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Rozov SM, Deineko EV. Increasing the Efficiency of the Accumulation of Recombinant Proteins in Plant Cells: The Role of Transport Signal Peptides. PLANTS (BASEL, SWITZERLAND) 2022; 11:2561. [PMID: 36235427 PMCID: PMC9572730 DOI: 10.3390/plants11192561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 09/23/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
The problem with increasing the yield of recombinant proteins is resolvable using different approaches, including the transport of a target protein to cell compartments with a low protease activity. In the cell, protein targeting involves short-signal peptide sequences recognized by intracellular protein transport systems. The main systems of the protein transport across membranes of the endoplasmic reticulum and endosymbiotic organelles are reviewed here, as are the major types and structure of the signal sequences targeting proteins to the endoplasmic reticulum and its derivatives, to plastids, and to mitochondria. The role of protein targeting to certain cell organelles depending on specific features of recombinant proteins and the effect of this targeting on the protein yield are discussed, in addition to the main directions of the search for signal sequences based on their primary structure. This knowledge makes it possible not only to predict a protein localization in the cell but also to reveal the most efficient sequences with potential biotechnological utility.
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Hao B, Liu L, Liu N, Sun L, Fan F, Huang J. The Bombyx mori Nucleopolyhedrovirus GP64 Retains the Transmembrane Helix of Signal Peptide to Contribute to Secretion across the Cytomembrane. Microbiol Spectr 2022; 10:e0191322. [PMID: 35938817 PMCID: PMC9430547 DOI: 10.1128/spectrum.01913-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2022] [Accepted: 07/14/2022] [Indexed: 11/20/2022] Open
Abstract
Bombyx mori nucleopolyhedrovirus (BmNPV) is the primary pathogen of silkworms that causes severe economic losses in sericulture. GP64 is the key membrane fusion protein that mediates budded virus (BV) fusion with the host cell membrane. Previously, we found that the n-region of the GP64 signal peptide (SP) is required for protein secretion and viral pathogenicity; however, our understanding of BmNPV GP64 remains limited. Here, we first reported that BmNPV GP64 retained its SP in the mature protein and virion in only host cells but did not retain in nonhost cells. Uncleaved SP mediates protein targeting to the cytomembrane or secretion in Bombyx mori cells. The exitance of the n-region extended the transmembrane helix length, which resulted in the cleavage site to be located in the helix structure and thus blocked cleavage from signal peptidase (SPase). Without the n-region, the protein fails to be transported to the cytomembrane, but this failure can be rescued by the cleavage site mutation of SP. Helix-breaking mutations in SP abolished protein targeting to the cytomembrane and secretion. Our results revealed a previously unrecognized mechanism by which SP of membrane fusion not only determines protein localization but also determines viral pathogenicity, which highlights the escape mechanism of SP from the cleavage by SPase. IMPORTANCE BmNPV is the primary pathogen of silkworms, which causes severe economic losses in sericulture. BmNPV and Autographa californica multiple nucleopolyhedrovirus (AcMNPV) are closely related group I alphabaculoviruses, but they exhibit nonoverlapping host specificity. Recent studies suppose that GP64 is a determinant of host range, while knowledge remains limited. In this study, we revealed that BmNPV GP64 retained its SP in host cells but not in nonhost cells, and the SP retention is required for GP64 secretion across the cytomembrane. This is the first report that a type I membrane fusion protein retained its SP in mature proteins and virions. Our results unveil the mechanism by which SP GP64 escapes cleavage and the role of SP in protein targeting. This study will help elucidate an important mechanistic understanding of BmNPV infection and host range specificity.
