytic water molecule in the peptidyl transferase center (PTC). This mini-review summarizes key facts and hypotheses on the role of GGQ in the catalysis of peptide release, as well as suggests and discusses future experiments aimed to produce high-quality structural data for deciphering the precise mechanism of RF-mediated catalysis.
Collapse
Affiliation(s)
- Samson M Balasanyants
- Department of Biological Sciences, College of Liberal Arts and Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Elena V Aleksandrova
- Department of Biological Sciences, College of Liberal Arts and Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Yury S Polikanov
- Department of Biological Sciences, College of Liberal Arts and Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA.
| |
Collapse
|
13
|
Pundir S, Ge X, Sanyal S. GGQ methylation enhances both speed and accuracy of stop codon recognition by bacterial class-I release factors. J Biol Chem 2021; 296:100681. [PMID: 33887323 PMCID: PMC8131318 DOI: 10.1016/j.jbc.2021.100681] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 04/13/2021] [Accepted: 04/16/2021] [Indexed: 10/28/2022] Open
Abstract
Accurate translation termination in bacteria requires correct recognition of the stop codons by the class-I release factors (RFs) RF1 and RF2, which release the nascent peptide from the peptidyl tRNA after undergoing a "compact to open" conformational transition. These RFs possess a conserved Gly-Gly-Gln (GGQ) peptide release motif, of which the Q residue is posttranslationally methylated. GGQ-methylated RFs have been shown to be faster in peptide release than the unmethylated ones, but it was unknown whether this modification had additional roles. Using a fluorescence-based real-time in vitro translation termination assay in a stopped-flow instrument, we demonstrate that methylated RF1 and RF2 are two- to four-fold more accurate in the cognate stop codon recognition than their unmethylated variants. Using pH titration, we show that the lack of GGQ methylation facilitates the "compact to open" transition, which results in compromised accuracy of the unmethylated RFs. Furthermore, thermal melting studies using circular dichroism and SYPRO-orange fluorescence demonstrate that GGQ methylation increases overall stability of the RF proteins. This increased stability, we suspect, is the basis for the more controlled conformational change of the methylated RFs upon codon recognition, which enhances both their speed and accuracy. This GGQ methylation-based modulation of the accuracy of RFs can be a tool for regulating translational termination in vivo.
Collapse
Affiliation(s)
- Shreya Pundir
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Xueliang Ge
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Uppsala, Sweden
| | - Suparna Sanyal
- Department of Cell and Molecular Biology, Biomedical Center, Uppsala University, Uppsala, Sweden.
| |
Collapse
|
14
|
Lalanne J, Parker DJ, Li G. Spurious regulatory connections dictate the expression-fitness landscape of translation factors. Mol Syst Biol 2021; 17:e10302. [PMID: 33900014 PMCID: PMC8073009 DOI: 10.15252/msb.202110302] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 03/12/2021] [Accepted: 03/16/2021] [Indexed: 12/21/2022] Open
Abstract
During steady-state cell growth, individual enzymatic fluxes can be directly inferred from growth rate by mass conservation, but the inverse problem remains unsolved. Perturbing the flux and expression of a single enzyme could have pleiotropic effects that may or may not dominate the impact on cell fitness. Here, we quantitatively dissect the molecular and global responses to varied expression of translation termination factors (peptide release factors, RFs) in the bacterium Bacillus subtilis. While endogenous RF expression maximizes proliferation, deviations in expression lead to unexpected distal regulatory responses that dictate fitness reduction. Molecularly, RF depletion causes expression imbalance at specific operons, which activates master regulators and detrimentally overrides the transcriptome. Through these spurious connections, RF abundances are thus entrenched by focal points within the regulatory network, in one case located at a single stop codon. Such regulatory entrenchment suggests that predictive bottom-up models of expression-fitness landscapes will require near-exhaustive characterization of parts.
Collapse
Affiliation(s)
- Jean‐Benoît Lalanne
- Department of BiologyMassachusetts Institute of TechnologyCambridgeMAUSA
- Department of PhysicsMassachusetts Institute of TechnologyCambridgeMAUSA
- Present address:
Department of Genome SciencesUniversity of WashingtonSeattleWAUSA
| | - Darren J Parker
- Department of BiologyMassachusetts Institute of TechnologyCambridgeMAUSA
- Present address:
Biosciences DivisionOak Ridge National LaboratoryOak RidgeTNUSA
| | - Gene‐Wei Li
- Department of BiologyMassachusetts Institute of TechnologyCambridgeMAUSA
| |
Collapse
|
15
|
Structural insight into HEMK2-TRMT112-mediated glutamine methylation. Biochem J 2021; 477:3833-3838. [PMID: 32969463 DOI: 10.1042/bcj20200594] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/09/2020] [Accepted: 09/24/2020] [Indexed: 02/02/2023]
Abstract
Post-translational modifications play important roles in mediating protein functions in a wide variety of cellular events in vivo. HEMK2-TRMT112 heterodimer has been reported to be responsible for both histone lysine methylation and eukaryotic release factor 1 (eRF1) glutamine methylation. However, how HEMK2-TRMT112 complex recognizes and catalyzes eRF1 glutamine methylation is largely unknown. Here, we present two structures of HEMK2-TRMT112, with one bound to SAM and the other bound with SAH and methylglutamine (Qme). Structural analyses of the post-catalytic complex, complemented by mass spectrometry experiments, indicate that the HEMK2 utilizes a specific pocket to accommodate the substrate glutamine and catalyzes the subsequent methylation. Therefore, our work not only throws light on the protein glutamine methylation mechanism, but also reveals the dual activity of HEMK2 by catalyzing the methylation of both Lys and Gln residues.
Collapse
|
16
|
Lacoux C, Wacheul L, Saraf K, Pythoud N, Huvelle E, Figaro S, Graille M, Carapito C, Lafontaine DLJ, Heurgué-Hamard V. The catalytic activity of the translation termination factor methyltransferase Mtq2-Trm112 complex is required for large ribosomal subunit biogenesis. Nucleic Acids Res 2020; 48:12310-12325. [PMID: 33166396 PMCID: PMC7708063 DOI: 10.1093/nar/gkaa972] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 10/05/2020] [Accepted: 10/09/2020] [Indexed: 01/14/2023] Open
Abstract
The Mtq2-Trm112 methyltransferase modifies the eukaryotic translation termination factor eRF1 on the glutamine side chain of a universally conserved GGQ motif that is essential for release of newly synthesized peptides. Although this modification is found in the three domains of life, its exact role in eukaryotes remains unknown. As the deletion of MTQ2 leads to severe growth impairment in yeast, we have investigated its role further and tested its putative involvement in ribosome biogenesis. We found that Mtq2 is associated with nuclear 60S subunit precursors, and we demonstrate that its catalytic activity is required for nucleolar release of pre-60S and for efficient production of mature 5.8S and 25S rRNAs. Thus, we identify Mtq2 as a novel ribosome assembly factor important for large ribosomal subunit formation. We propose that Mtq2-Trm112 might modify eRF1 in the nucleus as part of a quality control mechanism aimed at proof-reading the peptidyl transferase center, where it will subsequently bind during translation termination.
Collapse
Affiliation(s)
- Caroline Lacoux
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Ludivine Wacheul
- RNA Molecular Biology, Fonds de la Recherche Scientifique (F.R.S.-FNRS), Université Libre de Bruxelles Cancer Research Center (U-CRC), Center for Microscopy and Molecular Imaging (CMMI), Gosselies, Belgium
| | - Kritika Saraf
- RNA Molecular Biology, Fonds de la Recherche Scientifique (F.R.S.-FNRS), Université Libre de Bruxelles Cancer Research Center (U-CRC), Center for Microscopy and Molecular Imaging (CMMI), Gosselies, Belgium
| | - Nicolas Pythoud
- Laboratoire de Spectrométrie de Masse Bio-Organique (LSMBO), UMR 7178, IPHC, Université de Strasbourg, CNRS, Strasbourg, France
| | - Emmeline Huvelle
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Sabine Figaro
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Marc Graille
- Laboratoire de Biologie Structurale de la Cellule (BIOC), CNRS, Ecole polytechnique, Institut Polytechnique de Paris, F-91128 Palaiseau, France
| | - Christine Carapito
- Laboratoire de Spectrométrie de Masse Bio-Organique (LSMBO), UMR 7178, IPHC, Université de Strasbourg, CNRS, Strasbourg, France
| | - Denis L J Lafontaine
- RNA Molecular Biology, Fonds de la Recherche Scientifique (F.R.S.-FNRS), Université Libre de Bruxelles Cancer Research Center (U-CRC), Center for Microscopy and Molecular Imaging (CMMI), Gosselies, Belgium
| | - Valérie Heurgué-Hamard
- UMR8261 (CNRS, Université de Paris), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| |
Collapse
|
17
|
Woodcock CB, Horton JR, Zhang X, Blumenthal RM, Cheng X. Beta class amino methyltransferases from bacteria to humans: evolution and structural consequences. Nucleic Acids Res 2020; 48:10034-10044. [PMID: 32453412 PMCID: PMC7544214 DOI: 10.1093/nar/gkaa446] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 05/12/2020] [Accepted: 05/14/2020] [Indexed: 01/09/2023] Open
Abstract
S-adenosyl-l-methionine dependent methyltransferases catalyze methyl transfers onto a wide variety of target molecules, including DNA and RNA. We discuss a family of methyltransferases, those that act on the amino groups of adenine or cytosine in DNA, have conserved motifs in a particular order in their amino acid sequence, and are referred to as class beta MTases. Members of this class include M.EcoGII and M.EcoP15I from Escherichia coli, Caulobacter crescentus cell cycle-regulated DNA methyltransferase (CcrM), the MTA1-MTA9 complex from the ciliate Oxytricha, and the mammalian MettL3-MettL14 complex. These methyltransferases all generate N6-methyladenine in DNA, with some members having activity on single-stranded DNA as well as RNA. The beta class of methyltransferases has a unique multimeric feature, forming either homo- or hetero-dimers, allowing the enzyme to use division of labor between two subunits in terms of substrate recognition and methylation. We suggest that M.EcoGII may represent an ancestral form of these enzymes, as its activity is independent of the nucleic acid type (RNA or DNA), its strandedness (single or double), and its sequence (aside from the target adenine).
