1
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Mawla GD, Kamal SM, Cao LY, Purhonen P, Hebert H, Sauer RT, Baker TA, Römling U. The membrane-cytoplasmic linker defines activity of FtsH proteases in Pseudomonas aeruginosa clone C. J Biol Chem 2024; 300:105622. [PMID: 38176647 PMCID: PMC10850787 DOI: 10.1016/j.jbc.2023.105622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 12/22/2023] [Accepted: 12/27/2023] [Indexed: 01/06/2024] Open
Abstract
Pandemic Pseudomonas aeruginosa clone C strains encode two inner-membrane associated ATP-dependent FtsH proteases. PaftsH1 is located on the core genome and supports cell growth and intrinsic antibiotic resistance, whereas PaftsH2, a xenolog acquired through horizontal gene transfer from a distantly related species, is unable to functionally replace PaftsH1. We show that purified PaFtsH2 degrades fewer substrates than PaFtsH1. Replacing the 31-amino acid-extended linker region of PaFtsH2 spanning from the C-terminal end of the transmembrane helix-2 to the first seven highly divergent residues of the cytosolic AAA+ ATPase module with the corresponding region of PaFtsH1 improves hybrid-enzyme substrate processing in vitro and enables PaFtsH2 to substitute for PaFtsH1 in vivo. Electron microscopy indicates that the identity of this linker sequence influences FtsH flexibility. We find membrane-cytoplasmic (MC) linker regions of PaFtsH1 characteristically glycine-rich compared to those from FtsH2. Consequently, introducing three glycines into the membrane-proximal end of PaFtsH2's MC linker is sufficient to elevate its activity in vitro and in vivo. Our findings establish that the efficiency of substrate processing by the two PaFtsH isoforms depends on MC linker identity and suggest that greater linker flexibility and/or length allows FtsH to degrade a wider spectrum of substrates. As PaFtsH2 homologs occur across bacterial phyla, we hypothesize that FtsH2 is a latent enzyme but may recognize specific substrates or is activated in specific contexts or biological niches. The identity of such linkers might thus play a more determinative role in the functionality of and physiological impact by FtsH proteases than previously thought.
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Affiliation(s)
- Gina D Mawla
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Shady M Kamal
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm; Sweden
| | - Lian-Ying Cao
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm; Sweden
| | - Pasi Purhonen
- Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, Huddinge; Sweden
| | - Hans Hebert
- Department of Biomedical Engineering and Health Systems, KTH Royal Institute of Technology, Huddinge; Sweden
| | - Robert T Sauer
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Tania A Baker
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA.
| | - Ute Römling
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm; Sweden.
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2
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Osgerby A, Overton TW. Approaches for high-throughput quantification of periplasmic recombinant proteins. N Biotechnol 2023; 77:149-160. [PMID: 37708933 DOI: 10.1016/j.nbt.2023.09.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 09/01/2023] [Accepted: 09/11/2023] [Indexed: 09/16/2023]
Abstract
The Gram-negative periplasm is a convenient location for the accumulation of many recombinant proteins including biopharmaceutical products. It is the site of disulphide bond formation, required by some proteins (such as antibody fragments) for correct folding and function. It also permits simpler protein release and downstream processing than cytoplasmic accumulation. As such, targeting of recombinant proteins to the E. coli periplasm is a key strategy in biologic manufacture. However, expression and translocation of each recombinant protein requires optimisation including selection of the best signal peptide and growth and production conditions. Traditional methods require separation and analysis of protein compositions of periplasmic and cytoplasmic fractions, a time- and labour-intensive method that is difficult to parallelise. Therefore, approaches for high throughput quantification of periplasmic protein accumulation offer advantages in rapid process development.
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Affiliation(s)
- Alexander Osgerby
- School of Chemical Engineering and Institute of Microbiology and Infection, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Tim W Overton
- School of Chemical Engineering and Institute of Microbiology and Infection, The University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
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3
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Xue C, Zhang Y, Li H, Liu Z, Gao W, Liu M, Wang H, Liu P, Zhao J. The genome of Candidatus phytoplasma ziziphi provides insights into their biological characteristics. BMC PLANT BIOLOGY 2023; 23:251. [PMID: 37173622 PMCID: PMC10176825 DOI: 10.1186/s12870-023-04243-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Accepted: 04/22/2023] [Indexed: 05/15/2023]
Abstract
Phytoplasmas are obligate cell wall-less prokaryotic bacteria that primarily multiply in plant phloem tissue. Jujube witches' broom (JWB) associated with phytoplasma is a destructive disease of jujube (Ziziphus jujuba Mill.). Here we report the complete 'Candidatus Phytoplasma ziziphi' chromosome of strain Hebei-2018, which is a circular genome of 764,108-base pairs with 735 predicted CDS. Notably, extra 19,825 bp (from 621,995 to 641,819 bp) compared to the previously reported one complements the genes involved in glycolysis, such as pdhA, pdhB, pdhC, pdhD, ackA, pduL and LDH. The synonymous codon usage bias (CUB) patterns by using comparative genomics analysis among the 9 phytoplasmas were similar for most codons. The ENc-GC3s analysis among the 9 phytoplasmas showed a greater effect under the selection on the CUBs of phytoplasmas genes than mutation and other factors. The genome exhibited a strongly reduced ability in metabolic synthesis, while the genes encoding transporter systems were well developed. The genes involved in sec-dependent protein translocation system were also identified.The expressions of nine FtsHs encoding membrane associated ATP-dependent Zn proteases and Mn-SodA with redox capacity in the Ca. P. ziziphi was positively correlated with the phytoplasma concentration. Taken together, the genome will not only expand the number of phytoplasma species and provide some new information about Ca. P. ziziphi, but also contribute to exploring its pathogenic mechanism.
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Affiliation(s)
- Chaoling Xue
- College of Life Science, Hebei Agricultural University, Baoding, 071000, China
- Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, Hebei Agricultural University, Baoding, 071000, China
| | - Yao Zhang
- College of Life Science, Hebei Agricultural University, Baoding, 071000, China
- Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, Hebei Agricultural University, Baoding, 071000, China
| | - Hongtai Li
- College of Life Science, Hebei Agricultural University, Baoding, 071000, China
- Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, Hebei Agricultural University, Baoding, 071000, China
| | - Zhiguo Liu
- Research Center of Chinese Jujube, Hebei Agricultural University, Baoding, 071000, China
| | - Weilin Gao
- College of Life Science, Hebei Agricultural University, Baoding, 071000, China
- Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, Hebei Agricultural University, Baoding, 071000, China
| | - Mengjun Liu
- Research Center of Chinese Jujube, Hebei Agricultural University, Baoding, 071000, China
| | - Huibin Wang
- College of Life Science, Hebei Agricultural University, Baoding, 071000, China
| | - Ping Liu
- Research Center of Chinese Jujube, Hebei Agricultural University, Baoding, 071000, China.
| | - Jin Zhao
- College of Life Science, Hebei Agricultural University, Baoding, 071000, China.
- Key Laboratory of Hebei Province for Plant Physiology and Molecular Pathology, Hebei Agricultural University, Baoding, 071000, China.
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4
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Liu L, Law COK, Nie Q, Pham HQ, Ma H, Zhang L, Ho PL, Lau TCK. Comparative analysis of outer membrane vesicles from uropathogenic Escherichia coli reveal the role of aromatic amino acids synthesis proteins in motility. Int J Med Microbiol 2023; 313:151573. [PMID: 36634604 DOI: 10.1016/j.ijmm.2023.151573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 12/15/2022] [Accepted: 01/05/2023] [Indexed: 01/09/2023] Open
Abstract
Uropathogenic Escherichia coli (UPEC) are causative agent that causes urinary tract infections (UTIs) and the recent emergence of multidrug resistance (MDR) of UPEC increases the burden on the community. Recent studies of bacterial outer membrane vesicles (OMV) identified various factors including proteins, nucleic acids, and small molecules which provided inter-cellular communication within the bacterial population. However, the components of UPEC-specific OMVs and their functional role remain unclear. Here, we systematically determined the proteomes of UPEC-OMVs and identified the specific components that provide functions to the recipient bacteria. Based on the functional network of OMVs' proteomes, a group of signaling peptides was found in all OMVs which provide communication among bacteria. Moreover, we demonstrated that treatment with UPEC-OMVs affected the motility and biofilm formation of the recipient bacteria, and further identified aromatic amino acid (AAA) biosynthesis proteins as the key factors to provide their movement.
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Affiliation(s)
- LiangZhe Liu
- Department of Biomedical Sciences, College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region; Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518000, China; Center for Clinical Precision Pharmacy, The First Affiliated Hospital of Guangdong Pharmaceutical University, Guangzhou, China; School of Clinical Pharmacy, Guangdong Pharmaceutical University, Guangzhou, China
| | - Carmen Oi Kwan Law
- Department of Biomedical Sciences, College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region; Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518000, China
| | - Qichang Nie
- Department of Biomedical Sciences, College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region; Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518000, China
| | - Hoa Quynh Pham
- Department of Biomedical Sciences, College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region; Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518000, China
| | - Haiying Ma
- Department of Biomedical Sciences, College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region
| | - Liang Zhang
- Department of Biomedical Sciences, College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region
| | - Pak Leung Ho
- Department of Microbiology, Queen Mary Hospital, University of Hong Kong, Hong Kong Special Administrative Region
| | - Terrence Chi-Kong Lau
- Department of Biomedical Sciences, College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon, Hong Kong Special Administrative Region; Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute, City University of Hong Kong, Shenzhen 518000, China.
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5
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Miyazaki R, Ai M, Tanaka N, Suzuki T, Dhomae N, Tsukazaki T, Akiyama Y, Mori H. Inner membrane YfgM–PpiD heterodimer acts as a functional unit that associates with the SecY/E/G translocon and promotes protein translocation. J Biol Chem 2022; 298:102572. [PMID: 36209828 PMCID: PMC9643414 DOI: 10.1016/j.jbc.2022.102572] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 09/24/2022] [Accepted: 09/29/2022] [Indexed: 11/06/2022] Open
Abstract
PpiD and YfgM are inner membrane proteins that are both composed of an N-terminal transmembrane segment and a C-terminal periplasmic domain. Escherichia coli YfgM and PpiD form a stable complex that interacts with the SecY/E/G (Sec) translocon, a channel that allows protein translocation across the cytoplasmic membrane. Although PpiD is known to function in protein translocation, the functional significance of PpiD–YfgM complex formation as well as the molecular mechanisms of PpiD–YfgM and PpiD/YfgM–Sec translocon interactions remain unclear. Here, we conducted genetic and biochemical studies using yfgM and ppiD mutants and demonstrated that a lack of YfgM caused partial PpiD degradation at its C-terminal region and hindered the membrane translocation of Vibrio protein export monitoring polypeptide (VemP), a Vibrio secretory protein, in both E. coli and Vibrio alginolyticus. While ppiD disruption also impaired VemP translocation, we found that the yfgM and ppiD double deletion exhibited no additive or synergistic effects. Together, these results strongly suggest that both PpiD and YfgM are required for efficient VemP translocation. Furthermore, our site-directed in vivo photocrosslinking analysis revealed that the tetratricopeptide repeat domain of YfgM and a conserved structural domain (NC domain) in PpiD interact with each other and that YfgM, like PpiD, directly interacts with the SecG translocon subunit. Crosslinking analysis also suggested that PpiD–YfgM complex formation is required for these proteins to interact with SecG. In summary, we propose that PpiD and YfgM form a functional unit that stimulates protein translocation by facilitating their proper interactions with the Sec translocon.