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Affiliation(s)
- Bifang Hao
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, People’s Republic of China
- Key Laboratory of Genetic Improvement of Sericulture in the Ministry of Agriculture, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang, Jiangsu, People’s Republic of China
| | - Lin Liu
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, People’s Republic of China
| | - Na Liu
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, People’s Republic of China
| | - Luping Sun
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, People’s Republic of China
| | - Fengxiu Fan
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, People’s Republic of China
| | - Jinshan Huang
- Jiangsu Key Laboratory of Sericultural Biology and Biotechnology, School of Biotechnology, Jiangsu University of Science and Technology, Zhenjiang, Jiangsu, People’s Republic of China
- Key Laboratory of Genetic Improvement of Sericulture in the Ministry of Agriculture, Sericultural Research Institute, Chinese Academy of Agricultural Science, Zhenjiang, Jiangsu, People’s Republic of China
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3
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Das P, Xu WK, Gautam AKS, Lozano MM, Dudley JP. A Retrotranslocation Assay That Predicts Defective VCP/p97-Mediated Trafficking of a Retroviral Signal Peptide. mBio 2022; 13:e0295321. [PMID: 35089078 PMCID: PMC8725593 DOI: 10.1128/mbio.02953-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 11/18/2021] [Indexed: 12/12/2022] Open
Abstract
Studies of viral replication have provided critical insights into host processes, including protein trafficking and turnover. Mouse mammary tumor virus (MMTV) is a betaretrovirus that encodes a functional 98-amino-acid signal peptide (SP). MMTV SP is generated from both Rem and envelope precursor proteins by signal peptidase cleavage in the endoplasmic reticulum (ER) membrane. We previously showed that SP functions as a human immunodeficiency virus type 1 (HIV-1) Rev-like protein that is dependent on the AAA ATPase valosin-containing protein (VCP)/p97 to subvert ER-associated degradation (ERAD). SP contains a nuclear localization sequence (NLS)/nucleolar localization sequence (NoLS) within the N-terminal 45 amino acids. To directly determine the SP regions needed for membrane extraction and trafficking, we developed a quantitative retrotranslocation assay with biotin acceptor peptide (BAP)-tagged SP proteins. Use of alanine substitution mutants of BAP-tagged MMTV SP in retrotranslocation assays revealed that mutation of amino acids 57 and 58 (M57-58) interfered with ER membrane extraction, whereas adjacent mutations did not. The M57-58 mutant also showed reduced interaction with VCP/p97 in coimmunoprecipitation experiments. Using transfection and reporter assays to measure activity of BAP-tagged proteins, both M57-58 and an adjacent mutant (M59-61) were functionally defective compared to wild-type SP. Confocal microscopy revealed defects in SP nuclear trafficking and abnormal localization of both M57-58 and M59-61. Furthermore, purified glutathione S-transferase (GST)-tagged M57-58 and M59-61 demonstrated reduced ability to oligomerize compared to tagged wild-type SP. These experiments suggest that SP amino acids 57 and 58 are critical for VCP/p97 interaction and retrotranslocation, whereas residues 57 to 61 are critical for oligomerization and nuclear trafficking independent of the NLS/NoLS. Our results emphasize the complex host interactions with long signal peptides. IMPORTANCE Endoplasmic reticulum-associated degradation (ERAD) is a form of cellular protein quality control that is manipulated by viruses, including the betaretrovirus, mouse mammary tumor virus (MMTV). MMTV-encoded signal peptide (SP) has been shown to interact with an essential ERAD factor, VCP/p97 ATPase, to mediate its extraction from the ER membrane, also known as retrotranslocation, for RNA binding and nuclear function. In this paper, we developed a quantitative retrotranslocation assay that identified an SP substitution mutant, which is defective for VCP interaction as well as nuclear trafficking, oligomer formation, and function. An adjacent SP mutant was competent for retrotranslocation and VCP interaction but shared the other defects. Our results revealed the requirement for VCP during SP trafficking and the complex cellular pathways used by long signal peptides.
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Affiliation(s)
- Poulami Das
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
- LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, Texas, USA
| | - Wendy Kaichun Xu
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
- LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, Texas, USA
| | - Amit Kumar Singh Gautam
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
- LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, Texas, USA
| | - Mary M. Lozano
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
- LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, Texas, USA
| | - Jaquelin P. Dudley
- Department of Molecular Biosciences, The University of Texas at Austin, Austin, Texas, USA
- LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, Texas, USA
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Bhadra P, Helms V. Molecular Modeling of Signal Peptide Recognition by Eukaryotic Sec Complexes. Int J Mol Sci 2021; 22:10705. [PMID: 34639046 PMCID: PMC8509349 DOI: 10.3390/ijms221910705] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 09/17/2021] [Accepted: 09/27/2021] [Indexed: 12/23/2022] Open
Abstract
Here, we review recent molecular modelling and simulation studies of the Sec translocon, the primary component/channel of protein translocation into the endoplasmic reticulum (ER) and bacterial periplasm, respectively. Our focus is placed on the eukaryotic Sec61, but we also mention modelling studies on prokaryotic SecY since both systems operate in related ways. Cryo-EM structures are now available for different conformational states of the Sec61 complex, ranging from the idle or closed state over an inhibited state with the inhibitor mycolactone bound near the lateral gate, up to a translocating state with bound substrate peptide in the translocation pore. For all these states, computational studies have addressed the conformational dynamics of the translocon with respect to the pore ring, the plug region, and the lateral gate. Also, molecular simulations are addressing mechanistic issues of insertion into the ER membrane vs. translocation into the ER, how signal-peptides are recognised at all in the translocation pore, and how accessory proteins affect the Sec61 conformation in the co- and post-translational pathways.