Collapse
Affiliation(s)
- Clayton B Woodcock
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - John R Horton
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Xing Zhang
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Robert M Blumenthal
- Department of Medical Microbiology and Immunology, and Program in Bioinformatics, The University of Toledo College of Medicine and Life Sciences, Toledo, OH 43614, USA
| | - Xiaodong Cheng
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| |
Collapse
|
18
|
The Peptide Chain Release Factor Methyltransferase PrmC Influences the Pseudomonas aeruginosa PA14 Endo- and Exometabolome. Metabolites 2020; 10:metabo10100417. [PMID: 33080992 PMCID: PMC7650828 DOI: 10.3390/metabo10100417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 10/10/2020] [Accepted: 10/14/2020] [Indexed: 11/18/2022] Open
Abstract
Pseudomonas aeruginosa is one of the most important nosocomial pathogens and understanding its virulence is the key to effective control of P. aeruginosa infections. The regulatory network governing virulence factor production in P. aeruginosa is exceptionally complex. Previous studies have shown that the peptide chain release factor methyltransferase PrmC plays an important role in bacterial pathogenicity. Yet, the underlying molecular mechanism is incompletely understood. In this study, we used untargeted liquid and gas chromatography coupled to mass spectrometry to characterise the metabolome of a prmC defective P. aeruginosa PA14 strain in comparison with the corresponding strain complemented with prmC in trans. The comprehensive metabolomics data provided new insight into the influence of prmC on virulence and metabolism. prmC deficiency had broad effects on the endo- and exometabolome of P. aeruginosa PA14, with a marked decrease of the levels of aromatic compounds accompanied by reduced precursor supply from the shikimate pathway. Furthermore, a pronounced decrease of phenazine production was observed as well as lower abundance of alkylquinolones. Unexpectedly, the metabolomics data showed no prmC-dependent effect on rhamnolipid production and an increase in pyochelin levels. A putative virulence biomarker identified in a previous study was significantly less abundant in the prmC deficient strain.
Collapse
|
19
|
Saito K, Green R, Buskirk AR. Ribosome recycling is not critical for translational coupling in Escherichia coli. eLife 2020; 9:59974. [PMID: 32965213 PMCID: PMC7538156 DOI: 10.7554/elife.59974] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 09/22/2020] [Indexed: 12/23/2022] Open
Abstract
We used ribosome profiling to characterize the biological role of ribosome recycling factor (RRF) in Escherichia coli. As expected, RRF depletion leads to enrichment of post-termination 70S complexes in 3′-UTRs. We also observe that elongating ribosomes are unable to complete translation because they are blocked by non-recycled ribosomes at stop codons. Previous studies have suggested a role for recycling in translational coupling within operons; if a ribosome remains bound to an mRNA after termination, it may re-initiate downstream. We found, however, that RRF depletion did not significantly affect coupling efficiency in reporter assays or in ribosome density genome-wide. These findings argue that re-initiation is not a major mechanism of translational coupling in E. coli. Finally, RRF depletion has dramatic effects on the activity of ribosome rescue factors tmRNA and ArfA. Our results provide a global view of the effects of the loss of ribosome recycling on protein synthesis in E. coli.
Collapse
Affiliation(s)
- Kazuki Saito
- Department of Molecular Biology and Genetics, Baltimore, United States
| | - Rachel Green
- Department of Molecular Biology and Genetics, Baltimore, United States.,Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, United States
| | - Allen R Buskirk
- Department of Molecular Biology and Genetics, Baltimore, United States
| |
Collapse
|
20
|
Liu Y, Filiatrault MJ. Antibacterial activity and mode of action of potassium tetraborate tetrahydrate against soft-rot bacterial plant pathogens. MICROBIOLOGY-SGM 2020; 166:837-848. [PMID: 32639227 PMCID: PMC7654739 DOI: 10.1099/mic.0.000948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Bacterial soft rot caused by the bacteria Dickeya and Pectobacterium is a destructive disease of vegetables, as well as ornamental plants. Several management options exist to help control these pathogens. Because of the limited success of these approaches, there is a need for the development of alternative methods to reduce losses. In this study, we evaluated the effect of potassium tetraborate tetrahydrate (PTB) on the growth of six Dickeya and Pectobacterium spp. Disc diffusion assays showed that Dickeya spp. and Pectobacterium spp. differ in their sensitivity to PTB. Spontaneous PTB-resistant mutants of Pectobacterium were identified and further investigation of the mechanism of PTB resistance was conducted by full genome sequencing. Point mutations in genes cpdB and supK were found in a single Pectobacterium atrosepticum PTB-resistant mutant. Additionally, point mutations in genes prfB (synonym supK) and prmC were found in two independent Pectobacterium brasiliense PTB-resistant mutants. prfB and prmC encode peptide chain release factor 2 and its methyltransferase, respectively. We propose the disruption of translation activity due to PTB leads to Pectobacterium growth inhibition. The P. atrosepticum PTB-resistant mutant showed altered swimming motility. Disease severity was reduced for P. atrosepticum-inoculated potato stems sprayed with PTB. We discuss the potential risk of selecting for bacterial resistance to this chemical.
Collapse
Affiliation(s)
- Yingyu Liu
- Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
| | - Melanie J. Filiatrault
- Section of Plant Pathology and Plant-Microbe Biology, School of Integrative Plant Science, Cornell University, Ithaca, NY 14853, USA
- Emerging Pests and Pathogens Research Unit, Robert W. Holley Center for Agriculture and Health, Agricultural Research Service, United States Department of Agriculture, Ithaca, NY 14853, USA
- *Correspondence: Melanie J. Filiatrault,
| |
Collapse
|
21
|
Loss of a single methylation in 23S rRNA delays 50S assembly at multiple late stages and impairs translation initiation and elongation. Proc Natl Acad Sci U S A 2020; 117:15609-15619. [PMID: 32571953 DOI: 10.1073/pnas.1914323117] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Ribosome biogenesis is a complex process, and dozens of factors are required to facilitate and regulate the subunit assembly in bacteria. The 2'-O-methylation of U2552 in 23S rRNA by methyltransferase RrmJ is a crucial step in late-stage assembly of the 50S subunit. Its absence results in severe growth defect and marked accumulation of pre50S assembly intermediates. In the present work, we employed cryoelectron microscopy to characterize a set of late-stage pre50S particles isolated from an Escherichia coli ΔrrmJ strain. These assembly intermediates (solved at 3.2 to 3.8 Å resolution) define a collection of late-stage particles on a progressive assembly pathway. Apart from the absence of L16, L35, and L36, major structural differences between these intermediates and the mature 50S subunit are clustered near the peptidyl transferase center, such as H38, H68-71, and H89-93. In addition, the ribosomal A-loop of the mature 50S subunit from ΔrrmJ strain displays large local flexibility on nucleotides next to unmethylated U2552. Fast kinetics-based biochemical assays demonstrate that the ΔrrmJ 50S subunit is only 50% active and two times slower than the WT 50S subunit in rapid subunit association. While the ΔrrmJ 70S ribosomes show no defect in peptide bond formation, peptide release, and ribosome recycling, they translocate with 20% slower rate than the WT ribosomes in each round of elongation. These defects amplify during synthesis of the full-length proteins and cause overall defect in protein synthesis. In conclusion, our data reveal the molecular roles of U2552 methylation in both ribosome biogenesis and protein translation.
Collapse
|
22
|
Kailasam S, Singh S, Liu MJ, Lin CC, Yeh KC. A HemK class glutamine-methyltransferase is involved in the termination of translation and essential for iron homeostasis in Arabidopsis. THE NEW PHYTOLOGIST 2020; 226:1361-1374. [PMID: 31968122 DOI: 10.1111/nph.16440] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 01/09/2020] [Indexed: 06/10/2023]
Abstract
Iron (Fe) transport and utilization are controlled by Fe-dependent transcriptional cascades. Many genes participate in these processes, transcriptionally controlled by Fe-status. Thorough knowledge of the translational check-points is lacking. We identified a non-response to Fe-deficiency1-1 (nrf1-1) mutant of Arabidopsis thaliana, which displayed a hypersensitive phenotype under Fe-deficient conditions. By mapping nrf1-1, we found that the AT3G13440 locus encoding a HemK methyltransferase is responsible for the phenotype. Analyses of ProUBQ10:NRF1CDS overexpression nrf1-1 lines and a T-DNA insertion mutant nrf1-2, confirmed that loss-of-function of NRF1 results in enhanced Fe-starvation-sensitivity. NRF1 is required for the proper expression of the majority of Fe-deficiency-inducible (FDI) genes. The nrf1 mutants accumulated more polysomes in the roots, due to stalled ribosomes on several transcripts. Ribosome-footprint (RF) mapping revealed that ribosomes are stalled at a stop codon that amplified the stalling of trailing ribosomes. We detected higher RF levels in many FDI transcripts in nrf1-2. Our study demonstrates the requirement of NRF1 for an accurate termination of protein synthesis essential not only for a precise iron homeostasis, but also cellular ion balance. NRF1 is also important for normal growth and development. A check-point that fine-tunes peptide release in plants is uncovered.