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Affiliation(s)
- Ryoji Miyazaki
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Mengting Ai
- Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Natsuko Tanaka
- Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Takehiro Suzuki
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Saitama, Japan
| | - Naoshi Dhomae
- Biomolecular Characterization Unit, RIKEN Center for Sustainable Resource Science, Saitama, Japan
| | - Tomoya Tsukazaki
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Yoshinori Akiyama
- Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Hiroyuki Mori
- Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan.
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6
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Watkins DW, Williams SL, Collinson I. A bacterial secretosome for regulated envelope biogenesis and quality control? MICROBIOLOGY (READING, ENGLAND) 2022; 168. [PMID: 36260397 DOI: 10.1099/mic.0.001255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The Gram-negative bacterial envelope is the first line of defence against environmental stress and antibiotics. Therefore, its biogenesis is of considerable fundamental interest, as well as a challenge to address the growing problem of antimicrobial resistance. All bacterial proteins are synthesised in the cytosol, so inner- and outer-membrane proteins, and periplasmic residents have to be transported to their final destinations via specialised protein machinery. The Sec translocon, a ubiquitous integral inner-membrane (IM) complex, is key to this process as the major gateway for protein transit from the cytosol to the cell envelope; this can be achieved during their translation, or afterwards. Proteins need to be directed into the inner-membrane (usually co-translational), otherwise SecA utilises ATP and the proton-motive-force (PMF) to drive proteins across the membrane post-translationally. These proteins are then picked up by chaperones for folding in the periplasm, or delivered to the β-barrel assembly machinery (BAM) for incorporation into the outer-membrane. The core hetero-trimeric SecYEG-complex forms the hub for an extensive network of interactions that regulate protein delivery and quality control. Here, we conduct a biochemical exploration of this 'secretosome' -a very large, versatile and inter-changeable assembly with the Sec-translocon at its core; featuring interactions that facilitate secretion (SecDF), inner- and outer-membrane protein insertion (respectively, YidC and BAM), protein folding and quality control (e.g. PpiD, YfgM and FtsH). We propose the dynamic interplay amongst these, and other factors, act to ensure efficient envelope biogenesis, regulated to accommodate the requirements of cell elongation and division. We believe this organisation is critical for cell wall biogenesis and remodelling and thus its perturbation could be a means for the development of anti-microbials.
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Affiliation(s)
- Daniel W Watkins
- School of Biochemistry, University of Bristol, BS8 1TD, UK.,Present address: CytoSeek, Science Creates Old Market, Midland Road, Bristol, BS20JZ, UK
| | | | - Ian Collinson
- School of Biochemistry, University of Bristol, BS8 1TD, UK
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7
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Imaizumi Y, Takanuki K, Miyake T, Takemoto M, Hirata K, Hirose M, Oi R, Kobayashi T, Miyoshi K, Aruga R, Yokoyama T, Katagiri S, Matsuura H, Iwasaki K, Kato T, Kaneko MK, Kato Y, Tajiri M, Akashi S, Nureki O, Hizukuri Y, Akiyama Y, Nogi T. Mechanistic insights into intramembrane proteolysis by E. coli site-2 protease homolog RseP. SCIENCE ADVANCES 2022; 8:eabp9011. [PMID: 36001659 PMCID: PMC9401612 DOI: 10.1126/sciadv.abp9011] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 07/01/2022] [Indexed: 05/31/2023]
Abstract
Site-2 proteases are a conserved family of intramembrane proteases that cleave transmembrane substrates to regulate signal transduction and maintain proteostasis. Here, we elucidated crystal structures of inhibitor-bound forms of bacterial site-2 proteases including Escherichia coli RseP. Structure-based chemical modification and cross-linking experiments indicated that the RseP domains surrounding the active center undergo conformational changes to expose the substrate-binding site, suggesting that RseP has a gating mechanism to regulate substrate entry. Furthermore, mutational analysis suggests that a conserved electrostatic linkage between the transmembrane and peripheral membrane-associated domains mediates the conformational changes. In vivo cleavage assays also support that the substrate transmembrane helix is unwound by strand addition to the intramembrane β sheet of RseP and is clamped by a conserved asparagine residue at the active center for efficient cleavage. This mechanism underlying the substrate binding, i.e., unwinding and clamping, appears common across distinct families of intramembrane proteases that cleave transmembrane segments.
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Affiliation(s)
- Yuki Imaizumi
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Kazunori Takanuki
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Takuya Miyake
- Institute for Life and Medical Sciences, Kyoto University, 53 Shogoinkawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Mizuki Takemoto
- Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kunio Hirata
- Life Science Research Infrastructure Group, RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Mika Hirose
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Rika Oi
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Tatsuya Kobayashi
- Institute for Life and Medical Sciences, Kyoto University, 53 Shogoinkawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Kenichi Miyoshi
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Rie Aruga
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Tatsuhiko Yokoyama
- Institute for Life and Medical Sciences, Kyoto University, 53 Shogoinkawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Shizuka Katagiri
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Hiroaki Matsuura
- Life Science Research Infrastructure Group, RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Kenji Iwasaki
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance (TARA), University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8577, Japan
| | - Takayuki Kato
- Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - Mika K. Kaneko
- Department of Antibody Drug Development, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Sendai, Miyagi 980-8575, Japan
| | - Yukinari Kato
- Department of Antibody Drug Development, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Sendai, Miyagi 980-8575, Japan
- Department of Molecular Pharmacology, Tohoku University Graduate School of Medicine, 2-1 Seiryo-machi, Sendai, Miyagi 980-8575, Japan
| | - Michiko Tajiri
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Satoko Akashi
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
| | - Osamu Nureki
- Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yohei Hizukuri
- Institute for Life and Medical Sciences, Kyoto University, 53 Shogoinkawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Yoshinori Akiyama
- Institute for Life and Medical Sciences, Kyoto University, 53 Shogoinkawahara-cho, Sakyo-ku, Kyoto 606-8507, Japan
| | - Terukazu Nogi
- Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro-cho, Tsurumi-ku, Yokohama 230-0045, Japan
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8
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Shu S, Mi W. Regulatory mechanisms of lipopolysaccharide synthesis in Escherichia coli. Nat Commun 2022; 13:4576. [PMID: 35931690 PMCID: PMC9356133 DOI: 10.1038/s41467-022-32277-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 07/25/2022] [Indexed: 11/09/2022] Open
Abstract
Lipopolysaccharide (LPS) is an essential glycolipid and forms a protective permeability barrier for most Gram-negative bacteria. In E. coli, LPS levels are under feedback control, achieved by FtsH-mediated degradation of LpxC, which catalyzes the first committed step in LPS synthesis. FtsH is a membrane-bound AAA+ protease, and its protease activity toward LpxC is regulated by essential membrane proteins LapB and YejM. However, the regulatory mechanisms are elusive. We establish an in vitro assay to analyze the kinetics of LpxC degradation and demonstrate that LapB is an adaptor protein that utilizes its transmembrane helix to interact with FtsH and its cytoplasmic domains to recruit LpxC. Our YejM/LapB complex structure reveals that YejM is an anti-adaptor protein, competing with FtsH for LapB to inhibit LpxC degradation. Structural analysis unravels that LapB and LPS have overlapping binding sites in YejM. Thus, LPS levels control formation of the YejM/LapB complex to determine LpxC protein levels.
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Affiliation(s)
- Sheng Shu
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Wei Mi
- Department of Pharmacology, Yale University School of Medicine, New Haven, CT, 06520, USA. .,Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, 06520, USA.
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9
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Qiao Z, Yokoyama T, Yan XF, Beh IT, Shi J, Basak S, Akiyama Y, Gao YG. Cryo-EM structure of the entire FtsH-HflKC AAA protease complex. Cell Rep 2022; 39:110890. [PMID: 35649372 DOI: 10.1016/j.celrep.2022.110890] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/25/2022] [Accepted: 05/06/2022] [Indexed: 11/03/2022] Open
Abstract
The membrane-bound AAA protease FtsH is the key player controlling protein quality in bacteria. Two single-pass membrane proteins, HflK and HflC, interact with FtsH to modulate its proteolytic activity. Here, we present structure of the entire FtsH-HflKC complex, comprising 12 copies of both HflK and HflC, all of which interact reciprocally to form a cage, as well as four FtsH hexamers with periplasmic domains and transmembrane helices enclosed inside the cage and cytoplasmic domains situated at the base of the cage. FtsH K61/D62/S63 in the β2-β3 loop in the periplasmic domain directly interact with HflK, contributing to complex formation. Pull-down and in vivo enzymatic activity assays validate the importance of the interacting interface for FtsH-HflKC complex formation. Structural comparison with the substrate-bound human m-AAA protease AFG3L2 offers implications for the HflKC cage in modulating substrate access to FtsH. Together, our findings provide a better understanding of FtsH-type AAA protease holoenzyme assembly and regulation.
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Affiliation(s)
- Zhu Qiao
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore; NTU Institute of Structural Biology, Nanyang Technological University, Singapore 639798, Singapore
| | - Tatsuhiko Yokoyama
- Institute for Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Xin-Fu Yan
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore; NTU Institute of Structural Biology, Nanyang Technological University, Singapore 639798, Singapore
| | - Ing Tsyr Beh
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Jian Shi
- Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
| | - Sandip Basak
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Yoshinori Akiyama
- Institute for Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan.
| | - Yong-Gui Gao
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore; NTU Institute of Structural Biology, Nanyang Technological University, Singapore 639798, Singapore.
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10
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The Wsp system of Pseudomonas aeruginosa links surface sensing and cell envelope stress. Proc Natl Acad Sci U S A 2022; 119:e2117633119. [PMID: 35476526 PMCID: PMC9170161 DOI: 10.1073/pnas.2117633119] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
SignificanceBacteria must respond quickly to environmental changes to survive. One way bacteria can respond to environmental stress is by undergoing a lifestyle transition from individual, free-swimming cells to a surface-associated community called a biofilm characterized by aggregative growth. The opportunistic pathogen Pseudomonas aeruginosa uses the Wsp chemosensory system to sense an unknown surface-associated cue. Here we show that the Wsp system senses cell envelope stress, specifically conditions that promote unfolded or misregulated periplasmic and inner membrane proteins. This work provides direct evidence that cell envelope stress is an important feature of surface sensing in P. aeruginosa.