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Affiliation(s)
| | - Volkhard Helms
- Center for Bioinformatics, Saarland Informatics Campus, Saarland University, Postfach 15 11 50, 66041 Saarbruecken, Germany;
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HIV-1 Envelope Glycosylation and the Signal Peptide. Vaccines (Basel) 2021; 9:vaccines9020176. [PMID: 33669676 PMCID: PMC7922494 DOI: 10.3390/vaccines9020176] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Revised: 02/07/2021] [Accepted: 02/16/2021] [Indexed: 12/25/2022] Open
Abstract
The RV144 trial represents the only vaccine trial to demonstrate any protective effect against HIV-1 infection. While the reason(s) for this protection are still being evaluated, it serves as justification for widespread efforts aimed at developing new, more effective HIV-1 vaccines. Advances in our knowledge of HIV-1 immunogens and host antibody responses to these immunogens are crucial to informing vaccine design. While the envelope (Env) protein is the only viral protein present on the surface of virions, it exists in a complex trimeric conformation and is decorated with an array of variable N-linked glycans, making it an important but difficult target for vaccine design. Thus far, efforts to elicit a protective humoral immune response using structural mimics of native Env trimers have been unsuccessful. Notably, the aforementioned N-linked glycans serve as a component of many of the epitopes crucial for the induction of potentially protective broadly neutralizing antibodies (bnAbs). Thus, a greater understanding of Env structural determinants, most critically Env glycosylation, will no doubt be of importance in generating effective immunogens. Recent studies have identified the HIV-1 Env signal peptide (SP) as an important contributor to Env glycosylation. Further investigation into the mechanisms by which the SP directs glycosylation will be important, both in the context of understanding HIV-1 biology and in order to inform HIV-1 vaccine design.
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Zhang WX, Pan X, Shen HB. Signal-3L 3.0: Improving Signal Peptide Prediction through Combining Attention Deep Learning with Window-Based Scoring. J Chem Inf Model 2020; 60:3679-3686. [PMID: 32501689 DOI: 10.1021/acs.jcim.0c00401] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Signal peptides play an important role in guiding and transferring transmembrane proteins and secreted proteins. In recent years, with the explosive growth of protein sequences, computationally predicting signal peptides and their cleavage sites from protein sequences is highly desired. In this work, we present an improved approach, Signal-3L 3.0, for signal peptide recognition and cleavage-site prediction using a 3-layer hybrid method of integrating deep learning algorithms and window-based scoring. There are three main components in the Signal-3L 3.0 prediction engine: (1) a deep bidirectional long short-term memory (Bi-LSTM) network with a soft self-attention learns abstract features from sequences to determine whether a query protein contains a signal peptide; (2) the statistics propensity window-based cleavage site screening method is applied to generate the set of candidate cleavage sites; (3) the prediction of a conditional random field with a hybrid convolutional neural network (CNN) and Bi-LSTM is fused with the window-based score for identifying the final unique cleavage site. Experimental results on the benchmark datasets show that the new deep learning-driven Signal-3L 3.0 yields promising performance. The online server of Signal-3L 3.0 is available at http://www.csbio.sjtu.edu.cn/bioinf/Signal-3L/.
