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Characterization of AtBAG2 as a Novel Molecular Chaperone. Life (Basel) 2023; 13:life13030687. [PMID: 36983842 PMCID: PMC10052705 DOI: 10.3390/life13030687] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Revised: 12/31/2022] [Accepted: 12/31/2022] [Indexed: 03/06/2023] Open
Abstract
Bcl-2-associated anthanogene (BAG) family proteins regulate plant defense against biotic and abiotic stresses; however, the function and precise mechanism of action of each individual BAG protein are not yet clear. In this study, we investigated the biochemical and molecular functions of the Arabidopsis thaliana BAG2 (AtBAG2) protein, and elucidated its physiological role under stress conditions using mutant plants and transgenic yeast strains. The T-DNA insertion atbag2 mutant plants were highly susceptible to heat shock, whereas transgenic yeast strains ectopically expressing AtBAG2 exhibited outstanding thermotolerance. Moreover, a biochemical analysis of GST-fused recombinant proteins produced in bacteria revealed that AtBAG2 exhibits molecular chaperone activity, which could be attributed to its BAG domain. The relevance of the molecular chaperone function of AtBAG2 to the cellular heat stress response was confirmed using yeast transformants, and the experimental results showed that overexpression of the AtBAG2 sequence encoding only the BAG domain was sufficient to impart thermotolerance. Overall, these results suggest that the BAG domain-dependent molecular chaperone activity of AtBAG2 is indispensable for the heat stress response of Arabidopsis. This is the first report demonstrating the role of AtBAG2 as a sole molecular chaperone in Arabidopsis.
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Saini LK, Bheri M, Pandey GK. Protein phosphatases and their targets: Comprehending the interactions in plant signaling pathways. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2023; 134:307-370. [PMID: 36858740 DOI: 10.1016/bs.apcsb.2022.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Protein phosphorylation is a vital reversible post-translational modification. This process is established by two classes of enzymes: protein kinases and protein phosphatases. Protein kinases phosphorylate proteins while protein phosphatases dephosphorylate phosphorylated proteins, thus, functioning as 'critical regulators' in signaling pathways. The eukaryotic protein phosphatases are classified as phosphoprotein phosphatases (PPP), metallo-dependent protein phosphatases (PPM), protein tyrosine (Tyr) phosphatases (PTP), and aspartate (Asp)-dependent phosphatases. The PPP and PPM families are serine (Ser)/threonine (Thr) specific phosphatases (STPs) that dephosphorylate Ser and Thr residues. The PTP family dephosphorylates Tyr residues while dual-specificity phosphatases (DsPTPs/DSPs) dephosphorylate Ser, Thr, and Tyr residues. The composition of these enzymes as well as their substrate specificity are important determinants of their functional significance in a number of cellular processes and stress responses. Their role in animal systems is well-understood and characterized. The functional characterization of protein phosphatases has been extensively covered in plants, although the comprehension of their mechanistic basis is an ongoing pursuit. The nature of their interactions with other key players in the signaling process is vital to our understanding. The substrates or targets determine their potential as well as magnitude of the impact they have on signaling pathways. In this article, we exclusively overview the various substrates of protein phosphatases in plant signaling pathways, which are a critical determinant of the outcome of various developmental and stress stimuli.
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Affiliation(s)
- Lokesh K Saini
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, India
| | - Malathi Bheri
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, India
| | - Girdhar K Pandey
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, India.