Collapse
Affiliation(s)
- Sakthivel Kailasam
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan
| | - Surjit Singh
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica and National Chung Hsing University, Taipei, 11529, Taiwan
- Graduate Institute of Biotechnology, National Chung Hsing University, Taichung, 40227, Taiwan
| | - Ming-Jung Liu
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan
| | - Chih-Ching Lin
- Institute of Plant and Microbial Biology, Academia Sinica, Taipei, 11529, Taiwan
| | - Kuo-Chen Yeh
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, 11529, Taiwan
- Molecular and Biological Agricultural Sciences Program, Taiwan International Graduate Program, Academia Sinica and National Chung Hsing University, Taipei, 11529, Taiwan
| |
Collapse
|
23
|
Emmanuel JS, Sengupta A, Gordon ER, Noble JT, Cruz-Vera LR. The regulatory TnaC nascent peptide preferentially inhibits release factor 2-mediated hydrolysis of peptidyl-tRNA. J Biol Chem 2019; 294:19224-19235. [PMID: 31712310 DOI: 10.1074/jbc.ra119.011313] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 11/01/2019] [Indexed: 01/29/2023] Open
Abstract
The tnaC regulatory gene from the tna operon of Escherichia coli controls the transcription of its own operon through an attenuation mechanism relying on the accumulation of arrested ribosomes during inhibition of its own translation termination. This free l-Trp-dependent mechanism of inhibition of translation termination remains unclear. Here, we analyzed the inhibitory effects of l-Trp on the function of two known E. coli translation termination factors, RF1 and RF2. Using a series of reporter genes, we found that the in vivo l-Trp sensitivity of tnaC gene expression is influenced by the identity of its stop codon, with the UGA stop codon producing higher expression efficiency of the tnaA-lacZ gene construct than the UAG stop codon. In vitro TnaC-peptidyl-tRNA accumulation and toe-printing assays confirmed that in the presence of l-Trp, the UGA stop codon generates higher accumulation of both TnaC-peptidyl-tRNA and arrested ribosomes than does the UAG stop codon. RF-mediated hydrolysis assays corroborated that l-Trp blocks RF2 function more than that of RF1. Mutational analyses disclosed that amino acids substitutions at the 246 and 256 residue positions surrounding the RF2-GGQ functional motif reduce l-Trp-dependent expression of the tnaC(UGA) tnaA-lacZ construct and the ability of l-Trp to inhibit RF2-mediated cleavage of the TnaC-peptidyl-tRNA. Altogether, our results indicate that l-Trp preferentially blocks RF2 activity during translation termination of the tnaC gene. This inhibition depends on the identities of amino acid residues surrounding the RF2-GGQ functional motif.
Collapse
Affiliation(s)
| | - Arnab Sengupta
- University of Alabama in Huntsville, Huntsville, Alabama 35899
| | | | | | | |
Collapse
|
24
|
Woodcock CB, Yu D, Zhang X, Cheng X. Human HemK2/KMT9/N6AMT1 is an active protein methyltransferase, but does not act on DNA in vitro, in the presence of Trm112. Cell Discov 2019; 5:50. [PMID: 31632689 PMCID: PMC6796829 DOI: 10.1038/s41421-019-0119-5] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 08/06/2019] [Indexed: 01/10/2023] Open
Affiliation(s)
- Clayton B. Woodcock
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA
| | - Dan Yu
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA
| | - Xing Zhang
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA
| | - Xiaodong Cheng
- Department of Epigenetics and Molecular Carcinogenesis, University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA
| |
Collapse
|
25
|
Structural insight into human N6amt1-Trm112 complex functioning as a protein methyltransferase. Cell Discov 2019; 5:51. [PMID: 31636962 PMCID: PMC6796863 DOI: 10.1038/s41421-019-0121-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 08/08/2019] [Indexed: 02/07/2023] Open
Abstract
DNA methylation is an important epigenetic modification in many organisms and can occur on cytosine or adenine. N6-methyladenine (6mA) exists widespreadly in bacterial genomes, which plays a vital role in the bacterial restriction-modification system. Recently, 6mA has also been reported to exist in the genomes of a variety of eukaryotes from unicellular organisms to metazoans. There were controversial reports on whether human N6amt1, which was originally reported as a glutamine MTase for eRF1, is a putative 6mA DNA MTase. We report here the crystal structure of human N6amt1–Trm112 in complex with cofactor SAM. Structural analysis shows that Trm112 binds to a hydrophobic surface of N6amt1 to stabilize its structure but does not directly contribute to substrate binding and catalysis. The active site and potential substrate-binding site of N6amt1 are dominantly negatively charged and thus are unsuitable for DNA binding. The biochemical data confirm that the complex cannot bind DNA and has no MTase activity for DNA, but exhibits activity for the methylation of Gln185 of eRF1. Our structural and biochemical data together demonstrate that N6amt1 is a bona fide protein MTase rather than a DNA MTase.
Collapse
|
26
|
The structural basis for release-factor activation during translation termination revealed by time-resolved cryogenic electron microscopy. Nat Commun 2019; 10:2579. [PMID: 31189921 PMCID: PMC6561943 DOI: 10.1038/s41467-019-10608-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 05/14/2019] [Indexed: 11/08/2022] Open
Abstract
When the ribosome encounters a stop codon, it recruits a release factor (RF) to hydrolyze the ester bond between the peptide chain and tRNA. RFs have structural motifs that recognize stop codons in the decoding center and a GGQ motif for induction of hydrolysis in the peptidyl transfer center 70 Å away. Surprisingly, free RF2 is compact, with only 20 Å between its codon-reading and GGQ motifs. Cryo-EM showed that ribosome-bound RFs have extended structures, suggesting that RFs are compact when entering the ribosome and then extend their structures upon stop codon recognition. Here we use time-resolved cryo-EM to visualize transient compact forms of RF1 and RF2 at 3.5 and 4 Å resolution, respectively, in the codon-recognizing ribosome complex on the native pathway. About 25% of complexes have RFs in the compact state at 24 ms reaction time, and within 60 ms virtually all ribosome-bound RFs are transformed to their extended forms. Translation termination is under strong selection pressure for high speed and accuracy. Here the authors provide a 3D view of the dynamics of a translating bacterial ribosome as it recruits a class-1 release factor (RF1 or RF2) upon encountering a stop codon, and propose a structure-based kinetic model for the early steps in bacterial translation termination.
Collapse
|
27
|
van Tran N, Muller L, Ross RL, Lestini R, Létoquart J, Ulryck N, Limbach PA, de Crécy-Lagard V, Cianférani S, Graille M. Evolutionary insights into Trm112-methyltransferase holoenzymes involved in translation between archaea and eukaryotes. Nucleic Acids Res 2018; 46:8483-8499. [PMID: 30010922 PMCID: PMC6144793 DOI: 10.1093/nar/gky638] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Revised: 06/25/2018] [Accepted: 07/04/2018] [Indexed: 12/22/2022] Open
Abstract
Protein synthesis is a complex and highly coordinated process requiring many different protein factors as well as various types of nucleic acids. All translation machinery components require multiple maturation events to be functional. These include post-transcriptional and post-translational modification steps and methylations are the most frequent among these events. In eukaryotes, Trm112, a small protein (COG2835) conserved in all three domains of life, interacts and activates four methyltransferases (Bud23, Trm9, Trm11 and Mtq2) that target different components of the translation machinery (rRNA, tRNAs, release factors). To clarify the function of Trm112 in archaea, we have characterized functionally and structurally its interaction network using Haloferax volcanii as model system. This led us to unravel that methyltransferases are also privileged Trm112 partners in archaea and that this Trm112 network is much more complex than anticipated from eukaryotic studies. Interestingly, among the identified enzymes, some are functionally orthologous to eukaryotic Trm112 partners, emphasizing again the similarity between eukaryotic and archaeal translation machineries. Other partners display some similarities with bacterial methyltransferases, suggesting that Trm112 is a general partner for methyltransferases in all living organisms.