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Affiliation(s)
- Wei-Xun Zhang
- Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai Jiao Tong University, and Institute of Image Processing and Pattern Recognition, Shanghai 200240, China
| | - Xiaoyong Pan
- Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai Jiao Tong University, and Institute of Image Processing and Pattern Recognition, Shanghai 200240, China
| | - Hong-Bin Shen
- Key Laboratory of System Control and Information Processing, Ministry of Education of China, Shanghai Jiao Tong University, and Institute of Image Processing and Pattern Recognition, Shanghai 200240, China
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7
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Owji H, Hemmati S. A comprehensive in silico characterization of bacterial signal peptides for the excretory production of Anabaena variabilis phenylalanine ammonia lyase in Escherichia coli. 3 Biotech 2018; 8:488. [PMID: 30498661 DOI: 10.1007/s13205-018-1517-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Accepted: 11/13/2018] [Indexed: 12/30/2022] Open
Abstract
Anabaena variabilis double mutant (C503S/C565S) phenylalanine ammonia-lyase (PAL) is an appealing enzyme in the enzyme-replacement therapy of phenylketonuria. Yet abundant production of this enzyme has been of concern for industrial production. In this study, we have characterized 1175 bacterial signal peptides (SPs) and identified the most efficient ones for the excretory production of mutant AvPAL. Analysis by SignalP 4.1 revealed that more than 61% of SPs had a D-score greater than 0.7, denoting to be highly efficient. The optimum length of a bacterial SP was 25-30. The preferable net positive charge and the second residue of N-region were + 2 and Lys/Arg, respectively. Highly efficient SPs possessed 3-5 Leus in their H-region and A/L/VXA-FF cleavage site. Highly efficient SPs were from Escherichia coli, corroborating the necessity of an agreement between SPs and the host. Physiochemical characterization of mutant AvPAL conjugates via ProtParam and PROSOII, revealed that ~ 99.5% of proteins would not be entraped in inclusion bodies. Secretory pathways were identified by EffectiveDB and more than 98% of SPs were cleavable. Chimeras were modeled using the I-TASSER program, being evaluated by the Ramachandran plots. The mRNA secondary structure of mutant AvPAL upon linkage to SPs was assessed using the mfold program. It was shown that the linkage of a SP does not affect mutant AvPAL's stability at the protein or mRNA level. AllergenFP tool demonstrated that chimeras were not allergen. SPs, including FMF4_ECOLX, E2BB_ECOLX, and LPTA_ECOLI exhibited the highest propensity for secretion and appropriate features in all analyses.
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Affiliation(s)
- Hajar Owji
- 1Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
- 2Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Shiva Hemmati
- 1Department of Pharmaceutical Biotechnology, School of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran
- 2Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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8
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A comprehensive review of signal peptides: Structure, roles, and applications. Eur J Cell Biol 2018; 97:422-441. [DOI: 10.1016/j.ejcb.2018.06.003] [Citation(s) in RCA: 90] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Revised: 06/18/2018] [Accepted: 06/18/2018] [Indexed: 01/06/2023] Open
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9
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Structural determinants of specificity and regulation of activity in the allosteric loop network of human KLK8/neuropsin. Sci Rep 2018; 8:10705. [PMID: 30013126 PMCID: PMC6048020 DOI: 10.1038/s41598-018-29058-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 06/27/2018] [Indexed: 11/12/2022] Open
Abstract
Human KLK8/neuropsin, a kallikrein-related serine peptidase, is mostly expressed in skin and the hippocampus regions of the brain, where it regulates memory formation by synaptic remodeling. Substrate profiles of recombinant KLK8 were analyzed with positional scanning using fluorogenic tetrapeptides and the proteomic PICS approach, which revealed the prime side specificity. Enzyme kinetics with optimized substrates showed stimulation by Ca2+ and inhibition by Zn2+, which are physiological regulators. Crystal structures of KLK8 with a ligand-free active site and with the inhibitor leupeptin explain the subsite specificity and display Ca2+ bound to the 75-loop. The variants D70K and H99A confirmed the antagonistic role of the cation binding sites. Molecular docking and dynamics calculations provided insights in substrate binding and the dual regulation of activity by Ca2+ and Zn2+, which are important in neuron and skin physiology. Both cations participate in the allosteric surface loop network present in related serine proteases. A comparison of the positional scanning data with substrates from brain suggests an adaptive recognition by KLK8, based on the tertiary structures of its targets. These combined findings provide a comprehensive picture of the molecular mechanisms underlying the enzyme activity of KLK8.
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Wang S, Wang D, Li J, Huang T, Cai YD. Identification and analysis of the cleavage site in a signal peptide using SMOTE, dagging, and feature selection methods. Mol Omics 2018; 14:64-73. [DOI: 10.1039/c7mo00030h] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Several machine learning algorithms were adopted to investigate cleavage sites in a signal peptide. An optimal dagging based classifier was constructed and 870 important features were deemed to be important for this classifier.