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Muthusamy M, Kim JH, Kim SH, Park SY, Lee SI. BrPP5.2 Overexpression Confers Heat Shock Tolerance in Transgenic Brassica rapa through Inherent Chaperone Activity, Induced Glucosinolate Biosynthesis, and Differential Regulation of Abiotic Stress Response Genes. Int J Mol Sci 2021; 22:ijms22126437. [PMID: 34208567 PMCID: PMC8234546 DOI: 10.3390/ijms22126437] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/14/2021] [Accepted: 06/14/2021] [Indexed: 12/13/2022] Open
Abstract
Plant phosphoprotein phosphatases are ubiquitous and multifarious enzymes that respond to developmental requirements and stress signals through reversible dephosphorylation of target proteins. In this study, we investigated the hitherto unknown functions of Brassica rapa protein phosphatase 5.2 (BrPP5.2) by transgenic overexpression of B. rapa lines. The overexpression of BrPP5.2 in transgenic lines conferred heat shock tolerance in 65–89% of the young transgenic seedlings exposed to 46 °C for 25 min. The examination of purified recombinant BrPP5.2 at different molar ratios efficiently prevented the thermal aggregation of malate dehydrogenase at 42 °C, thus suggesting that BrPP5.2 has inherent chaperone activities. The transcriptomic dynamics of transgenic lines, as determined using RNA-seq, revealed that 997 and 1206 (FDR < 0.05, logFC ≥ 2) genes were up- and down-regulated, as compared to non-transgenic controls. Statistical enrichment analyses revealed abiotic stress response genes, including heat stress response (HSR), showed reduced expression in transgenic lines under optimal growth conditions. However, most of the HSR DEGs were upregulated under high temperature stress (37 °C/1 h) conditions. In addition, the glucosinolate biosynthesis gene expression and total glucosinolate content increased in the transgenic lines. These findings provide a new avenue related to BrPP5.2 downstream genes and their crucial metabolic and heat stress responses in plants.
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Affiliation(s)
- Muthusamy Muthusamy
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences (NAS), Rural Development Administration, Jeonju 54874, Korea; (M.M.); (J.H.K.); (S.H.K.); (S.Y.P.)
| | - Jong Hee Kim
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences (NAS), Rural Development Administration, Jeonju 54874, Korea; (M.M.); (J.H.K.); (S.H.K.); (S.Y.P.)
- Division of Horticultural Biotechnology, Hankyung National University, Anseong 17579, Korea
| | - Suk Hee Kim
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences (NAS), Rural Development Administration, Jeonju 54874, Korea; (M.M.); (J.H.K.); (S.H.K.); (S.Y.P.)
| | - So Young Park
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences (NAS), Rural Development Administration, Jeonju 54874, Korea; (M.M.); (J.H.K.); (S.H.K.); (S.Y.P.)
| | - Soo In Lee
- Department of Agricultural Biotechnology, National Institute of Agricultural Sciences (NAS), Rural Development Administration, Jeonju 54874, Korea; (M.M.); (J.H.K.); (S.H.K.); (S.Y.P.)
- Correspondence: ; Tel.: +82-63-238-4618; Fax: +82-63-238-4604
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Liu H, Chen H, Ding G, Li K, Wang Y. Proteomic Insight into the Symbiotic Relationship of Pinus massoniana Lamb and Suillus luteus towards Developing Al-Stress Resistance. Life (Basel) 2021; 11:177. [PMID: 33672434 PMCID: PMC7926926 DOI: 10.3390/life11020177] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Revised: 02/18/2021] [Accepted: 02/20/2021] [Indexed: 12/30/2022] Open
Abstract
Global warming significantly impacts forest range areas by increasing soil acidification or aluminum toxicity. Aluminum (Al) toxicity retards plant growth by inhibiting the root development process, hindering water uptake, and limiting the bioavailability of other essential micronutrients. Pinus massoniana (masson pine), globally recognized as a reforestation plant, is resistant to stress conditions including biotic and abiotic stresses. This resistance is linked to the symbiotic relationship with diverse ectomycorrhizal fungal species. In the present study, we investigated the genetic regulators as expressed proteins, conferring a symbiotic relationship between Al-stress resistance and Suillus luteus in masson pine. Multi-treatment trials resulted in the identification of 12 core Al-stress responsive proteins conserved between Al stress conditions with or without S. luteus inoculation. These proteins are involved in chaperonin CPN60-2, protein refolding and ATP-binding, Cu-Zn-superoxide dismutase precursor, oxidation-reduction process, and metal ion binding, phosphoglycerate kinase 1, glycolytic process, and metabolic process. Furthermore, 198 Al responsive proteins were identified specifically under S. luteus-inoculation and are involved in gene regulation, metabolic process, oxidation-reduction process, hydrolase activity, and peptide activity. Chlorophyll a-b binding protein, endoglucanase, putative spermidine synthase, NADH dehydrogenase, and glutathione-S-transferase were found with a significant positive expression under a combined Al and S. luteus treatment, further supported by the up-regulation of their corresponding genes. This study provides a theoretical foundation for exploiting the regulatory role of ectomycorrhizal inoculation and associated genetic changes in resistance against Al stress in masson pine.