Collapse
Affiliation(s)
- Nhan van Tran
- Laboratoire de Biochimie, Ecole polytechnique, CNRS, Université Paris-Saclay, F-91128 Palaiseau cedex, France
| | - Leslie Muller
- Laboratoire de Spectrométrie de Masse BioOrganique (LSMBO), Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Robert L Ross
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, OH 45221-0172, USA
| | - Roxane Lestini
- Laboratoire d’Optique et Biosciences, Ecole Polytechnique, CNRS UMR7645-INSERM U1182 91128, Palaiseau Cedex, France
| | - Juliette Létoquart
- Laboratoire de Biochimie, Ecole polytechnique, CNRS, Université Paris-Saclay, F-91128 Palaiseau cedex, France
| | - Nathalie Ulryck
- Laboratoire de Biochimie, Ecole polytechnique, CNRS, Université Paris-Saclay, F-91128 Palaiseau cedex, France
| | - Patrick A Limbach
- Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, OH 45221-0172, USA
| | - Valérie de Crécy-Lagard
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611, USA
| | - Sarah Cianférani
- Laboratoire de Spectrométrie de Masse BioOrganique (LSMBO), Université de Strasbourg, CNRS, IPHC UMR 7178, F-67000 Strasbourg, France
| | - Marc Graille
- Laboratoire de Biochimie, Ecole polytechnique, CNRS, Université Paris-Saclay, F-91128 Palaiseau cedex, France
| |
Collapse
|
28
|
Zeng F, Jin H. Conformation of methylated GGQ in the Peptidyl Transferase Center during Translation Termination. Sci Rep 2018; 8:2349. [PMID: 29403017 PMCID: PMC5799190 DOI: 10.1038/s41598-018-20107-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 01/12/2018] [Indexed: 11/24/2022] Open
Abstract
The universally conserved Gly-Gly-Gln (GGQ) tripeptide in release factors or release factor-like surveillance proteins is required to catalyze the release of nascent peptide in the ribosome. The glutamine of the GGQ is methylated post-translationally at the N5 position in vivo; this covalent modification is essential for optimal cell growth and efficient translation termination. However, the precise conformation of the methylated-GGQ tripeptide in the ribosome remains unknown. Using cryoEM and X-ray crystallography, we report the conformation of methylated-GGQ in the peptidyl transferase center of the ribosome during canonical translational termination and co-translation quality control. It has been suggested that the GGQ motif arose independently through convergent evolution among otherwise unrelated proteins that catalyze peptide release. The requirement for this tripeptide in the highly conserved peptidyl transferase center suggests that the conformation reported here is likely shared during termination of protein synthesis in all domains of life.
Collapse
Affiliation(s)
- Fuxing Zeng
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, USA
| | - Hong Jin
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, USA. .,Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, USA.
| |
Collapse
|
29
|
Zhang M, Xu JY, Hu H, Ye BC, Tan M. Systematic Proteomic Analysis of Protein Methylation in Prokaryotes and Eukaryotes Revealed Distinct Substrate Specificity. Proteomics 2017; 18. [PMID: 29150981 DOI: 10.1002/pmic.201700300] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 10/25/2017] [Indexed: 11/07/2022]
Abstract
The studies of protein methylation mainly focus on lysine and arginine residues due to their diverse roles in essential cellular processes from gene expression to signal transduction. Nevertheless, atypical protein methylation occurring on amino acid residues, such as glutamine and glutamic acid, is largely neglected until recently. In addition, the systematic analysis for the distribution of methylation on different amino acids in various species is still lacking, which hinders our understanding of its functional roles. In this study, we deeply explored the methylated sites in three species Escherichia coli, Saccharomyces cerevisiae, and HeLa cells by employing MS-based proteomic approach coupled with heavy methyl SILAC method. We identify a total of 234 methylated sites on 187 proteins with high localization confidence, including 94 unreported methylated sites on nine different amino acid residues. KEGG and gene ontology analysis show the pathways enriched with methylated proteins are mainly involved in central metabolism for E. coli and S. cerevisiae, but related to spliceosome for HeLa cells. The analysis of methylation preference on different amino acids is conducted in three species. Protein N-terminal methylation is dominant in E. coli while methylated lysines and arginines are widely identified in S. cerevisiae and HeLa cells, respectively. To study whether some atypical protein methylation has biological relevance in the pathological process in mammalian cells, we focus on histone methylation in diet-induced obese (DIO) mouse. Two glutamate methylation sites showed statistical significance in DIO mice compared with chow-fed mice, suggesting their potential roles in diabetes and obesity. Together, these findings expanded the methylome database from microbes to mammals, which will benefit our further appreciation for the protein methylation as well as its possible functions on disease.
Collapse
Affiliation(s)
- Min Zhang
- The Chemical Proteomics Center and State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Jun-Yu Xu
- The Chemical Proteomics Center and State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Hao Hu
- The Chemical Proteomics Center and State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Bang-Ce Ye
- Lab of Biosystems and Microanalysis, State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, China
| | - Minjia Tan
- The Chemical Proteomics Center and State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
30
|
Pierson WE, Hoffer ED, Keedy HE, Simms CL, Dunham CM, Zaher HS. Uniformity of Peptide Release Is Maintained by Methylation of Release Factors. Cell Rep 2017; 17:11-18. [PMID: 27681416 DOI: 10.1016/j.celrep.2016.08.085] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 06/30/2016] [Accepted: 08/24/2016] [Indexed: 10/20/2022] Open
Abstract
Termination of protein synthesis on the ribosome is catalyzed by release factors (RFs), which share a conserved glycine-glycine-glutamine (GGQ) motif. The glutamine residue is methylated in vivo, but a mechanistic understanding of its contribution to hydrolysis is lacking. Here, we show that the modification, apart from increasing the overall rate of termination on all dipeptides, substantially increases the rate of peptide release on a subset of amino acids. In the presence of unmethylated RFs, we measure rates of hydrolysis that are exceptionally slow on proline and glycine residues and approximately two orders of magnitude faster in the presence of the methylated factors. Structures of 70S ribosomes bound to methylated RF1 and RF2 reveal that the glutamine side-chain methylation packs against 23S rRNA nucleotide 2451, stabilizing the GGQ motif and placing the side-chain amide of the glutamine toward tRNA. These data provide a framework for understanding how release factor modifications impact termination.
Collapse
Affiliation(s)
- William E Pierson
- Department of Biology, Washington University in St. Louis, Campus Box 1137, 1 Brookings Drive, St. Louis, MO 63130, USA
| | - Eric D Hoffer
- Biochemistry, Cell and Developmental Biology Graduate Program, Emory University School of Medicine, 1510 Clifton Road NE, Room G223, Atlanta, GA 30322, USA; Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road NE, Room G223, Atlanta, GA 30322, USA
| | - Hannah E Keedy
- Department of Biology, Washington University in St. Louis, Campus Box 1137, 1 Brookings Drive, St. Louis, MO 63130, USA
| | - Carrie L Simms
- Department of Biology, Washington University in St. Louis, Campus Box 1137, 1 Brookings Drive, St. Louis, MO 63130, USA
| | - Christine M Dunham
- Department of Biochemistry, Emory University School of Medicine, 1510 Clifton Road NE, Room G223, Atlanta, GA 30322, USA.
| | - Hani S Zaher
- Department of Biology, Washington University in St. Louis, Campus Box 1137, 1 Brookings Drive, St. Louis, MO 63130, USA.
| |
Collapse
|
31
|
Korkmaz G, Sanyal S. R213I mutation in release factor 2 (RF2) is one step forward for engineering an omnipotent release factor in bacteria Escherichia coli. J Biol Chem 2017; 292:15134-15142. [PMID: 28743745 DOI: 10.1074/jbc.m117.785238] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Revised: 07/23/2017] [Indexed: 11/06/2022] Open
Abstract
The current understanding of the specificity of the bacterial class I release factors (RFs) in decoding stop codons has evolved beyond a simple tripeptide anticodon model. A recent molecular dynamics study for deciphering the principles for specific stop codon recognition by RFs identified Arg-213 as a crucial residue on Escherichia coli RF2 for discriminating guanine in the third position (G3). Interestingly, Arg-213 is highly conserved in RF2 and substituted by Ile-196 in the corresponding position in RF1. Another similar pair is Leu-126 in RF1 and Asp-143 in RF2, which are also conserved within their respective groups. With the hypothesis that replacement of Arg-213 and Asp-143 with the corresponding RF1 residues will reduce G3 discrimination by RF2, we swapped these residues between E. coli RF1 and RF2 by site-directed mutagenesis and characterized their preference for different codons using a competitive peptide release assay. Among these, the R213I mutant of RF2 showed 5-fold improved reading of the RF1-specific UAG codon relative to UAA, the universal stop codon, compared with the wild type (WT). In-depth fast kinetic studies revealed that the gain in UAG reading by RF2 R213I is associated with a reduced efficiency of termination on the cognate UAA codon. Our work highlights the notion that stop codon recognition involves complex interactions with multiple residues beyond the PXT/SPF motifs. We propose that the R213I mutation in RF2 brings us one step forward toward engineering an omnipotent RF in bacteria, capable of reading all three stop codons.