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Affiliation(s)
- ShaoPeng Wang
- School of Life Sciences
- Shanghai University
- Shanghai 200444
- People's Republic of China
| | - Deling Wang
- Department of Medical Imaging
- Sun Yat-sen University Cancer Center
- State Key Laboratory of Oncology in South China
- Collaborative Innovation Center for Cancer Medicine
- Guangzhou
| | - JiaRui Li
- School of Life Sciences
- Shanghai University
- Shanghai 200444
- People's Republic of China
| | - Tao Huang
- Institute of Health Sciences
- Shanghai Institutes for Biological Sciences
- Chinese Academy of Sciences
- Shanghai 200031
- People's Republic of China
| | - Yu-Dong Cai
- School of Life Sciences
- Shanghai University
- Shanghai 200444
- People's Republic of China
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11
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Zhang YZ, Shen HB. Signal-3L 2.0: A Hierarchical Mixture Model for Enhancing Protein Signal Peptide Prediction by Incorporating Residue-Domain Cross-Level Features. J Chem Inf Model 2017; 57:988-999. [PMID: 28298081 DOI: 10.1021/acs.jcim.6b00484] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Signal peptides play key roles in targeting and translocation of integral membrane proteins and secretory proteins. However, signal peptides present several challenges for automatic prediction methods. One challenge is that it is difficult to discriminate signal peptides from transmembrane helices, as both the H-region of the peptides and the transmembrane helices are hydrophobic. Another is that it is difficult to identify the cleavage site between signal peptides and mature proteins, as cleavage motifs or patterns are still unclear for most proteins. To solve these problems and further enhance automatic signal peptide recognition, we report a new Signal-3L 2.0 predictor. Our new model is constructed with a hierarchical protocol, where it first determines the existence of a signal peptide. For this, we propose a new residue-domain cross-level feature-driven approach, and we demonstrate that protein functional domain information is particularly useful for discriminating between the transmembrane helices and signal peptides as they perform different functions. Next, in order to accurately identify the unique signal peptide cleavage sites along the sequence, we designed a top-down approach where a subset of potential cleavage sites are screened using statistical learning rules, and then a final unique site is selected according to its evolution conservation score. Because this mixed approach utilizes both statistical learning and evolution analysis, it shows a strong capacity for recognizing cleavage sites. Signal-3L 2.0 has been benchmarked on multiple data sets, and the experimental results have demonstrated its accuracy. The online server is available at www.csbio.sjtu.edu.cn/bioinf/Signal-3L/ .
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Affiliation(s)
- Yi-Ze Zhang
- Institute of Image Processing and Pattern Recognition, Shanghai Jiao Tong University , Shanghai, 200240, China.,Key Laboratory of System Control and Information Processing, Ministry of Education of China , Shanghai, 200240, China
| | - Hong-Bin Shen
- Institute of Image Processing and Pattern Recognition, Shanghai Jiao Tong University , Shanghai, 200240, China.,Key Laboratory of System Control and Information Processing, Ministry of Education of China , Shanghai, 200240, China
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12
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Khan FI, Govender A, Permaul K, Singh S, Bisetty K. Thermostable chitinase II from Thermomyces lanuginosus SSBP: Cloning, structure prediction and molecular dynamics simulations. J Theor Biol 2015; 374:107-14. [PMID: 25861869 DOI: 10.1016/j.jtbi.2015.03.035] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 03/02/2015] [Accepted: 03/27/2015] [Indexed: 01/02/2023]
Abstract
Thermomyces lanuginosus is a thermophilic fungus that produces large number of industrially-significant enzymes owing to their inherent stability at high temperatures and wide range of pH optima, including thermostable chitinases that have not been fully characterized. Here, we report cloning, characterization and structure prediction of a gene encoding thermostable chitinase II. Sequence analysis revealed that chitinase II gene encodes a 343 amino acid protein of molecular weight 36.65kDa. Our study reports that chitinase II exhibits a well-defined TIM-barrel topology with an eight-stranded α/β domain. Structural analysis and molecular docking studies suggested that Glu176 is essential for enzyme activity. Folding studies of chitinase II using molecular dynamics simulations clearly demonstrated that the stability of the protein was evenly distributed at 350K.
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Affiliation(s)
- Faez Iqbal Khan
- Department of Chemistry, Durban, Steve Biko Campus, Durban University of Technology, Durban, South Africa; Department of Biotechnology and Food Technology, Steve Biko Campus, Durban University of Technology, Durban, South Africa
| | - Algasan Govender
- Department of Biotechnology and Food Technology, Steve Biko Campus, Durban University of Technology, Durban, South Africa
| | - Kugen Permaul
- Department of Biotechnology and Food Technology, Steve Biko Campus, Durban University of Technology, Durban, South Africa
| | - Suren Singh
- Department of Biotechnology and Food Technology, Steve Biko Campus, Durban University of Technology, Durban, South Africa
| | - Krishna Bisetty
- Department of Chemistry, Durban, Steve Biko Campus, Durban University of Technology, Durban, South Africa.