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11
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Whitman BT, Murray CRA, Whitford DS, Paul SS, Fahlman RP, Glover MJN, Owttrim GW. Degron-mediated proteolysis of CrhR-like DEAD-box RNA helicases in cyanobacteria. J Biol Chem 2022; 298:101925. [PMID: 35413287 PMCID: PMC9117542 DOI: 10.1016/j.jbc.2022.101925] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 04/01/2022] [Accepted: 04/02/2022] [Indexed: 11/18/2022] Open
Abstract
Conditional proteolytic degradation is an irreversible and highly regulated process that fulfills crucial regulatory functions in all organisms. As proteolytic targets tend to be critical metabolic or regulatory proteins, substrates are targeted for degradation only under appropriate conditions through the recognition of an amino acid sequence referred to as a “degron”. DEAD-box RNA helicases mediate all aspects of RNA metabolism, contributing to cellular fitness. However, the mechanism by which abiotic-stress modulation of protein stability regulates bacterial helicase abundance has not been extensively characterized. Here, we provide in vivo evidence that proteolytic degradation of the cyanobacterial DEAD-box RNA helicase CrhR is conditional, being initiated by a temperature upshift from 20 to 30 °C in the model cyanobacterium, Synechocystis sp. PCC 6803. We show degradation requires a unique, highly conserved, inherently bipartite degron located in the C-terminal extension found only in CrhR-related RNA helicases in the phylum Cyanobacteria. However, although necessary, the degron is not sufficient for proteolysis, as disruption of RNA helicase activity and/or translation inhibits degradation. These results suggest a positive feedback mechanism involving a role for CrhR in expression of a crucial factor required for degradation. Furthermore, AlphaFold structural prediction indicated the C-terminal extension is a homodimerization domain with homology to other bacterial RNA helicases, and mass photometry data confirmed that CrhR exists as a dimer in solution at 22 °C. These structural data suggest a model wherein the CrhR degron is occluded at the dimerization interface but could be exposed if dimerization was disrupted by nonpermissive conditions.
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Affiliation(s)
- Brendan T Whitman
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Cameron R A Murray
- Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Denise S Whitford
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Simanta S Paul
- Department of Physics, University of Alberta, Edmonton, Alberta, Canada
| | - Richard P Fahlman
- Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Mark J N Glover
- Department of Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - George W Owttrim
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
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12
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Ma C, Wang C, Luo D, Yan L, Yang W, Li N, Gao N. Structural insights into the membrane microdomain organization by SPFH family proteins. Cell Res 2022; 32:176-189. [PMID: 34975153 PMCID: PMC8807802 DOI: 10.1038/s41422-021-00598-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Accepted: 11/09/2021] [Indexed: 02/03/2023] Open
Abstract
The lateral segregation of membrane constituents into functional microdomains, conceptually known as lipid raft, is a universal organization principle for cellular membranes in both prokaryotes and eukaryotes. The widespread Stomatin, Prohibitin, Flotillin, and HflK/C (SPFH) family proteins are enriched in functional membrane microdomains at various subcellular locations, and therefore were hypothesized to play a scaffolding role in microdomain formation. In addition, many SPFH proteins are also implicated in highly specific processes occurring on the membrane. However, none of these functions is understood at the molecular level. Here we report the structure of a supramolecular complex that is isolated from bacterial membrane microdomains and contains two SPFH proteins (HflK and HflC) and a membrane-anchored AAA+ protease FtsH. HflK and HflC form a circular 24-mer assembly, featuring a laterally segregated membrane microdomain (20 nm in diameter) bordered by transmembrane domains of HflK/C and a completely sealed periplasmic vault. Four FtsH hexamers are embedded inside this microdomain through interactions with the inner surface of the vault. These observations provide a mechanistic explanation for the role of HflK/C and their mitochondrial homologs prohibitins in regulating membrane-bound AAA+ proteases, and suggest a general model for the organization and functionalization of membrane microdomains by SPFH proteins.
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Affiliation(s)
- Chengying Ma
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Chengkun Wang
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Dingyi Luo
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Lu Yan
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Wenxian Yang
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Ningning Li
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China
| | - Ning Gao
- grid.11135.370000 0001 2256 9319State Key Laboratory of Membrane Biology, Peking-Tsinghua Joint Centre for Life Sciences, School of Life Sciences, Peking University, Beijing, China ,grid.11135.370000 0001 2256 9319National Biomedical Imaging Center, Peking University, Beijing, China
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13
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Tsviklist V, Guest RL, Raivio TL. The Cpx Stress Response Regulates Turnover of Respiratory Chain Proteins at the Inner Membrane of Escherichia coli. Front Microbiol 2022; 12:732288. [PMID: 35154019 PMCID: PMC8831704 DOI: 10.3389/fmicb.2021.732288] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 12/20/2021] [Indexed: 12/03/2022] Open
Abstract
The Cpx envelope stress response is a major signaling pathway monitoring bacterial envelope integrity, activated both internally by excessive synthesis of membrane proteins and externally by a variety of environmental cues. The Cpx regulon is enriched with genes coding for protein folding and degrading factors, virulence determinants, and large envelope-localized complexes. Transcriptional repression of the two electron transport chain complexes, NADH dehydrogenase I and cytochrome bo3, by the Cpx pathway has been demonstrated, however, there is evidence that additional regulatory mechanisms exist. In this study, we examine the interaction between Cpx-regulated protein folding and degrading factors and the respiratory complexes NADH dehydrogenase I and succinate dehydrogenase in Escherichia coli. Here we show that the cellular need for Cpx-mediated stress adaptation increases when respiratory complexes are more prevalent or active, which is demonstrated by the growth defect of Cpx-deficient strains on media that requires a functional electron transport chain. Interestingly, deletion of several Cpx-regulated proteolytic factors and chaperones results in similar growth-deficient phenotypes. Furthermore, we find that the stability of the NADH dehydrogenase I protein complex is lower in cells with a functional Cpx response, while in its absence, protein turnover is impaired. Finally, we demonstrated that the succinate dehydrogenase complex has reduced activity in E. coli lacking the Cpx pathway. Our results suggest that the Cpx two-component system serves as a sentry of inner membrane protein biogenesis, ensuring the function of large envelope protein complexes and maintaining the cellular energy status of the cell.
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Affiliation(s)
- Valeria Tsviklist
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Randi L. Guest
- Lewis Thomas Laboratory, Department of Molecular Biology, Princeton University, Princeton, NJ, United States
| | - Tracy L. Raivio
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
- *Correspondence: Tracy L. Raivio,
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14
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Yi L, Liu B, Nixon PJ, Yu J, Chen F. Recent Advances in Understanding the Structural and Functional Evolution of FtsH Proteases. FRONTIERS IN PLANT SCIENCE 2022; 13:837528. [PMID: 35463435 PMCID: PMC9020784 DOI: 10.3389/fpls.2022.837528] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 02/24/2022] [Indexed: 05/18/2023]
Abstract
The FtsH family of proteases are membrane-anchored, ATP-dependent, zinc metalloproteases. They are universally present in prokaryotes and the mitochondria and chloroplasts of eukaryotic cells. Most bacteria bear a single ftsH gene that produces hexameric homocomplexes with diverse house-keeping roles. However, in mitochondria, chloroplasts and cyanobacteria, multiple FtsH homologs form homo- and heterocomplexes with specialized functions in maintaining photosynthesis and respiration. The diversification of FtsH homologs combined with selective pairing of FtsH isomers is a versatile strategy to enable functional adaptation. In this article we summarize recent progress in understanding the evolution, structure and function of FtsH proteases with a focus on the role of FtsH in photosynthesis and respiration.
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Affiliation(s)
- Lanbo Yi
- Institute for Food and Bioresource Engineering, College of Engineering, Peking University, Beijing, China
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, China
| | - Bin Liu
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, China
| | - Peter J. Nixon
- Sir Ernst Chain Building-Wolfson Laboratories, Department of Life Sciences, Imperial College London, London, United Kingdom
- *Correspondence: Peter J. Nixon, ; orcid.org/0000-0003-1952-6937
| | - Jianfeng Yu
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, China
- Sir Ernst Chain Building-Wolfson Laboratories, Department of Life Sciences, Imperial College London, London, United Kingdom
- Jianfeng Yu, ; orcid.org/0000-0001-7174-3803
| | - Feng Chen
- Shenzhen Key Laboratory of Marine Microbiome Engineering, Institute for Advanced Study, Shenzhen University, Shenzhen, China
- Institute for Innovative Development of Food Industry, Shenzhen University, Shenzhen, China
- Feng Chen, ; orcid.org/0000-0002-9054-943X
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15
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Miyazaki R, Mori H, Akiyama Y. A Photo-Crosslinking Approach to Monitoring the Assembly of an LptD Intermediate with LptE in a Living Cell. Methods Mol Biol 2022; 2548:97-107. [PMID: 36151494 DOI: 10.1007/978-1-0716-2581-1_7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Elucidating the dynamic behavior of proteins in living cells is extremely important for understanding the physiological roles of biological processes. The site-specific in vivo photo-crosslinking approach using a photoreactive unnatural amino acid enables the analysis of protein interactions with high spatial resolution in vivo. Recently, by improving the photo-crosslinking technique, we developed the "PiXie" method for the analysis of dynamic interactions of newly synthesized proteins. Here, we describe the detailed protocols of the "PiXie" method and its application to the analysis of the assembly processes of the lipopolysaccharide translocon components, a β-barrel outer membrane protein, LptD, and a lipoprotein, LptE.
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Affiliation(s)
- Ryoji Miyazaki
- Nara Institute of Science and Technology, Ikoma, Nara, Japan
| | - Hiroyuki Mori
- Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Yoshinori Akiyama
- Institute for Life and Medical Sciences, Kyoto University, Kyoto, Japan.
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16
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Karyolaimos A, de Gier JW. Strategies to Enhance Periplasmic Recombinant Protein Production Yields in Escherichia coli. Front Bioeng Biotechnol 2021; 9:797334. [PMID: 34970535 PMCID: PMC8712718 DOI: 10.3389/fbioe.2021.797334] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 11/24/2021] [Indexed: 11/29/2022] Open
Abstract
Main reasons to produce recombinant proteins in the periplasm of E. coli rather than in its cytoplasm are to -i- enable disulfide bond formation, -ii- facilitate protein isolation, -iii- control the nature of the N-terminus of the mature protein, and -iv- minimize exposure to cytoplasmic proteases. However, hampered protein targeting, translocation and folding as well as protein instability can all negatively affect periplasmic protein production yields. Strategies to enhance periplasmic protein production yields have focused on harmonizing secretory recombinant protein production rates with the capacity of the secretory apparatus by transcriptional and translational tuning, signal peptide selection and engineering, increasing the targeting, translocation and periplasmic folding capacity of the production host, preventing proteolysis, and, finally, the natural and engineered adaptation of the production host to periplasmic protein production. Here, we discuss these strategies using notable examples as a thread.
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Affiliation(s)
| | - Jan-Willem de Gier
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
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17
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Potteth US, Upadhyay T, Saini S, Saraogi I. Novel Antibacterial Targets in Protein Biogenesis Pathways. Chembiochem 2021; 23:e202100459. [PMID: 34643994 DOI: 10.1002/cbic.202100459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/12/2021] [Indexed: 11/11/2022]
Abstract
Antibiotic resistance has emerged as a global threat due to the ability of bacteria to quickly evolve in response to the selection pressure induced by anti-infective drugs. Thus, there is an urgent need to develop new antibiotics against resistant bacteria. In this review, we discuss pathways involving bacterial protein biogenesis as attractive antibacterial targets since many of them are essential for bacterial survival and virulence. We discuss the structural understanding of various components associated with bacterial protein biogenesis, which in turn can be utilized for rational antibiotic design. We highlight efforts made towards developing inhibitors of these pathways with insights into future possibilities and challenges. We also briefly discuss other potential targets related to protein biogenesis.