Collapse
Affiliation(s)
- Gürkan Korkmaz
- From the Department of Cell and Molecular Biology, Uppsala University, Box-596, 75124 Uppsala, Sweden
| | - Suparna Sanyal
- From the Department of Cell and Molecular Biology, Uppsala University, Box-596, 75124 Uppsala, Sweden
| |
Collapse
|
32
|
Novel genes associated with enhanced motility of Escherichia coli ST131. PLoS One 2017; 12:e0176290. [PMID: 28489862 PMCID: PMC5425062 DOI: 10.1371/journal.pone.0176290] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2016] [Accepted: 04/07/2017] [Indexed: 12/20/2022] Open
Abstract
Uropathogenic Escherichia coli (UPEC) is the cause of ~75% of all urinary tract infections (UTIs) and is increasingly associated with multidrug resistance. This includes UPEC strains from the recently emerged and globally disseminated sequence type 131 (ST131), which is now the dominant fluoroquinolone-resistant UPEC clone worldwide. Most ST131 strains are motile and produce H4-type flagella. Here, we applied a combination of saturated Tn5 mutagenesis and transposon directed insertion site sequencing (TraDIS) as a high throughput genetic screen and identified 30 genes associated with enhanced motility of the reference ST131 strain EC958. This included 12 genes that repress motility of E. coli K-12, four of which (lrhA, ihfA, ydiV, lrp) were confirmed in EC958. Other genes represented novel factors that impact motility, and we focused our investigation on characterisation of the mprA, hemK and yjeA genes. Mutation of each of these genes in EC958 led to increased transcription of flagellar genes (flhD and fliC), increased expression of the FliC flagellin, enhanced flagella synthesis and a hyper-motile phenotype. Complementation restored all of these properties to wild-type level. We also identified Tn5 insertions in several intergenic regions (IGRs) on the EC958 chromosome that were associated with enhanced motility; this included flhDC and EC958_1546. In both of these cases, the Tn5 insertions were associated with increased transcription of the downstream gene(s), which resulted in enhanced motility. The EC958_1546 gene encodes a phage protein with similarity to esterase/deacetylase enzymes involved in the hydrolysis of sialic acid derivatives found in human mucus. We showed that over-expression of EC958_1546 led to enhanced motility of EC958 as well as the UPEC strains CFT073 and UTI89, demonstrating its activity affects the motility of different UPEC strains. Overall, this study has identified and characterised a number of novel factors associated with enhanced UPEC motility.
Collapse
|
33
|
Bourgeois G, Létoquart J, van Tran N, Graille M. Trm112, a Protein Activator of Methyltransferases Modifying Actors of the Eukaryotic Translational Apparatus. Biomolecules 2017; 7:biom7010007. [PMID: 28134793 PMCID: PMC5372719 DOI: 10.3390/biom7010007] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 01/16/2017] [Accepted: 01/18/2017] [Indexed: 12/17/2022] Open
Abstract
Post-transcriptional and post-translational modifications are very important for the control and optimal efficiency of messenger RNA (mRNA) translation. Among these, methylation is the most widespread modification, as it is found in all domains of life. These methyl groups can be grafted either on nucleic acids (transfer RNA (tRNA), ribosomal RNA (rRNA), mRNA, etc.) or on protein translation factors. This review focuses on Trm112, a small protein interacting with and activating at least four different eukaryotic methyltransferase (MTase) enzymes modifying factors involved in translation. The Trm112-Trm9 and Trm112-Trm11 complexes modify tRNAs, while the Trm112-Mtq2 complex targets translation termination factor eRF1, which is a tRNA mimic. The last complex formed between Trm112 and Bud23 proteins modifies 18S rRNA and participates in the 40S biogenesis pathway. In this review, we present the functions of these eukaryotic Trm112-MTase complexes, the molecular bases responsible for complex formation and substrate recognition, as well as their implications in human diseases. Moreover, as Trm112 orthologs are found in bacterial and archaeal genomes, the conservation of this Trm112 network beyond eukaryotic organisms is also discussed.
Collapse
Affiliation(s)
- Gabrielle Bourgeois
- Laboratoire de Biochimie, Ecole polytechnique, CNRS, Université Paris-Saclay, 91128 Palaiseau CEDEX, France.
| | - Juliette Létoquart
- Laboratoire de Biochimie, Ecole polytechnique, CNRS, Université Paris-Saclay, 91128 Palaiseau CEDEX, France.
- De Duve Institute, Université Catholique de Louvain, avenue Hippocrate 75, 1200 Brussels, Belgium.
| | - Nhan van Tran
- Laboratoire de Biochimie, Ecole polytechnique, CNRS, Université Paris-Saclay, 91128 Palaiseau CEDEX, France.
| | - Marc Graille
- Laboratoire de Biochimie, Ecole polytechnique, CNRS, Université Paris-Saclay, 91128 Palaiseau CEDEX, France.
| |
Collapse
|
34
|
Krueger J, Pohl S, Preusse M, Kordes A, Rugen N, Schniederjans M, Pich A, Häussler S. Unravelling post-transcriptional PrmC-dependent regulatory mechanisms in Pseudomonas aeruginosa. Environ Microbiol 2016; 18:3583-3592. [PMID: 27376486 DOI: 10.1111/1462-2920.13435] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 06/28/2016] [Indexed: 02/04/2023]
Abstract
Transcriptional regulation has a central role in cellular adaptation processes and is well investigated. In contrast, the importance of the post-transcriptional regulation on these processes is less well defined. The technological advancements have been critical to precisely quantify protein and mRNA level changes and hold promise to provide more insights into how post-transcriptional regulation determines phenotypes. In Pseudomonas aeruginosa the methyltransferase PrmC methylates peptide chain release factors to facilitate translation termination. Loss of PrmC activity abolishes anaerobic growth and leads to reduced production of quorum sensing-associated virulence factors. Here, by applying SILAC technology in combination with mRNA-sequencing, they provide evidence that the P. aeruginosa phenotype can be attributed to a change in protein to mRNA ratios of selected protein groups. The UAG-dependent translation termination was more dependent on PrmC activity than the UAA- and UGA-dependent translation termination. Additionally, a bias toward UAG stop codons in global transcriptional regulators was found. The finding that this bias in stop codon usage determines the P. aeruginosa phenotype is unexpected and adds complexity to regulatory circuits. Via modulation of PrmC activity the bacterial cell can cross-regulate targets independently of transcriptional signals, a process with an underestimated impact on the bacterial phenotype.
Collapse
Affiliation(s)
- Jonas Krueger
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany.,Research Core Unit Proteomics and Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Sarah Pohl
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany.,Department of Molecular Bacteriology, Helmholtz for Centre Infection Research, Braunschweig, Germany
| | - Matthias Preusse
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany.,Department of Molecular Bacteriology, Helmholtz for Centre Infection Research, Braunschweig, Germany
| | - Adrian Kordes
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany
| | - Nils Rugen
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany
| | - Monika Schniederjans
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany.,Department of Molecular Bacteriology, Helmholtz for Centre Infection Research, Braunschweig, Germany
| | - Andreas Pich
- Research Core Unit Proteomics and Institute of Toxicology, Hannover Medical School, Hannover, Germany
| | - Susanne Häussler
- Institute for Molecular Bacteriology, TWINCORE GmbH, Centre for Experimental and Clinical Infection Research, a joint venture of the Hannover Medical School and the Helmholtz Centre for Infection Research, Feodor-Lynen-Str. 7, 30625, Hannover, Germany. .,Department of Molecular Bacteriology, Helmholtz for Centre Infection Research, Braunschweig, Germany.
| |
Collapse
|
35
|
Kusevic D, Kudithipudi S, Jeltsch A. Substrate Specificity of the HEMK2 Protein Glutamine Methyltransferase and Identification of Novel Substrates. J Biol Chem 2016; 291:6124-33. [PMID: 26797129 DOI: 10.1074/jbc.m115.711952] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Indexed: 11/06/2022] Open
Abstract
Bacterial HEMK2 homologs initially had been proposed to be involved in heme biogenesis or to function as adenine DNA methyltransferase. Later it was shown that this family of enzymes has protein glutamine methyltransferase activity, and they methylate the glutamine residue in the GGQ motif of ribosomal translation termination factors. The murine HEMK2 enzyme methylates Gln(185) of the eukaryotic translation termination factor eRF1. We have employed peptide array libraries to investigate the peptide sequence recognition specificity of murine HEMK2. Our data show that HEMK2 requires a GQX3R motif for methylation activity. In addition, amino acid preferences were observed between the -3 and +7 positions of the peptide substrate (considering the target glutamine as 0), including a preference for Ser, Arg, and Gly at the +1 and a preference for Arg at the +7 position. Based on our specificity profile, we identified several human proteins that contain putative HEMK2 methylation sites and show that HEMK2 methylates 58 novel peptide substrates. After cloning, expression, and purification of the corresponding protein domains, we confirmed methylation for 11 of them at the protein level. Transfected CHD5 (chromodomain helicase DNA-binding protein 5) and NUT (nuclear protein in testis) were also demonstrated to be methylated by HEMK2 in human HEK293 cells. Our data expand the range of proteins potentially subjected to glutamine methylation significantly, but further investigation will be required to understand the function of HEMK2-mediated methylation in proteins other than eRF1.
Collapse
Affiliation(s)
- Denis Kusevic
- From the Institute of Biochemistry, Faculty of Chemistry, University Stuttgart, 70569 Stuttgart, Germany
| | - Srikanth Kudithipudi
- From the Institute of Biochemistry, Faculty of Chemistry, University Stuttgart, 70569 Stuttgart, Germany
| | - Albert Jeltsch
- From the Institute of Biochemistry, Faculty of Chemistry, University Stuttgart, 70569 Stuttgart, Germany
| |
Collapse
|
36
|
Iyer LM, Zhang D, Aravind L. Adenine methylation in eukaryotes: Apprehending the complex evolutionary history and functional potential of an epigenetic modification. Bioessays 2015; 38:27-40. [PMID: 26660621 PMCID: PMC4738411 DOI: 10.1002/bies.201500104] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
While N6‐methyladenosine (m6A) is a well‐known epigenetic modification in bacterial DNA, it remained largely unstudied in eukaryotes. Recent studies have brought to fore its potential epigenetic role across diverse eukaryotes with biological consequences, which are distinct and possibly even opposite to the well‐studied 5‐methylcytosine mark. Adenine methyltransferases appear to have been independently acquired by eukaryotes on at least 13 occasions from prokaryotic restriction‐modification and counter‐restriction systems. On at least four to five instances, these methyltransferases were recruited as RNA methylases. Thus, m6A marks in eukaryotic DNA and RNA might be more widespread and diversified than previously believed. Several m6A‐binding protein domains from prokaryotes were also acquired by eukaryotes, facilitating prediction of potential readers for these marks. Further, multiple lineages of the AlkB family of dioxygenases have been recruited as m6A demethylases. Although members of the TET/JBP family of dioxygenases have also been suggested to be m6A demethylases, this proposal needs more careful evaluation. Also watch the Video Abstract.