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13
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Massahi A, Çalık P. In-silico determination of Pichia pastoris signal peptides for extracellular recombinant protein production. J Theor Biol 2015; 364:179-88. [DOI: 10.1016/j.jtbi.2014.08.048] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Revised: 08/13/2014] [Accepted: 08/27/2014] [Indexed: 11/29/2022]
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14
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Sharma AR, Chakraborty C, Lee SS, Sharma G, Yoon JK, George Priya Doss C, Song DK, Nam JS. Computational biophysical, biochemical, and evolutionary signature of human R-spondin family proteins, the member of canonical Wnt/β-catenin signaling pathway. BIOMED RESEARCH INTERNATIONAL 2014; 2014:974316. [PMID: 25276837 PMCID: PMC4172882 DOI: 10.1155/2014/974316] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/04/2014] [Revised: 07/12/2014] [Accepted: 07/12/2014] [Indexed: 12/27/2022]
Abstract
In human, Wnt/β-catenin signaling pathway plays a significant role in cell growth, cell development, and disease pathogenesis. Four human (Rspo)s are known to activate canonical Wnt/β-catenin signaling pathway. Presently, (Rspo)s serve as therapeutic target for several human diseases. Henceforth, basic understanding about the molecular properties of (Rspo)s is essential. We approached this issue by interpreting the biochemical and biophysical properties along with molecular evolution of (Rspo)s thorough computational algorithm methods. Our analysis shows that signal peptide length is roughly similar in (Rspo)s family along with similarity in aa distribution pattern. In Rspo3, four N-glycosylation sites were noted. All members are hydrophilic in nature and showed alike GRAVY values, approximately. Conversely, Rspo3 contains the maximum positively charged residues while Rspo4 includes the lowest. Four highly aligned blocks were recorded through Gblocks. Phylogenetic analysis shows Rspo4 is being rooted with Rspo2 and similarly Rspo3 and Rspo1 have the common point of origin. Through phylogenomics study, we developed a phylogenetic tree of sixty proteins (n = 60) with the orthologs and paralogs seed sequences. Protein-protein network was also illustrated. Results demonstrated in our study may help the future researchers to unfold significant physiological and therapeutic properties of (Rspo)s in various disease models.
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Affiliation(s)
- Ashish Ranjan Sharma
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon 200704, Republic of Korea
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University Hospital, College of Medicine, Chuncheon-si, Gangwon-do 200-704, Republic of Korea
| | - Chiranjib Chakraborty
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon 200704, Republic of Korea
- Department of Bioinformatics, School of Computer Sciences, Galgotias University, Greater Noida 203201, India
| | - Sang-Soo Lee
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon 200704, Republic of Korea
| | - Garima Sharma
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon 200704, Republic of Korea
| | - Jeong Kyo Yoon
- Center for Molecular Medicine, Maine Medial Center Research Institute, 81 Research Drive, Scarborough, ME 04074, USA
| | - C. George Priya Doss
- Medical Biotechnology Division, School of Biosciences and Technology, VIT University, Vellore, Tamil Nadu 632014, India
| | - Dong-Keun Song
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon 200704, Republic of Korea
| | - Ju-Suk Nam
- Institute for Skeletal Aging & Orthopedic Surgery, Hallym University-Chuncheon Sacred Heart Hospital, Chuncheon 200704, Republic of Korea
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van Ulsen P, Rahman SU, Jong WS, Daleke-Schermerhorn MH, Luirink J. Type V secretion: From biogenesis to biotechnology. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1843:1592-611. [DOI: 10.1016/j.bbamcr.2013.11.006] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 11/01/2013] [Accepted: 11/13/2013] [Indexed: 12/13/2022]
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16
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Zhang SW, Zhang TH, Zhang JN, Huang Y. Prediction of Signal Peptide Cleavage Sites with Subsite-Coupled and Template Matching Fusion Algorithm. Mol Inform 2014; 33:230-9. [DOI: 10.1002/minf.201300077] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2013] [Accepted: 01/13/2014] [Indexed: 12/22/2022]
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Kazemian HB, Yusuf SA, White K. Signal peptide discrimination and cleavage site identification using SVM and NN. Comput Biol Med 2014; 45:98-110. [PMID: 24480169 DOI: 10.1016/j.compbiomed.2013.11.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 10/28/2013] [Accepted: 11/22/2013] [Indexed: 10/25/2022]
Abstract
About 15% of all proteins in a genome contain a signal peptide (SP) sequence, at the N-terminus, that targets the protein to intracellular secretory pathways. Once the protein is targeted correctly in the cell, the SP is cleaved, releasing the mature protein. Accurate prediction of the presence of these short amino-acid SP chains is crucial for modelling the topology of membrane proteins, since SP sequences can be confused with transmembrane domains due to similar composition of hydrophobic amino acids. This paper presents a cascaded Support Vector Machine (SVM)-Neural Network (NN) classification methodology for SP discrimination and cleavage site identification. The proposed method utilises a dual phase classification approach using SVM as a primary classifier to discriminate SP sequences from Non-SP. The methodology further employs NNs to predict the most suitable cleavage site candidates. In phase one, a SVM classification utilises hydrophobic propensities as a primary feature vector extraction using symmetric sliding window amino-acid sequence analysis for discrimination of SP and Non-SP. In phase two, a NN classification uses asymmetric sliding window sequence analysis for prediction of cleavage site identification. The proposed SVM-NN method was tested using Uni-Prot non-redundant datasets of eukaryotic and prokaryotic proteins with SP and Non-SP N-termini. Computer simulation results demonstrate an overall accuracy of 0.90 for SP and Non-SP discrimination based on Matthews Correlation Coefficient (MCC) tests using SVM. For SP cleavage site prediction, the overall accuracy is 91.5% based on cross-validation tests using the novel SVM-NN model.