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Affiliation(s)
- Upasana S Potteth
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
| | - Tulsi Upadhyay
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
| | - Snehlata Saini
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India
| | - Ishu Saraogi
- Department of Biological Sciences, Indian Institute of Science Education and Research Bhopal, Bhauri, Bhopal Bypass Road, Bhopal, 462066, Madhya Pradesh, India.,Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhauri, Bhopal Bypass Road, Bhopal - 462066, Madhya Pradesh, India
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18
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Wang W, Jiang J, Chen H, Zhang Y, Liu Q. FtsH is required for protein secretion homeostasis and full bacterial virulence in Edwardsiella piscicida. Microb Pathog 2021; 161:105194. [PMID: 34534640 DOI: 10.1016/j.micpath.2021.105194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 09/13/2021] [Accepted: 09/13/2021] [Indexed: 11/28/2022]
Abstract
Edwardsiella piscicida, as an important pathogen of fish, has caused huge losses in aquaculture. The virulence in E. piscicida has been increasingly concerned, but few studies have focused on the relationship between virulence and protein secretion homeostasis. FtsH, as a member of the AAA protease family, has important cellular functions, such as controlling the quality of membrane proteins. In this study, FtsH was demonstrated to be essential in maintaining protein secretion homeostasis, and its deletion could result in the secretion of massive cytoplasmic proteins by non-classical secretion pathway. Furthermore it was showed that FtsH is vital for E. piscicida to proliferate within host cells, and E. piscicida mutant ΔftsH will be obviously attenuated. After zebrafish was infected with the mutant ΔftsH, the lethality rate for zebrafish and the bacterial colonization in its organs were greatly reduced. These results suggested that FtsH, as a regulatory factor, closely linked protein secretory homeostasis with bacterial virulence, which provided clues for further exploring the involvement of protein secretion homeostasis in bacterial virulence.
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Affiliation(s)
- Wei Wang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Jiatiao Jiang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Hao Chen
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China
| | - Yuanxing Zhang
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), 519000, Zhuhai, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, 200237, China
| | - Qin Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, Shanghai, 200237, China; Shanghai Engineering Research Center of Maricultured Animal Vaccines, Shanghai, 200237, China.
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19
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Miyazaki R, Watanabe T, Yoshitani K, Akiyama Y. Edge-strand of BepA interacts with immature LptD on the β-barrel assembly machine to direct it to on- and off-pathways. eLife 2021; 10:70541. [PMID: 34463613 PMCID: PMC8423444 DOI: 10.7554/elife.70541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Accepted: 08/26/2021] [Indexed: 01/06/2023] Open
Abstract
The outer membrane (OM) of Gram-negative bacteria functions as a selective permeability barrier. Escherichia coli periplasmic Zn-metallopeptidase BepA contributes to the maintenance of OM integrity through its involvement in the biogenesis and degradation of LptD, a β-barrel protein component of the lipopolysaccharide translocon. BepA either promotes the maturation of LptD when it is on the normal assembly pathway (on-pathway) or degrades it when its assembly is compromised (off-pathway). BepA performs these functions probably on the β‐barrel assembly machinery (BAM) complex. However, how BepA recognizes and directs an immature LptD to different pathways remains unclear. Here, we explored the interactions among BepA, LptD, and the BAM complex. We found that the interaction of the BepA edge-strand located adjacent to the active site with LptD was crucial not only for proteolysis but also, unexpectedly, for assembly promotion of LptD. Site-directed crosslinking analyses indicated that the unstructured N-terminal half of the β-barrel-forming domain of an immature LptD contacts with the BepA edge-strand. Furthermore, the C-terminal region of the β-barrel-forming domain of the BepA-bound LptD intermediate interacted with a ‘seam’ strand of BamA, suggesting that BepA recognized LptD assembling on the BAM complex. Our findings provide important insights into the functional mechanism of BepA.
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Affiliation(s)
- Ryoji Miyazaki
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Tetsuro Watanabe
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Kohei Yoshitani
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Yoshinori Akiyama
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
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20
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Harwood CR, Kikuchi Y. The ins and outs of Bacillus proteases: activities, functions and commercial significance. FEMS Microbiol Rev 2021; 46:6354784. [PMID: 34410368 PMCID: PMC8767453 DOI: 10.1093/femsre/fuab046] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 08/17/2021] [Indexed: 12/23/2022] Open
Abstract
Because the majority of bacterial species divide by binary fission, and do not have distinguishable somatic and germline cells, they could be considered to be immortal. However, bacteria ‘age’ due to damage to vital cell components such as DNA and proteins. DNA damage can often be repaired using efficient DNA repair mechanisms. However, many proteins have a functional ‘shelf life’; some are short lived, while others are relatively stable. Specific degradation processes are built into the life span of proteins whose activities are required to fulfil a specific function during a prescribed period of time (e.g. cell cycle, differentiation process, stress response). In addition, proteins that are irreparably damaged or that have come to the end of their functional life span need to be removed by quality control proteases. Other proteases are involved in performing a variety of specific functions that can be broadly divided into three categories: processing, regulation and feeding. This review presents a systematic account of the proteases of Bacillus subtilis and their activities. It reviews the proteases found in, or associated with, the cytoplasm, the cell membrane, the cell wall and the external milieu. Where known, the impacts of the deletion of particular proteases are discussed, particularly in relation to industrial applications.
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Affiliation(s)
- Colin R Harwood
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University NE2 4AX, Newcastle upon Tyne, UK
| | - Yoshimi Kikuchi
- Research Institute for Bioscience Products & Fine Chemicals, Ajinomoto Co., Inc., Kawasaki 210-8681, JAPAN
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21
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Izert MA, Klimecka MM, Górna MW. Applications of Bacterial Degrons and Degraders - Toward Targeted Protein Degradation in Bacteria. Front Mol Biosci 2021; 8:669762. [PMID: 34026843 PMCID: PMC8138137 DOI: 10.3389/fmolb.2021.669762] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Accepted: 04/15/2021] [Indexed: 12/28/2022] Open
Abstract
A repertoire of proteolysis-targeting signals known as degrons is a necessary component of protein homeostasis in every living cell. In bacteria, degrons can be used in place of chemical genetics approaches to interrogate and control protein function. Here, we provide a comprehensive review of synthetic applications of degrons in targeted proteolysis in bacteria. We describe recent advances ranging from large screens employing tunable degradation systems and orthogonal degrons, to sophisticated tools and sensors for imaging. Based on the success of proteolysis-targeting chimeras as an emerging paradigm in cancer drug discovery, we discuss perspectives on using bacterial degraders for studying protein function and as novel antimicrobials.
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Affiliation(s)
| | | | - Maria Wiktoria Górna
- Structural Biology Group, Biological and Chemical Research Centre, Department of Chemistry, University of Warsaw, Warsaw, Poland
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22
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Yokoyama T, Niinae T, Tsumagari K, Imami K, Ishihama Y, Hizukuri Y, Akiyama Y. The Escherichia coli S2P intramembrane protease RseP regulates ferric citrate uptake by cleaving the sigma factor regulator FecR. J Biol Chem 2021; 296:100673. [PMID: 33865858 PMCID: PMC8144685 DOI: 10.1016/j.jbc.2021.100673] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/08/2021] [Accepted: 04/14/2021] [Indexed: 02/03/2023] Open
Abstract
Escherichia coli RseP, a member of the site-2 protease family of intramembrane proteases, is involved in the activation of the σE extracytoplasmic stress response and elimination of signal peptides from the cytoplasmic membrane. However, whether RseP has additional cellular functions is unclear. In this study, we used mass spectrometry-based quantitative proteomic analysis to search for new substrates that might reveal unknown physiological roles for RseP. Our data showed that the levels of several Fec system proteins encoded by the fecABCDE operon (fec operon) were significantly decreased in an RseP-deficient strain. The Fec system is responsible for the uptake of ferric citrate, and the transcription of the fec operon is controlled by FecI, an alternative sigma factor, and its regulator FecR, a single-pass transmembrane protein. Assays with a fec operon expression reporter demonstrated that the proteolytic activity of RseP is essential for the ferric citrate-dependent upregulation of the fec operon. Analysis using the FecR protein and FecR-derived model proteins showed that FecR undergoes sequential processing at the membrane and that RseP participates in the last step of this sequential processing to generate the N-terminal cytoplasmic fragment of FecR that participates in the transcription of the fec operon with FecI. A shortened FecR construct was not dependent on RseP for activation, confirming this cleavage step is the essential and sufficient role of RseP. Our study unveiled that E. coli RseP performs the intramembrane proteolysis of FecR, a novel physiological role that is essential for regulating iron uptake by the ferric citrate transport system.
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Affiliation(s)
- Tatsuhiko Yokoyama
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan
| | - Tomoya Niinae
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Kazuya Tsumagari
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Koshi Imami
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Yasushi Ishihama
- Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Yohei Hizukuri
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan.
| | - Yoshinori Akiyama
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto, Japan.
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23
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Oswald J, Njenga R, Natriashvili A, Sarmah P, Koch HG. The Dynamic SecYEG Translocon. Front Mol Biosci 2021; 8:664241. [PMID: 33937339 PMCID: PMC8082313 DOI: 10.3389/fmolb.2021.664241] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Accepted: 03/24/2021] [Indexed: 12/13/2022] Open
Abstract
The spatial and temporal coordination of protein transport is an essential cornerstone of the bacterial adaptation to different environmental conditions. By adjusting the protein composition of extra-cytosolic compartments, like the inner and outer membranes or the periplasmic space, protein transport mechanisms help shaping protein homeostasis in response to various metabolic cues. The universally conserved SecYEG translocon acts at the center of bacterial protein transport and mediates the translocation of newly synthesized proteins into and across the cytoplasmic membrane. The ability of the SecYEG translocon to transport an enormous variety of different substrates is in part determined by its ability to interact with multiple targeting factors, chaperones and accessory proteins. These interactions are crucial for the assisted passage of newly synthesized proteins from the cytosol into the different bacterial compartments. In this review, we summarize the current knowledge about SecYEG-mediated protein transport, primarily in the model organism Escherichia coli, and describe the dynamic interaction of the SecYEG translocon with its multiple partner proteins. We furthermore highlight how protein transport is regulated and explore recent developments in using the SecYEG translocon as an antimicrobial target.
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Affiliation(s)
- Julia Oswald
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert Ludwigs Universität Freiburg, Freiburg, Germany
| | - Robert Njenga
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert Ludwigs Universität Freiburg, Freiburg, Germany.,Faculty of Biology, Albert Ludwigs Universität Freiburg, Freiburg, Germany
| | - Ana Natriashvili
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert Ludwigs Universität Freiburg, Freiburg, Germany.,Faculty of Biology, Albert Ludwigs Universität Freiburg, Freiburg, Germany
| | - Pinku Sarmah
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert Ludwigs Universität Freiburg, Freiburg, Germany.,Faculty of Biology, Albert Ludwigs Universität Freiburg, Freiburg, Germany
| | - Hans-Georg Koch
- Institute for Biochemistry and Molecular Biology, Zentrum für Biochemie und Molekulare Medizin (ZMBZ), Faculty of Medicine, Albert Ludwigs Universität Freiburg, Freiburg, Germany
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24
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Jiang C, Wynne M, Huber D. How Quality Control Systems AID Sec-Dependent Protein Translocation. Front Mol Biosci 2021; 8:669376. [PMID: 33928127 PMCID: PMC8076867 DOI: 10.3389/fmolb.2021.669376] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 03/17/2021] [Indexed: 02/01/2023] Open
Abstract
The evolutionarily conserved Sec machinery is responsible for transporting proteins across the cytoplasmic membrane. Protein substrates of the Sec machinery must be in an unfolded conformation in order to be translocated across (or inserted into) the cytoplasmic membrane. In bacteria, the requirement for unfolded proteins is strict: substrate proteins that fold (or misfold) prematurely in the cytoplasm prior to translocation become irreversibly trapped in the cytoplasm. Partially folded Sec substrate proteins and stalled ribosomes containing nascent Sec substrates can also inhibit translocation by blocking (i.e., “jamming”) the membrane-embedded Sec machinery. To avoid these issues, bacteria have evolved a complex network of quality control systems to ensure that Sec substrate proteins do not fold in the cytoplasm. This quality control network can be broken into three branches, for which we have defined the acronym “AID”: (i) avoidance of cytoplasmic intermediates through cotranslationally channeling newly synthesized Sec substrates to the Sec machinery; (ii) inhibition of folding Sec substrate proteins that transiently reside in the cytoplasm by molecular chaperones and the requirement for posttranslational modifications; (iii) destruction of products that could potentially inhibit translocation. In addition, several stress response pathways help to restore protein-folding homeostasis when environmental conditions that inhibit translocation overcome the AID quality control systems.