Collapse
Affiliation(s)
- Lakshminarayan M Iyer
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
| | - Dapeng Zhang
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
| | - L Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD, USA
| |
Collapse
|
37
|
Abstract
tRNA modifications are crucial for efficient and accurate protein translation, with defects often linked to disease. There are 7 cytoplasmic tRNA modifications in the yeast Saccharomyces cerevisiae that are formed by an enzyme consisting of a catalytic subunit and an auxiliary protein, 5 of which require only a single subunit in bacteria, and 2 of which are not found in bacteria. These enzymes include the deaminase Tad2-Tad3, and the methyltransferases Trm6-Trm61, Trm8-Trm82, Trm7-Trm732, and Trm7-Trm734, Trm9-Trm112, and Trm11-Trm112. We describe the occurrence and biological role of each modification, evidence for a required partner protein in S. cerevisiae and other eukaryotes, evidence for a single subunit in bacteria, and evidence for the role of the non-catalytic binding partner. Although it is unclear why these eukaryotic enzymes require partner proteins, studies of some 2-subunit modification enzymes suggest that the partner proteins help expand substrate range or allow integration of cellular activities.
Collapse
Affiliation(s)
- Michael P Guy
- a Department of Biochemistry and Biophysics; Center for RNA Biology ; University of Rochester School of Medicine ; Rochester , NY USA
| | | |
Collapse
|
38
|
Abstract
This review focuses on the steps unique to methionine biosynthesis, namely the conversion of homoserine to methionine. The past decade has provided a wealth of information concerning the details of methionine metabolism and the review focuses on providing a comprehensive overview of the field, emphasizing more recent findings. Details of methionine biosynthesis are addressed along with key cellular aspects, including regulation, uptake, utilization, AdoMet, the methyl cycle, and growing evidence that inhibition of methionine biosynthesis occurs under stressful cellular conditions. The first unique step in methionine biosynthesis is catalyzed by the metA gene product, homoserine transsuccinylase (HTS, or homoserine O-succinyltransferase). Recent experiments suggest that transcription of these genes is indeed regulated by MetJ, although the repressor-binding sites have not yet been verified. Methionine also serves as the precursor of S-adenosylmethionine, which is an essential molecule employed in numerous biological processes. S-adenosylhomocysteine is produced as a consequence of the numerous AdoMet-dependent methyl transfer reactions that occur within the cell. In E. coli and Salmonella, this molecule is recycled in two discrete steps to complete the methyl cycle. Cultures challenged by oxidative stress appear to experience a growth limitation that depends on methionine levels. E. coli that are deficient for the manganese and iron superoxide dismutases (the sodA and sodB gene products, respectively) require the addition of methionine or cysteine for aerobic growth. Modulation of methionine levels in response to stressful conditions further increases the complexity of its regulation.
Collapse
|
39
|
Indrisiunaite G, Pavlov MY, Heurgué-Hamard V, Ehrenberg M. On the pH dependence of class-1 RF-dependent termination of mRNA translation. J Mol Biol 2015; 427:1848-60. [PMID: 25619162 DOI: 10.1016/j.jmb.2015.01.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 01/05/2015] [Accepted: 01/09/2015] [Indexed: 10/24/2022]
Abstract
We have studied the pH dependence of the rate of termination of bacterial protein synthesis catalyzed by a class-1 release factor (RF1 or RF2). We used a classical quench-flow technique and a newly developed stopped-flow technique that relies on the use of fluorescently labeled peptides. We found the termination rate to increase with increasing pH and, eventually, to saturate at about 70 s(-1) with an apparent pKa value of about 7.6. From our data, we suggest that class-1 RF termination is rate limited by the chemistry of ester bond hydrolysis at low pH and by a stop-codon-dependent and pH-independent conformational change of RFs at high pH. We propose that RF-dependent termination depends on the participation of a hydroxide ion rather than a water molecule in the hydrolysis of the ester bond between the P-site tRNA and its peptide chain. We provide a simple explanation for why the rate of termination saturated at high pH in our experiments but not in those of others.
Collapse
Affiliation(s)
- Gabriele Indrisiunaite
- Department of Cell and Molecular Biology, Uppsala University, Biomedicinskt Centrum, Box 596, 75124 Uppsala, Sweden
| | - Michael Y Pavlov
- Department of Cell and Molecular Biology, Uppsala University, Biomedicinskt Centrum, Box 596, 75124 Uppsala, Sweden
| | - Valérie Heurgué-Hamard
- Centre National de la Recherche Scientifique, FRE3630, University Paris Diderot Sorbonne Paris Cité Institut de Biologie Physico-Chimique, 13 Rue Pierre et Marie Curie, 75005 Paris, France
| | - Måns Ehrenberg
- Department of Cell and Molecular Biology, Uppsala University, Biomedicinskt Centrum, Box 596, 75124 Uppsala, Sweden.
| |
Collapse
|
40
|
NAD captureSeq indicates NAD as a bacterial cap for a subset of regulatory RNAs. Nature 2014; 519:374-7. [PMID: 25533955 DOI: 10.1038/nature14020] [Citation(s) in RCA: 188] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 10/27/2014] [Indexed: 11/08/2022]
Abstract
A distinctive feature of prokaryotic gene expression is the absence of 5'-capped RNA. In eukaryotes, 5',5'-triphosphate-linked 7-methylguanosine protects messenger RNA from degradation and modulates maturation, localization and translation. Recently, the cofactor nicotinamide adenine dinucleotide (NAD) was reported as a covalent modification of bacterial RNA. Given the central role of NAD in redox biochemistry, posttranslational protein modification and signalling, its attachment to RNA indicates that there are unknown functions of RNA in these processes and undiscovered pathways in RNA metabolism and regulation. The unknown identity of NAD-modified RNAs has so far precluded functional analyses. Here we identify NAD-linked RNAs from bacteria by chemo-enzymatic capture and next-generation sequencing (NAD captureSeq). Among those identified, specific regulatory small RNAs (sRNAs) and sRNA-like 5'-terminal fragments of certain mRNAs are particularly abundant. Analogous to a eukaryotic cap, 5'-NAD modification is shown in vitro to stabilize RNA against 5'-processing by the RNA-pyrophosphohydrolase RppH and against endonucleolytic cleavage by ribonuclease (RNase) E. The nudix phosphohydrolase NudC decaps NAD-RNA and thereby triggers RNase-E-mediated RNA decay, while being inactive against triphosphate-RNA. In vivo, ∼13% of the abundant sRNA RNAI is NAD-capped in the presence, and ∼26% in the absence, of functional NudC. To our knowledge, this is the first description of a cap-like structure and a decapping machinery in bacteria.
Collapse
|
41
|
Gauntlett JC, Nilsson HO, Fulurija A, Marshall BJ, Benghezal M. Phase-variable restriction/modification systems are required for Helicobacter pylori colonization. Gut Pathog 2014; 6:35. [PMID: 25349630 PMCID: PMC4209511 DOI: 10.1186/s13099-014-0035-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 08/16/2014] [Indexed: 01/22/2023] Open
Abstract
Background One mechanism utilized by bacterial pathogens for host adaptation and immune evasion is the generation of phenotypic diversity by the phasevarion that results from the differential expression of a suite of genes regulated by the activity of a phase-variable methyltransferase within a restriction modification (RM) system. Phasevarions are active in Helicobacter pylori, however there have been no studies investigating the significance of phase-variable RM systems on host colonization. Methods Two mutant types incapable of phase variation were constructed; a clean deletion mutant (‘DEL’) and a mutant (‘ON’) where the homopolymeric repeat was replaced with a non-repeat synonymous sequence, resulting in expression of the full-length protein. The resulting mutants were assessed for their colonisation ability in the mouse model. Results Five phase-variable genes encoding either methyltransferases or members of RM systems were found in H. pylori OND79. Our mutants fell into three categories; 1, those with little effect on colonization, 2, those where expression of the full-length protein was detrimental, 3, those where both mutations were detrimental. Conclusions Our results demonstrated that phase-variable methyltransferases are critical to H. pylori colonization, suggesting that genome methylation and generation of epigenetic diversity is important for colonization and pathogenesis. The third category of mutants suggests that differential genome methylation status of H. pylori cell populations, achieved by the phasevarion, is essential for host adaptation. Studies of phase-variable RM mutants falling in the two other categories, not strictly required for colonization, represent a future perspective to investigate the role of phasevarion in persistence of H. pylori.