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Affiliation(s)
| | | | - K White
- London Metropolitan University, UK
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Grin I, Hartmann MD, Sauer G, Hernandez Alvarez B, Schütz M, Wagner S, Madlung J, Macek B, Felipe-Lopez A, Hensel M, Lupas A, Linke D. A trimeric lipoprotein assists in trimeric autotransporter biogenesis in enterobacteria. J Biol Chem 2013; 289:7388-98. [PMID: 24369174 PMCID: PMC3953254 DOI: 10.1074/jbc.m113.513275] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Trimeric autotransporter adhesins (TAAs) are important virulence factors of many Gram-negative bacterial pathogens. TAAs form fibrous, adhesive structures on the bacterial cell surface. Their N-terminal extracellular domains are exported through a C-terminal membrane pore; the insertion of the pore domain into the bacterial outer membrane follows the rules of β-barrel transmembrane protein biogenesis and is dependent on the essential Bam complex. We have recently described the full fiber structure of SadA, a TAA of unknown function in Salmonella and other enterobacteria. In this work, we describe the structure and function of SadB, a small inner membrane lipoprotein. The sadB gene is located in an operon with sadA; orthologous operons are only found in enterobacteria, whereas other TAAs are not typically associated with lipoproteins. Strikingly, SadB is also a trimer, and its co-expression with SadA has a direct influence on SadA structural integrity. This is the first report of a specific export factor of a TAA, suggesting that at least in some cases TAA autotransport is assisted by additional periplasmic proteins.
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Affiliation(s)
- Iwan Grin
- From the Max Planck Institut für Entwicklungsbiologie, 72076 Tübingen
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de Baaij JHF, Stuiver M, Meij IC, Lainez S, Kopplin K, Venselaar H, Müller D, Bindels RJM, Hoenderop JGJ. Membrane topology and intracellular processing of cyclin M2 (CNNM2). J Biol Chem 2012; 287:13644-55. [PMID: 22399287 DOI: 10.1074/jbc.m112.342204] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Recently, mutations in the cyclin M2 (CNNM2) gene were identified to be causative for severe hypomagnesemia. In kidney, CNNM2 is a basolaterally expressed protein with predominant expression in the distal convoluted tubule. Transcellular magnesium (Mg(2+)) reabsorption in the distal convoluted tubule represents the final step before Mg(2+) is excreted into the urine, thus fine-tuning its final excretion via a tightly regulated mechanism. The present study aims to get insight in the structure of CNNM2 and to characterize its post-translational modifications. Here, membrane topology studies using intramolecular epitopes and immunocytochemistry showed that CNNM2 has an extracellular N terminus and an intracellular C terminus. This suggests that one of the predicted transmembrane regions might be re-entrant. By homology modeling, we demonstrated that the loss-of-function mutation as found in patients disturbs the potential ATP binding by the intracellular cystathionine β-synthase domains. In addition, the cellular processing pathway of CNNM2 was exposed in detail. In the endoplasmic reticulum, the signal peptidase complex cleaves off a large N-terminal signal peptide of about 64 amino acids. Mutagenesis screening showed that CNNM2 is glycosylated at residue Asn-112, stabilizing CNNM2 on the plasma membrane. Interestingly, co-immunoprecipitation studies evidenced that CNNM2a forms heterodimers with the smaller isoform CNNM2b. These new findings on CNNM2 structure and processing may aid to elucidate the physiological role of CNNM2 in Mg(2+) reabsorption in the kidney.