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Affiliation(s)
- Chen Jiang
- School of Biosciences and the Institute for Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Max Wynne
- School of Biosciences and the Institute for Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
| | - Damon Huber
- School of Biosciences and the Institute for Microbiology and Infection, University of Birmingham, Birmingham, United Kingdom
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25
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Burgos R, Weber M, Martinez S, Lluch‐Senar M, Serrano L. Protein quality control and regulated proteolysis in the genome-reduced organism Mycoplasma pneumoniae. Mol Syst Biol 2020; 16:e9530. [PMID: 33320415 PMCID: PMC7737663 DOI: 10.15252/msb.20209530] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 11/04/2020] [Accepted: 11/08/2020] [Indexed: 12/14/2022] Open
Abstract
Protein degradation is a crucial cellular process in all-living systems. Here, using Mycoplasma pneumoniae as a model organism, we defined the minimal protein degradation machinery required to maintain proteome homeostasis. Then, we conditionally depleted the two essential ATP-dependent proteases. Whereas depletion of Lon results in increased protein aggregation and decreased heat tolerance, FtsH depletion induces cell membrane damage, suggesting a role in quality control of membrane proteins. An integrative comparative study combining shotgun proteomics and RNA-seq revealed 62 and 34 candidate substrates, respectively. Cellular localization of substrates and epistasis studies supports separate functions for Lon and FtsH. Protein half-life measurements also suggest a role for Lon-modulated protein decay. Lon plays a key role in protein quality control, degrading misfolded proteins and those not assembled into functional complexes. We propose that regulating complex assembly and degradation of isolated proteins is a mechanism that coordinates important cellular processes like cell division. Finally, by considering the entire set of proteases and chaperones, we provide a fully integrated view of how a minimal cell regulates protein folding and degradation.
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Affiliation(s)
- Raul Burgos
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Marc Weber
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Sira Martinez
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Maria Lluch‐Senar
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
| | - Luis Serrano
- Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyBarcelonaSpain
- Universitat Pompeu Fabra (UPF)BarcelonaSpain
- ICREABarcelonaSpain
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26
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Hariharan B, Pross E, Soman R, Kaushik S, Kuhn A, Dalbey RE. Polarity/charge as a determinant of translocase requirements for membrane protein insertion. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1863:183502. [PMID: 33130098 DOI: 10.1016/j.bbamem.2020.183502] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 10/12/2020] [Accepted: 10/21/2020] [Indexed: 11/17/2022]
Abstract
The YidC insertase of Escherichia coli inserts membrane proteins with small periplasmic loops (~20 residues). However, it has difficulty transporting loops that contain positively charged residues compared to negatively charged residues and, as a result, increasing the positive charge has an increased requirement for the Sec machinery as compared to negatively charged loops (Zhu et al., 2013; Soman et al., 2014). This suggested that the polarity and charge of the periplasmic regions of membrane proteins determine the YidC and Sec translocase requirements for insertion. Here we tested this polarity/charge hypothesis by showing that insertion of our model substrate protein procoat-Lep can become YidC/Sec dependent when the periplasmic loop was converted to highly polar even in the absence of any charged residues. Moreover, adding a number of hydrophobic amino acids to a highly polar loop can decrease the Sec-dependence of the otherwise strictly Sec-dependent membrane proteins. We also demonstrate that the length of the procoat-Lep loop is indeed a determinant for Sec-dependence by inserting alanine residues that do not markedly change the overall hydrophilicity of the periplasmic loop. Taken together, the results support the polarity/charge hypothesis as a determinant for the translocase requirement for procoat insertion.
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Affiliation(s)
- Balasubramani Hariharan
- Dept. of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, United States of America
| | - Eva Pross
- Institute of Biology, University of Hohenheim, Stuttgart 70599, Germany
| | - Raunak Soman
- Dept. of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, United States of America
| | - Sharbani Kaushik
- Dept. of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, United States of America
| | - Andreas Kuhn
- Institute of Biology, University of Hohenheim, Stuttgart 70599, Germany
| | - Ross E Dalbey
- Dept. of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, United States of America.
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27
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Lon Protease Removes Excess Signal Recognition Particle Protein in Escherichia coli. J Bacteriol 2020; 202:JB.00161-20. [PMID: 32366590 DOI: 10.1128/jb.00161-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 04/15/2020] [Indexed: 12/12/2022] Open
Abstract
Correct targeting of membrane proteins is essential for membrane integrity, cell physiology, and viability. Cotranslational targeting depends on the universally conserved signal recognition particle (SRP), which is a ribonucleoprotein complex comprised of the protein component Ffh and the 4.5S RNA in Escherichia coli About 25 years ago it was reported that Ffh is an unstable protein, but the underlying mechanism has never been explored. Here, we show that Lon is the primary protease responsible for adjusting the cellular Ffh level. When overproduced, Ffh is particularly prone to degradation during transition from exponential to stationary growth and the cellular Ffh amount is lowest in stationary phase. The Ffh protein consists of two domains, the NG domain, responsible for GTP hydrolysis and docking to the membrane receptor FtsY, and the RNA-binding M domain. We find that the NG domain alone is stable, whereas the isolated M domain is degraded. Consistent with the importance of Lon in this process, the M domain confers synthetic lethality to the lon mutant. The Ffh homolog from the model plant Arabidopsis thaliana, which forms a protein-protein complex rather than a protein-RNA complex, is stable, suggesting that the RNA-binding ability residing in the M domain of E. coli Ffh is important for proteolysis. Our results support a model in which excess Ffh not bound to 4.5S RNA is subjected to proteolysis until an appropriate Ffh concentration is reached. The differential proteolysis adjusts Ffh levels to the cellular demand and maintains cotranslational protein transport and membrane integrity.IMPORTANCE Since one-third of all bacterial proteins reside outside the cytoplasm, protein targeting to the appropriate address is an essential process. Cotranslational targeting to the membrane relies on the signal recognition particle (SRP), which is a protein-RNA complex in bacteria. We report that the protein component Ffh is a substrate of the Lon protease. Regulated proteolysis of Ffh provides a simple mechanism to adjust the concentration of the essential protein to the cellular demand. This is important because elevated or depleted SRP levels negatively impact protein targeting and bacterial fitness.
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28
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Liu G, Beaton SE, Grieve AG, Evans R, Rogers M, Strisovsky K, Armstrong FA, Freeman M, Exley RM, Tang CM. Bacterial rhomboid proteases mediate quality control of orphan membrane proteins. EMBO J 2020; 39:e102922. [PMID: 32337752 PMCID: PMC7232013 DOI: 10.15252/embj.2019102922] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 03/17/2020] [Accepted: 03/24/2020] [Indexed: 02/01/2023] Open
Abstract
Although multiprotein membrane complexes play crucial roles in bacterial physiology and virulence, the mechanisms governing their quality control remain incompletely understood. In particular, it is not known how unincorporated, orphan components of protein complexes are recognised and eliminated from membranes. Rhomboids, the most widespread and largest superfamily of intramembrane proteases, are known to play key roles in eukaryotes. In contrast, the function of prokaryotic rhomboids has remained enigmatic. Here, we show that the Shigella sonnei rhomboid proteases GlpG and the newly identified Rhom7 are involved in membrane protein quality control by specifically targeting components of respiratory complexes, with the metastable transmembrane domains (TMDs) of rhomboid substrates protected when they are incorporated into a functional complex. Initial cleavage by GlpG or Rhom7 allows subsequent degradation of the orphan substrate. Given the occurrence of this strategy in an evolutionary ancient organism and the presence of rhomboids in all domains of life, it is likely that this form of quality control also mediates critical events in eukaryotes and protects cells from the damaging effects of orphan proteins.
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Affiliation(s)
- Guangyu Liu
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Stephen E Beaton
- Inorganic Chemistry Laboratory, University of Oxford, Oxford, UK
| | - Adam G Grieve
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Rhiannon Evans
- Inorganic Chemistry Laboratory, University of Oxford, Oxford, UK
| | - Miranda Rogers
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Kvido Strisovsky
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Praha 6, Czech Republic
| | | | - Matthew Freeman
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Rachel M Exley
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
| | - Christoph M Tang
- Sir William Dunn School of Pathology, University of Oxford, Oxford, UK
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29
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Yoshitani K, Hizukuri Y, Akiyama Y. An in vivo protease activity assay for investigating the functions of the Escherichia coli membrane protease HtpX. FEBS Lett 2019; 593:842-851. [PMID: 30903618 DOI: 10.1002/1873-3468.13368] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 03/14/2019] [Accepted: 03/14/2019] [Indexed: 11/06/2022]
Abstract
Escherichia coli HtpX is an M48 family zinc metalloproteinase located in the cytoplasmic membrane. Previous studies suggested that it is involved in the quality control of membrane proteins. However, its in vivo proteolytic function has not been characterized in detail, mainly because the physiological substrates have not been identified and no model substrate that allows sensitive detection of the protease activity is available. We constructed a new model substrate of HtpX and established an in vivo semiquantitative and convenient protease activity assay system for HtpX. This system enables detection of differential protease activities of HtpX mutants carrying mutations in conserved regions. This system would also be useful for investigating the functions of HtpX and its homologs in other bacteria.
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Affiliation(s)
- Kohei Yoshitani
- Institute for Frontier Life and Medical Sciences, Kyoto University, Japan
| | - Yohei Hizukuri
- Institute for Frontier Life and Medical Sciences, Kyoto University, Japan
| | - Yoshinori Akiyama
- Institute for Frontier Life and Medical Sciences, Kyoto University, Japan
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30
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Marcus EA, Sachs G, Scott DR. Acid-regulated gene expression of Helicobacter pylori: Insight into acid protection and gastric colonization. Helicobacter 2018; 23:e12490. [PMID: 29696729 PMCID: PMC5980792 DOI: 10.1111/hel.12490] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND The pathogen Helicobacter pylori encounters many stressors as it transits to and infects the gastric epithelium. Gastric acidity is the predominate stressor encountered by the bacterium during initial infection and establishment of persistent infection. H. pylori initiates a rapid response to acid to maintain intracellular pH and proton motive force appropriate for a neutralophile. However, acid sensing by H. pylori may also serve as a transcriptional trigger to increase the levels of other pathogenic factors needed to subvert host defenses such as acid acclimation, antioxidants, flagellar synthesis and assembly, and CagA secretion. MATERIALS AND METHODS Helicobacter pylori were acid challenged at pH 3.0, 4.5, 6.0 vs nonacidic pH for 4 hours in the presence of urea, followed by RNA-seq analysis and qPCR. Cytoplasmic pH was monitored under the same conditions. RESULTS About 250 genes were induced, and an equal number were repressed at acidic pHs. Genes encoding for antioxidant proteins, flagellar structural proteins, particularly class 2 genes, T4SS/Cag-PAI, Fo F1 -ATPase, and proteins involved in acid acclimation were highly expressed at acidic pH. Cytoplasmic pH decreased from 7.8 at pHout of 8.0 to 6.0 at pHout of 3.0. CONCLUSIONS These results suggest that increasing extracellular or intracellular acidity or both are detected by the bacterium and serve as a signal to initiate increased production of protective and pathogenic factors needed to counter host defenses for persistent infection. These changes are dependent on degree of acidity and time of acid exposure, triggering a coordinated response to the environment required for colonization.