Collapse
Affiliation(s)
- Jonathan C Gauntlett
- Ondek Pty Ltd and Helicobacter pylori Research Laboratory, School of Pathology and Laboratory Medicine, Marshall Centre for Infectious Disease Research and Training, University of Western Australia, Nedlands 6009, Western Australia, Australia
| | - Hans-Olof Nilsson
- Ondek Pty Ltd and Helicobacter pylori Research Laboratory, School of Pathology and Laboratory Medicine, Marshall Centre for Infectious Disease Research and Training, University of Western Australia, Nedlands 6009, Western Australia, Australia
| | - Alma Fulurija
- Ondek Pty Ltd and Helicobacter pylori Research Laboratory, School of Pathology and Laboratory Medicine, Marshall Centre for Infectious Disease Research and Training, University of Western Australia, Nedlands 6009, Western Australia, Australia
| | - Barry J Marshall
- Ondek Pty Ltd and Helicobacter pylori Research Laboratory, School of Pathology and Laboratory Medicine, Marshall Centre for Infectious Disease Research and Training, University of Western Australia, Nedlands 6009, Western Australia, Australia
| | - Mohammed Benghezal
- Ondek Pty Ltd and Helicobacter pylori Research Laboratory, School of Pathology and Laboratory Medicine, Marshall Centre for Infectious Disease Research and Training, University of Western Australia, Nedlands 6009, Western Australia, Australia
| |
Collapse
|
42
|
Histidine methylation of yeast ribosomal protein Rpl3p is required for proper 60S subunit assembly. Mol Cell Biol 2014; 34:2903-16. [PMID: 24865971 DOI: 10.1128/mcb.01634-13] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Histidine protein methylation is an unusual posttranslational modification. In the yeast Saccharomyces cerevisiae, the large ribosomal subunit protein Rpl3p is methylated at histidine 243, a residue that contacts the 25S rRNA near the P site. Rpl3p methylation is dependent upon the presence of Hpm1p, a candidate seven-beta-strand methyltransferase. In this study, we elucidated the biological activities of Hpm1p in vitro and in vivo. Amino acid analyses reveal that Hpm1p is responsible for all of the detectable protein histidine methylation in yeast. The modification is found on a polypeptide corresponding to the size of Rpl3p in ribosomes and in a nucleus-containing organelle fraction but was not detected in proteins of the ribosome-free cytosol fraction. In vitro assays demonstrate that Hpm1p has methyltransferase activity on ribosome-associated but not free Rpl3p, suggesting that its activity depends on interactions with ribosomal components. hpm1 null cells are defective in early rRNA processing, resulting in a deficiency of 60S subunits and translation initiation defects that are exacerbated in minimal medium. Cells lacking Hpm1p are resistant to cycloheximide and verrucarin A and have decreased translational fidelity. We propose that Hpm1p plays a role in the orchestration of the early assembly of the large ribosomal subunit and in faithful protein production.
Collapse
|
43
|
Grosjean H, Breton M, Sirand-Pugnet P, Tardy F, Thiaucourt F, Citti C, Barré A, Yoshizawa S, Fourmy D, de Crécy-Lagard V, Blanchard A. Predicting the minimal translation apparatus: lessons from the reductive evolution of mollicutes. PLoS Genet 2014; 10:e1004363. [PMID: 24809820 PMCID: PMC4014445 DOI: 10.1371/journal.pgen.1004363] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 03/24/2014] [Indexed: 11/18/2022] Open
Abstract
Mollicutes is a class of parasitic bacteria that have evolved from a common Firmicutes ancestor mostly by massive genome reduction. With genomes under 1 Mbp in size, most Mollicutes species retain the capacity to replicate and grow autonomously. The major goal of this work was to identify the minimal set of proteins that can sustain ribosome biogenesis and translation of the genetic code in these bacteria. Using the experimentally validated genes from the model bacteria Escherichia coli and Bacillus subtilis as input, genes encoding proteins of the core translation machinery were predicted in 39 distinct Mollicutes species, 33 of which are culturable. The set of 260 input genes encodes proteins involved in ribosome biogenesis, tRNA maturation and aminoacylation, as well as proteins cofactors required for mRNA translation and RNA decay. A core set of 104 of these proteins is found in all species analyzed. Genes encoding proteins involved in post-translational modifications of ribosomal proteins and translation cofactors, post-transcriptional modifications of t+rRNA, in ribosome assembly and RNA degradation are the most frequently lost. As expected, genes coding for aminoacyl-tRNA synthetases, ribosomal proteins and initiation, elongation and termination factors are the most persistent (i.e. conserved in a majority of genomes). Enzymes introducing nucleotides modifications in the anticodon loop of tRNA, in helix 44 of 16S rRNA and in helices 69 and 80 of 23S rRNA, all essential for decoding and facilitating peptidyl transfer, are maintained in all species. Reconstruction of genome evolution in Mollicutes revealed that, beside many gene losses, occasional gains by horizontal gene transfer also occurred. This analysis not only showed that slightly different solutions for preserving a functional, albeit minimal, protein synthetizing machinery have emerged in these successive rounds of reductive evolution but also has broad implications in guiding the reconstruction of a minimal cell by synthetic biology approaches.
Collapse
Affiliation(s)
- Henri Grosjean
- Centre de Génétique Moléculaire, UPR 3404, CNRS, Université Paris-Sud, FRC 3115, Gif-sur-Yvette, France
| | - Marc Breton
- INRA, UMR 1332 de Biologie du Fruit et Pathologie, Villenave d'Ornon, France
- Univ. Bordeaux, UMR 1332 de Biologie du Fruit et Pathologie, Villenave d'Ornon, France
| | - Pascal Sirand-Pugnet
- INRA, UMR 1332 de Biologie du Fruit et Pathologie, Villenave d'Ornon, France
- Univ. Bordeaux, UMR 1332 de Biologie du Fruit et Pathologie, Villenave d'Ornon, France
| | - Florence Tardy
- Anses, Laboratoire de Lyon, UMR Mycoplasmoses des Ruminants, Lyon, France
- Université de Lyon, VetAgro Sup, UMR Mycoplasmoses des Ruminants, Marcy L'Etoile, France
| | - François Thiaucourt
- Centre International de Recherche en Agronomie pour le Développement, UMR CMAEE, Montpellier, France
| | - Christine Citti
- INRA, UMR1225, Ecole Nationale Vétérinaire de Toulouse, Toulouse, France
- Université de Toulouse, INP-ENVT, UMR1225, Ecole Nationale Vétérinaire de Toulouse, Toulouse, France
| | - Aurélien Barré
- Univ. Bordeaux, Centre de bioinformatique et de génomique fonctionnelle, CBiB, Bordeaux, France
| | - Satoko Yoshizawa
- Centre de Génétique Moléculaire, UPR 3404, CNRS, Université Paris-Sud, FRC 3115, Gif-sur-Yvette, France
| | - Dominique Fourmy
- Centre de Génétique Moléculaire, UPR 3404, CNRS, Université Paris-Sud, FRC 3115, Gif-sur-Yvette, France
| | - Valérie de Crécy-Lagard
- Department of Microbiology and Cell Science, University Florida, Gainesville, Florida, United States of America
| | - Alain Blanchard
- INRA, UMR 1332 de Biologie du Fruit et Pathologie, Villenave d'Ornon, France
- Univ. Bordeaux, UMR 1332 de Biologie du Fruit et Pathologie, Villenave d'Ornon, France
- * E-mail:
| |
Collapse
|
44
|
A SAM-dependent methyltransferase cotranscribed with arsenate reductase alters resistance to peptidyl transferase center-binding antibiotics in Azospirillum brasilense Sp7. Appl Microbiol Biotechnol 2014; 98:4625-36. [PMID: 24573606 DOI: 10.1007/s00253-014-5574-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 01/23/2014] [Accepted: 01/25/2014] [Indexed: 10/25/2022]
Abstract
The genome of Azospirillum brasilense harbors a gene encoding S-adenosylmethionine-dependent methyltransferase, which is located downstream of an arsenate reductase gene. Both genes are cotranscribed and translationally coupled. When they were cloned and expressed individually in an arsenate-sensitive strain of Escherichia coli, arsenate reductase conferred tolerance to arsenate; however, methyltransferase failed to do so. Sequence analysis revealed that methyltransferase was more closely related to a PrmB-type N5-glutamine methyltransferase than to the arsenate detoxifying methyltransferase ArsM. Insertional inactivation of prmB gene in A. brasilense resulted in an increased sensitivity to chloramphenicol and resistance to tiamulin and clindamycin, which are known to bind at the peptidyl transferase center (PTC) in the ribosome. These observations suggested that the inability of prmB:km mutant to methylate L3 protein might alter hydrophobicity in the antibiotic-binding pocket of the PTC, which might affect the binding of chloramphenicol, clindamycin, and tiamulin differentially. This is the first report showing the role of PrmB-type N5-glutamine methyltransferases in conferring resistance to tiamulin and clindamycin in any bacterium.
Collapse
|
45
|
Abstract
The genomic revolution promises great advances in the search for useful biocatalysts. Function-based metagenomic approaches have identified several enzymes with properties that make them useful candidates for a variety of bioprocesses. As DNA sequencing costs continue to decline, the volume of genomic data, along with their corresponding predicted protein sequences, will continue to increase dramatically, necessitating new approaches to leverage this information for gene-based bioprospecting efforts. Additionally, as new functions are discovered and correlated with this sequence information, the knowledge of the often complex relationship between a protein's sequence and function will improve. This in turn will lead to better gene-based bioprospecting approaches and facilitate the tailoring of desired properties through protein engineering projects. In this chapter, we discuss a number of recent advances in bioprospecting within the context of the genomic age.