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Affiliation(s)
- Jeroen H F de Baaij
- Department of Physiology, Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, 6500 HB Nijmegen, The Netherlands
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20
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Requirements for mouse mammary tumor virus Rem signal peptide processing and function. J Virol 2011; 86:214-25. [PMID: 22072771 DOI: 10.1128/jvi.06197-11] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mouse mammary tumor virus (MMTV) encodes a Rev-like protein, Rem, which is involved in the nuclear export and expression of viral RNA. Previous data have shown that all Rev-like functions are localized to the 98-amino-acid signal peptide (SP) at the N terminus of MMTV Rem or envelope proteins. MMTV-SP uses endoplasmic reticulum-associated degradation (ERAD) for protein trafficking. Rem cleavage by signal peptidase in the ER is necessary for MMTV-SP function in a reporter assay, but many requirements for trafficking are not known. To allow detection and localization of both MMTV-SP and the C-terminal cleavage product, we prepared plasmids expressing green fluorescent protein (GFP) tags. N-terminal Rem tagging led to protein accumulation relative to untagged Rem and allowed signal peptidase cleavage but reduced its specific activity. C-terminal tagging also led to Rem accumulation yet dramatically reduced cleavage, GFP fluorescence, and activity relative to N-terminally tagged Rem (GFPRem). Substitutions of an invariant leucine at position 71 between the known RNA-binding and nuclear export sequences interfered with GFPRem accumulation and activity but not cleavage. Similarly, deletion of 100 or 150 C-terminal amino acids from GFPRem dramatically reduced both Rem and MMTV-SP levels and function. Removal of the entire C terminus (203 amino acids) restored both protein levels and activity of MMTV-SP. Only C-terminal GFP tagging, and not other modifications, appeared to trap Rem in the ER membrane. Thus, Rem conformation in both the ER lumen and cytoplasm determines cleavage, retrotranslocation, and MMTV-SP function. These mutants further characterize intermediates in Rem trafficking and have implications for all proteins affected by ERAD.
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21
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Yap MN, Bernstein HD. The translational regulatory function of SecM requires the precise timing of membrane targeting. Mol Microbiol 2011; 81:540-53. [PMID: 21635582 DOI: 10.1111/j.1365-2958.2011.07713.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In Escherichia coli, secA expression is regulated at the translational level by an upstream gene (secM) that encodes a presecretory protein. SecM contains a C-terminal sequence motif that induces a transient translation arrest. Inhibition of SecM membrane targeting prolongs the translation arrest and increases SecA synthesis by concomitantly altering the structure of the secM-secA mRNA. Here we show that the SecM signal peptide plays an essential role in this regulatory process by acting as a molecular timer that co-ordinates membrane targeting with the synthesis of the arrest motif. We found that signal peptide mutations that alter targeting kinetics and insertions or deletions that change the distance between the SecM signal peptide and the arrest motif perturb the balance between the onset and release of arrest that is required to regulate SecA synthesis. Furthermore, we found that the strength of the interaction between the ribosome and the SecM arrest motif is calibrated to ensure the release of arrest upon membrane targeting. Our results strongly suggest that several distinctive features of the SecM protein evolved as a consequence of constraints imposed by the ribosome and the Sec machinery.
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Affiliation(s)
- Mee-Ngan Yap
- Genetics and Biochemistry Branch, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
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22
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Yu X, Zheng X, Liu T, Dou Y, Wang J. Predicting subcellular location of apoptosis proteins with pseudo amino acid composition: approach from amino acid substitution matrix and auto covariance transformation. Amino Acids 2011; 42:1619-25. [DOI: 10.1007/s00726-011-0848-8] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Accepted: 02/09/2011] [Indexed: 12/13/2022]
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Resch E, Hiss JA, Schreiner A, Schneider G, Starzinski-Powitz A. Long signal peptides of RGMa and DCBLD2 are dissectible into subdomains according to the NtraC model. ACTA ACUST UNITED AC 2011; 7:942-51. [DOI: 10.1039/c0mb00254b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Abstract
Since the proposal of the signal hypothesis on protein subcellular sorting, a number of computational analyses have been performed in this field. A typical example is the development of prediction algorithms for the subcellular localization sites of input protein sequences. In this review, we mainly focus on the biological grounds of the prediction methods rather than the algorithmic issues because we believe the former will be more fruitful for future development. Recent advances on the study of protein sorting signals will hopefully be incorporated into future prediction methods. Unfortunately, many of the state-of-the-art methods are published without sufficient objective tests. In fact, a simple test employed in this article shows that the performance of specifically developed predictors is not significantly better than that of a homology search. We suspect that this is a general problem associated with the interpretation of genome sequences, which have evolved through gene duplication and speciation.
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Affiliation(s)
- Kenichiro Imai
- Computational Biology Research Center, AIST, Tokyo, Japan
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