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Affiliation(s)
- Elizabeth A. Marcus
- Department of Pediatrics, David Geffen School of Medicine at UCLA,VA GLAHS, Los Angeles, CA
| | - George Sachs
- Department Medicine, David Geffen School of Medicine at UCLA,Department Physiology, David Geffen School of Medicine at UCLA,VA GLAHS, Los Angeles, CA
| | - David R. Scott
- Department Physiology, David Geffen School of Medicine at UCLA,VA GLAHS, Los Angeles, CA,Corresponding author: David R. Scott, Department of Physiology, DGSOM at UCLA, VA GLAHS, Bldg 113, Rm 324, 11301 Wilshire Blvd, Los Angeles, CA 90073, , phone: 310-478-3711 x42046; Fax: 310-312-9478
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31
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Lindemann C, Thomanek N, Kuhlmann K, Meyer HE, Marcus K, Narberhaus F. Next-Generation Trapping of Protease Substrates by Label-Free Proteomics. Methods Mol Biol 2018; 1841:189-206. [PMID: 30259488 DOI: 10.1007/978-1-4939-8695-8_14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
AAA+ proteases (ATPases associated with various cellular activities) shape the cellular protein pool in response to environmental conditions. A prerequisite for understanding the underlying recognition and degradation principles is the identification of as many protease substrates as possible. Most previous studies made use of inactive protease variants to trap substrates, which were identified by 2D-gel based proteomics. Since this method is known for limitations in the identification of low-abundant proteins or proteins with many transmembrane domains, we established a trapping approach that overcomes these limitations. We used a proteolytically inactive FtsH variant (FtsHtrap) of Escherichia coli (E. coli) that is still able to bind and translocate substrates into the proteolytic chamber but no longer able to degrade proteins. Proteins associated with FtsHtrap or FtsHwt (proteolytically active FtsH) were purified, concentrated by an 1D-short gel, and identified by LC-coupled mass spectrometry (LC-MS) followed by label-free quantification. The identification of four known FtsH substrates validated this approach and suggests that it is generally applicable to AAA+ proteases.
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Affiliation(s)
- Claudia Lindemann
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, Bochum, Germany
| | - Nikolas Thomanek
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, Bochum, Germany
| | - Katja Kuhlmann
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, Bochum, Germany
| | - Helmut E Meyer
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, Bochum, Germany
| | - Katrin Marcus
- Medizinisches Proteom-Center, Ruhr-Universität Bochum, Bochum, Germany
| | - Franz Narberhaus
- Lehrstuhl für Biologie der Mikroorganismen, Ruhr-Universität Bochum, Bochum, Germany.
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32
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Miyazaki R, Myougo N, Mori H, Akiyama Y. A photo-cross-linking approach to monitor folding and assembly of newly synthesized proteins in a living cell. J Biol Chem 2017; 293:677-686. [PMID: 29158258 DOI: 10.1074/jbc.m117.817270] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 11/03/2017] [Indexed: 11/06/2022] Open
Abstract
Many proteins form multimeric complexes that play crucial roles in various cellular processes. Studying how proteins are correctly folded and assembled into such complexes in a living cell is important for understanding the physiological roles and the qualitative and quantitative regulation of the complex. However, few methods are suitable for analyzing these rapidly occurring processes. Site-directed in vivo photo-cross-linking is an elegant technique that enables analysis of protein-protein interactions in living cells with high spatial resolution. However, the conventional site-directed in vivo photo-cross-linking method is unsuitable for analyzing dynamic processes. Here, by combining an improved site-directed in vivo photo-cross-linking technique with a pulse-chase approach, we developed a new method that can analyze the folding and assembly of a newly synthesized protein with high spatiotemporal resolution. We demonstrate that this method, named the pulse-chase and in vivo photo-cross-linking experiment (PiXie), enables the kinetic analysis of the formation of an Escherichia coli periplasmic (soluble) protein complex (PhoA). We also used our new technique to investigate assembly/folding processes of two membrane complexes (SecD-SecF in the inner membrane and LptD-LptE in the outer membrane), which provided new insights into the biogenesis of these complexes. Our PiXie method permits analysis of the dynamic behavior of various proteins and enables examination of protein-protein interactions at the level of individual amino acid residues. We anticipate that our new technique will have valuable utility for studies of protein dynamics in many organisms.
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Affiliation(s)
- Ryoji Miyazaki
- From the Institute for Frontier Life and Medical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
| | - Naomi Myougo
- From the Institute for Frontier Life and Medical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
| | - Hiroyuki Mori
- From the Institute for Frontier Life and Medical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
| | - Yoshinori Akiyama
- From the Institute for Frontier Life and Medical Sciences, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan
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33
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Crane JM, Randall LL. The Sec System: Protein Export in Escherichia coli. EcoSal Plus 2017; 7:10.1128/ecosalplus.ESP-0002-2017. [PMID: 29165233 PMCID: PMC5807066 DOI: 10.1128/ecosalplus.esp-0002-2017] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Indexed: 11/20/2022]
Abstract
In Escherichia coli, proteins found in the periplasm or the outer membrane are exported from the cytoplasm by the general secretory, Sec, system before they acquire stably folded structure. This dynamic process involves intricate interactions among cytoplasmic and membrane proteins, both peripheral and integral, as well as lipids. In vivo, both ATP hydrolysis and proton motive force are required. Here, we review the Sec system from the inception of the field through early 2016, including biochemical, genetic, and structural data.
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Affiliation(s)
- Jennine M. Crane
- Department of Biochemistry, University of Missouri, Columbia, Missouri
| | - Linda L. Randall
- Department of Biochemistry, University of Missouri, Columbia, Missouri
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34
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Weir NR, Kamber RA, Martenson JS, Denic V. The AAA protein Msp1 mediates clearance of excess tail-anchored proteins from the peroxisomal membrane. eLife 2017; 6:28507. [PMID: 28906250 PMCID: PMC5633344 DOI: 10.7554/elife.28507] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 09/12/2017] [Indexed: 12/29/2022] Open
Abstract
Msp1 is a conserved AAA ATPase in budding yeast localized to mitochondria where it prevents accumulation of mistargeted tail-anchored (TA) proteins, including the peroxisomal TA protein Pex15. Msp1 also resides on peroxisomes but it remains unknown how native TA proteins on mitochondria and peroxisomes evade Msp1 surveillance. We used live-cell quantitative cell microscopy tools and drug-inducible gene expression to dissect Msp1 function. We found that a small fraction of peroxisomal Pex15, exaggerated by overexpression, is turned over by Msp1. Kinetic measurements guided by theoretical modeling revealed that Pex15 molecules at mitochondria display age-independent Msp1 sensitivity. By contrast, Pex15 molecules at peroxisomes are rapidly converted from an initial Msp1-sensitive to an Msp1-resistant state. Lastly, we show that Pex15 interacts with the peroxisomal membrane protein Pex3, which shields Pex15 from Msp1-dependent turnover. In sum, our work argues that Msp1 selects its substrates on the basis of their solitary membrane existence.
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Affiliation(s)
- Nicholas R Weir
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
| | - Roarke A Kamber
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
| | - James S Martenson
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
| | - Vladimir Denic
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, United States
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35
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Rewiring of the FtsH regulatory network by a single nucleotide change in saeS of Staphylococcus aureus. Sci Rep 2017; 7:8456. [PMID: 28814746 PMCID: PMC5559551 DOI: 10.1038/s41598-017-08774-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 07/18/2017] [Indexed: 11/08/2022] Open
Abstract
In the Gram-positive pathogen Staphylococcus aureus, the membrane-bound ATP-dependent metalloprotease FtsH plays a critical role in resistance to various stressors. However, the molecular mechanism of the FtsH functions is not known. Here, we identified core FtsH target proteins in S. aureus. In the strains Newman and USA300, the abundance of 33 proteins were altered in both strains, of which 11 were identified as core FtsH substrate protein candidates. In the strain Newman and some other S. aureus strains, the sensor histidine kinase SaeS has an L18P (T53C in saeS) substitution, which transformed the protein into an FtsH substrate. Due to the increase of SaeS L18P in the ftsH mutant, Eap, a sae-regulon protein, was also increased in abundance, causing the Newman-specific cell-aggregation phenotype. Regardless of the strain background, however, the ftsH mutants showed lower virulence and survival in a murine infection model. Our study illustrates the elasticity of the bacterial regulatory network, which can be rewired by a single substitution mutation.
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36
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Bittner LM, Arends J, Narberhaus F. When, how and why? Regulated proteolysis by the essential FtsH protease in Escherichia coli. Biol Chem 2017; 398:625-635. [PMID: 28085670 DOI: 10.1515/hsz-2016-0302] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 01/09/2017] [Indexed: 11/15/2022]
Abstract
Cellular proteomes are dynamic and adjusted to permanently changing conditions by ATP-fueled proteolytic machineries. Among the five AAA+ proteases in Escherichia coli FtsH is the only essential and membrane-anchored metalloprotease. FtsH is a homohexamer that uses its ATPase domain to unfold and translocate substrates that are subsequently degraded without the need of ATP in the proteolytic chamber of the protease domain. FtsH eliminates misfolded proteins in the context of general quality control and properly folded proteins for regulatory reasons. Recent trapping approaches have revealed a number of novel FtsH substrates. This review summarizes the substrate diversity of FtsH and presents details on the surprisingly diverse recognition principles of three well-characterized substrates: LpxC, the key enzyme of lipopolysaccharide biosynthesis; RpoH, the alternative heat-shock sigma factor and YfgM, a bifunctional membrane protein implicated in periplasmic chaperone functions and cytoplasmic stress adaptation.