Collapse
Affiliation(s)
- Michael A Hicks
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Kristala L J Prather
- Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA; Synthetic Biology Engineering Research Center (SynBERC), Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
| |
Collapse
|
46
|
Santos N, Zhu J, Donohue JP, Korostelev AA, Noller HF. Crystal structure of the 70S ribosome bound with the Q253P mutant form of release factor RF2. Structure 2013; 21:1258-63. [PMID: 23769667 DOI: 10.1016/j.str.2013.04.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Revised: 03/26/2013] [Accepted: 04/26/2013] [Indexed: 11/25/2022]
Abstract
Bacterial translation termination is mediated by release factors RF1 and RF2, which recognize stop codons and catalyze hydrolysis of the peptidyl-tRNA ester bond. The catalytic mechanism has been debated. We proposed that the backbone amide NH group, rather than the side chain, of the glutamine of the universally conserved GGQ motif participates in catalysis by H-bonding to the tetrahedral transition-state intermediate and by product stabilization. This was supported by complete loss of RF1 catalytic activity when glutamine is replaced by proline, the only residue that lacks a backbone NH group. Here, we present the 3.4 Å crystal structure of the ribosome complex containing the RF2 Q253P mutant and find that its fold, including the GGP sequence, is virtually identical to that of wild-type RF2. This rules out proline-induced misfolding and further supports the proposal that catalytic activity requires interaction of the Gln-253 backbone amide with the 3' end of peptidyl-tRNA.
Collapse
Affiliation(s)
- Natalia Santos
- Center for Molecular Biology of RNA and Department of Molecular, Cell and Developmental Biology, University of California at Santa Cruz, Santa Cruz, CA 95064, USA
| | | | | | | | | |
Collapse
|
47
|
Pustelny C, Brouwer S, Müsken M, Bielecka A, Dötsch A, Nimtz M, Häussler S. The peptide chain release factor methyltransferase PrmC is essential for pathogenicity and environmental adaptation of Pseudomonas aeruginosa PA14. Environ Microbiol 2012; 15:597-609. [PMID: 23278968 DOI: 10.1111/1462-2920.12040] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2012] [Accepted: 11/02/2012] [Indexed: 01/30/2023]
Abstract
Pseudomonas aeruginosa pathogenicity and its capability to adapt to multiple environments are dependent on the production of diverse virulence factors, controlled by the sophisticated quorum sensing (QS) network of P. aeruginosa. To better understand the molecular mechanisms that underlie this adaptation we searched for novel key regulators of virulence factor production by screening a PA14 transposon mutant library for potential candidates acting downstream of the unique 2-alkyl-4-quinolone (AQ) QS system of P. aeruginosa. We focused the work on a protein named HemK with high homology to PrmC of Escherichia coli displaying a similar enzymatic activity (therefore also referred to as PrmC). In this study, we demonstrate that PrmC is an S-adenosyl-l-methionine (AdoMet)-dependent methyltransferase of peptide chain release factors (RFs) essential for the expression of several virulence factors, such as pyocyanin, rhamnolipids and the type III-secreted toxin ExoT. Furthermore, the PA14_prmC mutant strain is unable to grow under anoxic conditions and has a significantly reduced pathogenicity in the infection model Galleria mellonella. Along with transcriptomic and proteomic analyses, the presented data indicate that the methylation of RFs in P. aeruginosa seems to have a global effect on cellular processes related to the virulence of this nosocomial pathogen.
Collapse
Affiliation(s)
- Christian Pustelny
- Department of Molecular Bacteriology, Helmholtz Center for Infection Research, Braunschweig, Germany.
| | | | | | | | | | | | | |
Collapse
|
48
|
Graille M, Figaro S, Kervestin S, Buckingham RH, Liger D, Heurgué-Hamard V. Methylation of class I translation termination factors: structural and functional aspects. Biochimie 2012; 94:1533-43. [PMID: 22266024 DOI: 10.1016/j.biochi.2012.01.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 01/07/2012] [Indexed: 12/23/2022]
Abstract
During protein synthesis, release of polypeptide from the ribosome occurs when an in frame termination codon is encountered. Contrary to sense codons, which are decoded by tRNAs, stop codons present in the A-site are recognized by proteins named class I release factors, leading to the release of newly synthesized proteins. Structures of these factors bound to termination ribosomal complexes have recently been obtained, and lead to a better understanding of stop codon recognition and its coordination with peptidyl-tRNA hydrolysis in bacteria. Release factors contain a universally conserved GGQ motif which interacts with the peptidyl-transferase centre to allow peptide release. The Gln side chain from this motif is methylated, a feature conserved from bacteria to man, suggesting an important biological role. However, methylation is catalysed by completely unrelated enzymes. The function of this motif and its post-translational modification will be discussed in the context of recent structural and functional studies.
Collapse
Affiliation(s)
- Marc Graille
- IBBMC, Université Paris-Sud 11, CNRS UMR8619, Orsay Cedex, F-91405, France.
| | | | | | | | | | | |
Collapse
|
49
|
Eshghi A, Pinne M, Haake DA, Zuerner RL, Frank A, Cameron CE. Methylation and in vivo expression of the surface-exposed Leptospira interrogans outer-membrane protein OmpL32. MICROBIOLOGY-SGM 2011; 158:622-635. [PMID: 22174381 DOI: 10.1099/mic.0.054767-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Recent studies have revealed that bacterial protein methylation is a widespread post-translational modification that is required for virulence in selected pathogenic bacteria. In particular, altered methylation of outer-membrane proteins has been shown to modulate the effectiveness of the host immune response. In this study, 2D gel electrophoresis combined with MALDI-TOF MS identified a Leptospira interrogans serovar Copenhageni strain Fiocruz L1-130 protein, corresponding to ORF LIC11848, which undergoes extensive and differential methylation of glutamic acid residues. Immunofluorescence microscopy implicated LIC11848 as a surface-exposed outer-membrane protein, prompting the designation OmpL32. Indirect immunofluorescence microscopy of golden Syrian hamster liver and kidney sections revealed expression of OmpL32 during colonization of these organs. Identification of methylated surface-exposed outer-membrane proteins, such as OmpL32, provides a foundation for delineating the role of this post-translational modification in leptospiral virulence.
Collapse
Affiliation(s)
- Azad Eshghi
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| | - Marija Pinne
- Department of Medicine, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA.,Research Service, 151, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - David A Haake
- Division of Infectious Diseases, 111F, Veterans Affairs Greater Los Angeles Healthcare System, Los Angeles, CA, USA.,Department of Medicine, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, CA, USA
| | - Richard L Zuerner
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center (NADC), Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Ames, IA, USA
| | - Ami Frank
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center (NADC), Agricultural Research Service (ARS), United States Department of Agriculture (USDA), Ames, IA, USA
| | - Caroline E Cameron
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, BC, Canada
| |
Collapse
|
50
|
The evolution of metabolic networks of E. coli. BMC SYSTEMS BIOLOGY 2011; 5:182. [PMID: 22044664 PMCID: PMC3229490 DOI: 10.1186/1752-0509-5-182] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 11/01/2011] [Indexed: 11/19/2022]
Abstract
Background Despite the availability of numerous complete genome sequences from E. coli strains, published genome-scale metabolic models exist only for two commensal E. coli strains. These models have proven useful for many applications, such as engineering strains for desired product formation, and we sought to explore how constructing and evaluating additional metabolic models for E. coli strains could enhance these efforts. Results We used the genomic information from 16 E. coli strains to generate an E. coli pangenome metabolic network by evaluating their collective 76,990 ORFs. Each of these ORFs was assigned to one of 17,647 ortholog groups including ORFs associated with reactions in the most recent metabolic model for E. coli K-12. For orthologous groups that contain an ORF already represented in the MG1655 model, the gene to protein to reaction associations represented in this model could then be easily propagated to other E. coli strain models. All remaining orthologous groups were evaluated to see if new metabolic reactions could be added to generate a pangenome-scale metabolic model (iEco1712_pan). The pangenome model included reactions from a metabolic model update for E. coli K-12 MG1655 (iEco1339_MG1655) and enabled development of five additional strain-specific genome-scale metabolic models. These additional models include a second K-12 strain (iEco1335_W3110) and four pathogenic strains (two enterohemorrhagic E. coli O157:H7 and two uropathogens). When compared to the E. coli K-12 models, the metabolic models for the enterohemorrhagic (iEco1344_EDL933 and iEco1345_Sakai) and uropathogenic strains (iEco1288_CFT073 and iEco1301_UTI89) contained numerous lineage-specific gene and reaction differences. All six E. coli models were evaluated by comparing model predictions to carbon source utilization measurements under aerobic and anaerobic conditions, and to batch growth profiles in minimal media with 0.2% (w/v) glucose. An ancestral genome-scale metabolic model based on conserved ortholog groups in all 16 E. coli genomes was also constructed, reflecting the conserved ancestral core of E. coli metabolism (iEco1053_core). Comparative analysis of all six strain-specific E. coli models revealed that some of the pathogenic E. coli strains possess reactions in their metabolic networks enabling higher biomass yields on glucose. Finally the lineage-specific metabolic traits were compared to the ancestral core model predictions to derive new insight into the evolution of metabolism within this species. Conclusion Our findings demonstrate that a pangenome-scale metabolic model can be used to rapidly construct additional E. coli strain-specific models, and that quantitative models of different strains of E. coli can accurately predict strain-specific phenotypes. Such pangenome and strain-specific models can be further used to engineer metabolic phenotypes of interest, such as designing new industrial E. coli strains.
Collapse
|