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Affiliation(s)
- Lisa-Marie Bittner
- Microbial Biology, Ruhr University Bochum, Universitätsstr. 150, NDEF 06/783, D-44801 Bochum
| | - Jan Arends
- Microbial Biology, Ruhr University Bochum, Universitätsstr. 150, NDEF 06/783, D-44801 Bochum
| | - Franz Narberhaus
- Microbial Biology, Ruhr University Bochum, Universitätsstr. 150, NDEF 06/783, D-44801 Bochum
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37
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Abstract
All bacteria utilize pathways to export proteins from the cytoplasm to the bacterial cell envelope or extracellular space. Many exported proteins function in essential physiological processes or in virulence. Consequently, the responsible protein export pathways are commonly essential and/or are important for pathogenesis. The general Sec protein export pathway is conserved and essential in all bacteria, and it is responsible for most protein export. The energy for Sec export is provided by the SecA ATPase. Mycobacteria and some Gram-positive bacteria have two SecA paralogs: SecA1 and SecA2. SecA1 is essential and works with the canonical Sec pathway to perform the bulk of protein export. The nonessential SecA2 exports a smaller subset of proteins and is required for the virulence of pathogens such as Mycobacterium tuberculosis. In this article, we review our current understanding of the mechanism of the SecA1 and SecA2 export pathways and discuss some of their better-studied exported substrates. We focus on proteins with established functions in M. tuberculosis pathogenesis and proteins that suggest potential roles for SecA1 and SecA2 in M. tuberculosis dormancy.
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38
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Sachelaru I, Winter L, Knyazev DG, Zimmermann M, Vogt A, Kuttner R, Ollinger N, Siligan C, Pohl P, Koch HG. YidC and SecYEG form a heterotetrameric protein translocation channel. Sci Rep 2017; 7:101. [PMID: 28273911 PMCID: PMC5427846 DOI: 10.1038/s41598-017-00109-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 02/08/2017] [Indexed: 11/26/2022] Open
Abstract
The heterotrimeric SecYEG complex cooperates with YidC to facilitate membrane protein insertion by an unknown mechanism. Here we show that YidC contacts the interior of the SecY channel resulting in a ligand-activated and voltage-dependent complex with distinct ion channel characteristics. The SecYEG pore diameter decreases from 8 Å to only 5 Å for the YidC-SecYEG pore, indicating a reduction in channel cross-section by YidC intercalation. In the presence of a substrate, YidC relocates to the rim of the pore as indicated by increased pore diameter and loss of YidC crosslinks to the channel interior. Changing the surface charge of the pore by incorporating YidC into the channel wall increases the anion selectivity, and the accompanying change in wall hydrophobicity is liable to alter the partition of helices from the pore into the membrane. This could explain how the exit of transmembrane domains from the SecY channel is facilitated by YidC.
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Affiliation(s)
- Ilie Sachelaru
- grid.5963.9Institut für Biochemie und Molekularbiologie, ZBMZ, Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Stefan Meier Str. 17, Freiburg, 79104 Germany ,grid.5963.9Fakultät für Biologie, Albert-Ludwigs-Universität Freiburg, Stefan Meier Str. 17, 79104 Freiburg, Germany
| | - Lukas Winter
- 0000 0001 1941 5140grid.9970.7Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, A-4020 Linz, Austria
| | - Denis G. Knyazev
- 0000 0001 1941 5140grid.9970.7Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, A-4020 Linz, Austria
| | - Mirjam Zimmermann
- 0000 0001 1941 5140grid.9970.7Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, A-4020 Linz, Austria
| | - Andreas Vogt
- grid.5963.9Institut für Biochemie und Molekularbiologie, ZBMZ, Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Stefan Meier Str. 17, Freiburg, 79104 Germany ,grid.5963.9Fakultät für Biologie, Albert-Ludwigs-Universität Freiburg, Stefan Meier Str. 17, 79104 Freiburg, Germany ,grid.5963.9Spemann-Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Roland Kuttner
- 0000 0001 1941 5140grid.9970.7Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, A-4020 Linz, Austria
| | - Nicole Ollinger
- 0000 0001 1941 5140grid.9970.7Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, A-4020 Linz, Austria
| | - Christine Siligan
- 0000 0001 1941 5140grid.9970.7Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, A-4020 Linz, Austria
| | - Peter Pohl
- Institute of Biophysics, Johannes Kepler University Linz, Gruberstrasse 40, A-4020, Linz, Austria.
| | - Hans-Georg Koch
- Institut für Biochemie und Molekularbiologie, ZBMZ, Faculty of Medicine, Albert-Ludwigs-Universität Freiburg, Stefan Meier Str. 17, Freiburg, 79104, Germany. .,Spemann-Graduate School of Biology and Medicine (SGBM), Albert-Ludwigs-Universität Freiburg, 79104, Freiburg, Germany.
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Arends J, Thomanek N, Kuhlmann K, Marcus K, Narberhaus F. In vivo trapping of FtsH substrates by label-free quantitative proteomics. Proteomics 2016; 16:3161-3172. [DOI: 10.1002/pmic.201600316] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 09/09/2016] [Accepted: 10/19/2016] [Indexed: 11/09/2022]
Affiliation(s)
- Jan Arends
- Ruhr-Universität Bochum; Lehrstuhl Biologie der Mikroorganismen; Bochum Germany
| | - Nikolas Thomanek
- Ruhr-Universität Bochum; Medizinisches Proteom-Center; Bochum Germany
| | - Katja Kuhlmann
- Ruhr-Universität Bochum; Medizinisches Proteom-Center; Bochum Germany
| | - Katrin Marcus
- Ruhr-Universität Bochum; Medizinisches Proteom-Center; Bochum Germany
| | - Franz Narberhaus
- Ruhr-Universität Bochum; Lehrstuhl Biologie der Mikroorganismen; Bochum Germany
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Liu X, Zhang W, Zhao Z, Dai X, Yang Y, Bai Z. Protein secretion in Corynebacterium glutamicum. Crit Rev Biotechnol 2016; 37:541-551. [PMID: 27737570 DOI: 10.1080/07388551.2016.1206059] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Corynebacterium glutamicum, a Gram-positive bacterium, has been widely used for the industrial production of amino acids, such as glutamate and lysine, for decades. Due to several characteristics - its ability to secrete properly folded and functional target proteins into culture broth, its low levels of endogenous extracellular proteins and its lack of detectable extracellular hydrolytic enzyme activity - C. glutamicum is also a very favorable host cell for the secretory production of heterologous proteins, important enzymes, and pharmaceutical proteins. The target proteins are secreted into the culture medium, which has attractive advantages over the manufacturing process for inclusion of body expression - the simplified downstream purification process. The secretory process of proteins is complicated and energy consuming. There are two major secretory pathways in C. glutamicum, the Sec pathway and the Tat pathway, both have specific signal peptides that mediate the secretion of the target proteins. In the present review, we critically discuss recent progress in the secretory production of heterologous proteins and examine in depth the mechanisms of the protein translocation process in C. glutamicum. Some successful case studies of actual applications of this secretory expression host are also evaluated. Finally, the existing issues and solutions in using C. glutamicum as a host of secretory proteins are specifically addressed.
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Affiliation(s)
- Xiuxia Liu
- a National Engineering Laboratory for Cereal Fermentation Technology , Jiangnan University , Wuxi , China.,b The Key Laboratory of Industrial Biotechnology, Ministry of Education , School of Biotechnology, Jiangnan University , Wuxi , China
| | - Wei Zhang
- a National Engineering Laboratory for Cereal Fermentation Technology , Jiangnan University , Wuxi , China.,b The Key Laboratory of Industrial Biotechnology, Ministry of Education , School of Biotechnology, Jiangnan University , Wuxi , China
| | - Zihao Zhao
- a National Engineering Laboratory for Cereal Fermentation Technology , Jiangnan University , Wuxi , China.,b The Key Laboratory of Industrial Biotechnology, Ministry of Education , School of Biotechnology, Jiangnan University , Wuxi , China
| | - Xiaofeng Dai
- a National Engineering Laboratory for Cereal Fermentation Technology , Jiangnan University , Wuxi , China.,b The Key Laboratory of Industrial Biotechnology, Ministry of Education , School of Biotechnology, Jiangnan University , Wuxi , China
| | - Yankun Yang
- a National Engineering Laboratory for Cereal Fermentation Technology , Jiangnan University , Wuxi , China.,b The Key Laboratory of Industrial Biotechnology, Ministry of Education , School of Biotechnology, Jiangnan University , Wuxi , China
| | - Zhonghu Bai
- a National Engineering Laboratory for Cereal Fermentation Technology , Jiangnan University , Wuxi , China.,b The Key Laboratory of Industrial Biotechnology, Ministry of Education , School of Biotechnology, Jiangnan University , Wuxi , China
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Hari SB, Sauer RT. The AAA+ FtsH Protease Degrades an ssrA-Tagged Model Protein in the Inner Membrane of Escherichia coli. Biochemistry 2016; 55:5649-5652. [PMID: 27677373 DOI: 10.1021/acs.biochem.6b00920] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In eubacteria, the tmRNA system frees ribosomes that stall during protein synthesis and adds an ssrA tag to the incompletely translated polypeptide to target it for degradation. The AAA+ ClpXP protease degrades most ssrA-tagged proteins in the Escherichia coli cytoplasm and was recently shown to degrade an ssrA-tagged protein in the inner membrane. However, we find that tmRNA-mediated tagging of E. coli ProW1-182, a different inner-membrane protein, results in degradation by the membrane-tethered AAA+ FtsH protease. ClpXP played no role in the degradation of ProW1-182 in vivo. These studies suggest that a complex distribution of proteolytic labor maintains protein quality control in the inner membrane.
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Affiliation(s)
- Sanjay B Hari
- Department of Biology, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
| | - Robert T Sauer
- Department of Biology, Massachusetts Institute of Technology , Cambridge, Massachusetts 02139, United States
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Abstract
For more than four decades now, I have been studying how genetic information is transformed into protein-based cellular functions. This has included investigations into the mechanisms supporting cellular localization of proteins, disulfide bond formation, quality control of membranes, and translation. I tried to extract new principles and concepts that are universal among living organisms from our observations of Escherichia coli. While I wanted to distill complex phenomena into basic principles, I also tried not to overlook any serendipitous observations. In the first part of this article, I describe personal experiences during my studies of the Sec pathway, which have centered on the SecY translocon. In the second part, I summarize my views of the recent revival of translation studies, which has given rise to the concept that nonuniform polypeptide chain elongation is relevant for the subsequent fates of newly synthesized proteins. Our studies of a class of regulatory nascent polypeptides advance this concept by showing that the dynamic behaviors of the extraribosomal part of the nascent chain affect the ongoing translation process. Vibrant and regulated molecular interactions involving the ribosome, mRNA, and nascent polypeptidyl-tRNA are based, at least partly, on their autonomously interacting properties.
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Affiliation(s)
- Koreaki Ito
- Faculty of Life Sciences, Kyoto Sangyo University, Kyoto 603-8555, Japan;
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Qi Y, Zhao J, An R, Zhang J, Liang S, Shao J, Liu X, An L, Yu F. Mutations in circularly permuted GTPase family genes AtNOA1/RIF1/SVR10 and BPG2 suppress var2-mediated leaf variegation in Arabidopsis thaliana. PHOTOSYNTHESIS RESEARCH 2016; 127:355-67. [PMID: 26435530 DOI: 10.1007/s11120-015-0195-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Accepted: 09/24/2015] [Indexed: 05/18/2023]
Abstract
Leaf variegation mutants constitute a unique group of chloroplast development mutants and are ideal genetic materials to dissect the regulation of chloroplast development. We have utilized the Arabidopsis yellow variegated (var2) mutant and genetic suppressor analysis to probe the mechanisms of chloroplast development. Here we report the isolation of a new var2 suppressor locus SUPPRESSOR OF VARIEGATION (SVR10). Genetic mapping and molecular complementation indicated that SVR10 encodes a circularly permuted GTPase that has been reported as Arabidopsis thaliana NITRIC OXIDE ASSOCIATED 1 (AtNOA1) and RESISTANT TO INHIBITION BY FOSMIDOMYCIN 1 (RIF1). Biochemical evidence showed that SVR10/AtNOA1/RIF1 likely localizes to the chloroplast stroma. We further demonstrate that the mutant of a close homologue of SVR10/AtNOA1/RIF1, BRASSINAZOLE INSENSITIVE PALE GREEN 2 (BPG2), can also suppress var2 leaf variegation. Mutants of SVR10 and BPG2 are impaired in photosynthesis and the accumulation of chloroplast proteins. Interestingly, two-dimensional blue native gel analysis showed that mutants of SVR10 and BPG2 display defects in the assembly of thylakoid membrane complexes including reduced levels of major photosynthetic complexes and the abnormal accumulation of a chlorophyll-protein supercomplex containing photosystem I. Taken together, our findings suggest that SVR10 and BPG2 are functionally related with VAR2, likely through their potential roles in regulating chloroplast protein homeostasis, and both SVR10 and BPG2 are required for efficient thylakoid protein complex assembly and photosynthesis.
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Affiliation(s)
- Yafei Qi
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China
| | - Jun Zhao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China
| | - Rui An
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China
| | - Juan Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China
| | - Shuang Liang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China
| | - Jingxia Shao
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China
| | - Xiayan Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China
| | - Lijun An
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China
| | - Fei Yu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Life Sciences, Northwest A&F University, Yangling, 712100, Shaanxi, People's Republic of China.
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Nascent chain-monitored remodeling of the Sec machinery for salinity adaptation of marine bacteria. Proc Natl Acad Sci U S A 2015; 112:E5513-22. [PMID: 26392525 DOI: 10.1073/pnas.1513001112] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
SecDF interacts with the SecYEG translocon in bacteria and enhances protein export in a proton-motive-force-dependent manner. Vibrio alginolyticus, a marine-estuarine bacterium, contains two SecDF paralogs, V.SecDF1 and V.SecDF2. Here, we show that the export-enhancing function of V.SecDF1 requires Na+ instead of H+, whereas V.SecDF2 is Na+-independent, presumably requiring H+. In accord with the cation-preference difference, V.SecDF2 was only expressed under limited Na+ concentrations whereas V.SecDF1 was constitutive. However, it is not the decreased concentration of Na+ per se that the bacterium senses to up-regulate the V.SecDF2 expression, because marked up-regulation of the V.SecDF2 synthesis was observed irrespective of Na+ concentrations under certain genetic/physiological conditions: (i) when the secDF1VA gene was deleted and (ii) whenever the Sec export machinery was inhibited. VemP (Vibrio export monitoring polypeptide), a secretory polypeptide encoded by the upstream ORF of secDF2VA, plays the primary role in this regulation by undergoing regulated translational elongation arrest, which leads to unfolding of the Shine-Dalgarno sequence for translation of secDF2VA. Genetic analysis of V. alginolyticus established that the VemP-mediated regulation of SecDF2 is essential for the survival of this marine bacterium in low-salinity environments. These results reveal that a class of marine bacteria exploits nascent-chain ribosome interactions to optimize their protein export pathways to propagate efficiently under different ionic environments that they face in their life cycles.
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Cymer F, von Heijne G, White SH. Mechanisms of integral membrane protein insertion and folding. J Mol Biol 2014; 427:999-1022. [PMID: 25277655 DOI: 10.1016/j.jmb.2014.09.014] [Citation(s) in RCA: 243] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/13/2014] [Accepted: 09/22/2014] [Indexed: 11/30/2022]
Abstract
The biogenesis, folding, and structure of α-helical membrane proteins (MPs) are important to understand because they underlie virtually all physiological processes in cells including key metabolic pathways, such as the respiratory chain and the photosystems, as well as the transport of solutes and signals across membranes. Nearly all MPs require translocons--often referred to as protein-conducting channels--for proper insertion into their target membrane. Remarkable progress toward understanding the structure and functioning of translocons has been made during the past decade. Here, we review and assess this progress critically. All available evidence indicates that MPs are equilibrium structures that achieve their final structural states by folding along thermodynamically controlled pathways. The main challenge for cells is the targeting and membrane insertion of highly hydrophobic amino acid sequences. Targeting and insertion are managed in cells principally by interactions between ribosomes and membrane-embedded translocons. Our review examines the biophysical and biological boundaries of MP insertion and the folding of polytopic MPs in vivo. A theme of the review is the under-appreciated role of basic thermodynamic principles in MP folding and assembly. Thermodynamics not only dictates the final folded structure but also is the driving force for the evolution of the ribosome-translocon system of assembly. We conclude the review with a perspective suggesting a new view of translocon-guided MP insertion.
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Affiliation(s)
- Florian Cymer
- Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm
| | - Gunnar von Heijne
- Center for Biomembrane Research, Department of Biochemistry and Biophysics, Stockholm University, SE-106 91 Stockholm.,Science for Life Laboratory Stockholm University, Box 1031, SE-171 21 Solna, Sweden
| | - Stephen H White
- Department of Physiology and Biophysics and the Center for Biomembrane Systems University of California, Irvine Irvine, CA 92697
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Streptococcus pyogenes polymyxin B-resistant mutants display enhanced ExPortal integrity. J Bacteriol 2014; 196:2563-77. [PMID: 24794568 DOI: 10.1128/jb.01596-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The ExPortal protein secretion organelle in Streptococcus pyogenes is an anionic phospholipid-containing membrane microdomain enriched in Sec translocons and postsecretion protein biogenesis factors. Polymyxin B binds to and disrupts ExPortal integrity, resulting in defective secretion of several toxins. To gain insight into factors that influence ExPortal organization, a genetic screen was conducted to select for spontaneous polymyxin B-resistant mutants displaying enhanced ExPortal integrity. Whole-genome resequencing of 25 resistant mutants revealed from one to four mutations per mutant genome clustered primarily within a core set of 10 gene groups. Construction of mutants with individual deletions or insertions demonstrated that 7 core genes confer resistance and enhanced ExPortal integrity through loss of function, while 3 were likely due to gain of function and/or combinatorial effects. Core resistance genes include a transcriptional regulator of lipid biosynthesis, several genes involved in nutrient acquisition, and a variety of genes involved in stress responses. Two members of the latter class also function as novel regulators of the secreted SpeB cysteine protease. Analysis of the most frequently isolated mutation, a single nucleotide deletion in a track of 9 consecutive adenine residues in pstS, encoding a component of a high-affinity Pi transporter, suggests that this sequence functions as a molecular switch to facilitate stress adaptation. Together, these data suggest the existence of a membrane stress response that promotes enhanced ExPortal integrity and resistance to cationic antimicrobial peptides.
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Denks K, Vogt A, Sachelaru I, Petriman NA, Kudva R, Koch HG. The Sec translocon mediated protein transport in prokaryotes and eukaryotes. Mol Membr Biol 2014; 31:58-84. [DOI: 10.3109/09687688.2014.907455] [Citation(s) in RCA: 123] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Nakamura Y, Andrés F, Kanehara K, Liu YC, Dörmann P, Coupland G. Arabidopsis florigen FT binds to diurnally oscillating phospholipids that accelerate flowering. Nat Commun 2014; 5:3553. [PMID: 24698997 PMCID: PMC3988816 DOI: 10.1038/ncomms4553] [Citation(s) in RCA: 117] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Accepted: 03/05/2014] [Indexed: 01/21/2023] Open
Abstract
Arabidopsis FT protein is a component of florigen, which transmits photoperiodic flowering signals from leaf companion cells to the shoot apex. Here, we show that FT specifically binds phosphatidylcholine (PC) in vitro. A transgenic approach to increase PC levels in vivo in the shoot meristem accelerates flowering whereas reduced PC levels delay flowering, demonstrating that PC levels are correlated with flowering time. The early flowering is related to FT activity, because expression of FT-effector genes is increased in these plants. Simultaneous increase of FT and PC in the shoot apical meristem further stimulates flowering, whereas a loss of FT function leads to an attenuation of the effect of increased PC. Specific molecular species of PC oscillate diurnally, and night-dominant species are not the preferred ligands of FT. Elevating night-dominant species during the day delays flowering. We suggest that FT binds to diurnally changing molecular species of PC to promote flowering. Daytime flowering in Arabidopsis is stimulated by the secreted protein FT. Nakamura et al. show that FT binds the lipid phosphatidylcholine (PC) in vitro, and that in plants, different PC species predominate during day and night, with daytime species stimulating flowering in a manner that is partially dependent on FT.
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Affiliation(s)
- Yuki Nakamura
- 1] Institute of Plant and Microbial Biology, Academia Sinica, 128 Section 2 Academia Road, Nankang, Taipei 11529, Taiwan [2] Max-Planck-Institute for Plant Breeding Research, Carl-von-Linne-Weg 10, Cologne 50829, Germany [3] Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Karlrobert-Kreiten-Strasse 13, Bonn 53115, Germany [4] Japan Science and Technology Agency, PRESTO, 4-8-1 Honcho, Kawaguchi, Saitama 332-0012, Japan
| | - Fernando Andrés
- Max-Planck-Institute for Plant Breeding Research, Carl-von-Linne-Weg 10, Cologne 50829, Germany
| | - Kazue Kanehara
- Institute of Plant and Microbial Biology, Academia Sinica, 128 Section 2 Academia Road, Nankang, Taipei 11529, Taiwan
| | - Yu-chi Liu
- Institute of Plant and Microbial Biology, Academia Sinica, 128 Section 2 Academia Road, Nankang, Taipei 11529, Taiwan
| | - Peter Dörmann
- Institute of Molecular Physiology and Biotechnology of Plants, University of Bonn, Karlrobert-Kreiten-Strasse 13, Bonn 53115, Germany
| | - George Coupland
- Max-Planck-Institute for Plant Breeding Research, Carl-von-Linne-Weg 10, Cologne 50829, Germany
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Identification of YidC residues that define interactions with the Sec Apparatus. J Bacteriol 2013; 196:367-77. [PMID: 24187090 DOI: 10.1128/jb.01095-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In bacteria, a subset of membrane proteins insert into the membrane via the Sec apparatus with the assistance of the widely conserved essential membrane protein insertase YidC. After threading into the SecYEG translocon, transmembrane segments of nascent proteins are thought to exit the translocon via a lateral gate in SecY, where YidC facilitates their transfer into the lipid bilayer. Interactions between YidC and components of the Sec apparatus are critical to its function. The first periplasmic loop of YidC interacts directly with SecF. We sought to identify the regions or residues of YidC that interact with SecY or with additional components of the Sec apparatus other than SecDF. Using a synthetic lethal screen, we identified residues of YidC that, when mutated, led to dependence on SecDF for viability. Each residue identified is highly conserved among YidC homologs; most lie within transmembrane domains. Overexpression of SecY in the presence of two YidC mutants partially rescued viability in the absence of SecDF, suggesting that the corresponding wild-type YidC residues (G355 and M471) participate in interactions, direct or indirect, with SecY. Staphylococcus aureus YidC complemented depletion of YidC, but not of SecDF, in Escherichia coli. G355 of E. coli YidC is invariant in S. aureus YidC, suggesting that this highly conserved glycine serves a conserved function in interactions with SecY. This study demonstrates that transmembrane residues are critical in YidC interactions with the Sec apparatus and provides guidance on YidC residues of interest for future structure-function analyses.
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