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Affiliation(s)
- Haiyan Liu
- Institute for Forest Resources & Environment of Guizhou, Guiyang 550025, China; (H.L.); (H.C.); (K.L.)
- Guizhou Botanical Garden, Guiyang 550004, China;
| | - Houying Chen
- Institute for Forest Resources & Environment of Guizhou, Guiyang 550025, China; (H.L.); (H.C.); (K.L.)
| | - Guijie Ding
- Institute for Forest Resources & Environment of Guizhou, Guiyang 550025, China; (H.L.); (H.C.); (K.L.)
| | - Kuaifen Li
- Institute for Forest Resources & Environment of Guizhou, Guiyang 550025, China; (H.L.); (H.C.); (K.L.)
| | - Yao Wang
- Guizhou Botanical Garden, Guiyang 550004, China;
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5
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Struk S, De Cuyper C, Jacobs A, Braem L, Walton A, De Keyser A, Depuydt S, Vu LD, De Smet I, Boyer FD, Eeckhout D, Persiau G, Gevaert K, De Jaeger G, Goormachtig S. Unraveling the MAX2 Protein Network in Arabidopsis thaliana: Identification of the Protein Phosphatase PAPP5 as a Novel MAX2 Interactor. Mol Cell Proteomics 2021; 20:100040. [PMID: 33372050 PMCID: PMC7950214 DOI: 10.1074/mcp.ra119.001766] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/18/2020] [Accepted: 12/28/2020] [Indexed: 12/12/2022] Open
Abstract
The F-box protein MORE AXILLARY GROWTH 2 (MAX2) is a central component in the signaling cascade of strigolactones (SLs) as well as of the smoke-derived karrikins (KARs) and the so far unknown endogenous KAI2 ligand (KL). The two groups of molecules are involved in overlapping and unique developmental processes, and signal-specific outcomes are attributed to perception by the paralogous α/β-hydrolases DWARF14 (D14) for SL and KARRIKIN INSENSITIVE 2/HYPOSENSITIVE TO LIGHT (KAI2/HTL) for KAR/KL. In addition, depending on which receptor is activated, specific members of the SUPPRESSOR OF MAX2 1 (SMAX1)-LIKE (SMXL) family control KAR/KL and SL responses. As proteins that function in the same signal transduction pathway often occur in large protein complexes, we aimed at discovering new players of the MAX2, D14, and KAI2 protein network by tandem affinity purification in Arabidopsis cell cultures. When using MAX2 as a bait, various proteins were copurified, among which were general components of the Skp1-Cullin-F-box complex and members of the CONSTITUTIVE PHOTOMORPHOGENIC 9 signalosome. Here, we report the identification of a novel interactor of MAX2, a type 5 serine/threonine protein phosphatase, designated PHYTOCHROME-ASSOCIATED PROTEIN PHOSPHATASE 5 (PAPP5). Quantitative affinity purification pointed at PAPP5 as being more present in KAI2 rather than in D14 protein complexes. In agreement, mutant analysis suggests that PAPP5 modulates KAR/KL-dependent seed germination under suboptimal conditions and seedling development. In addition, a phosphopeptide enrichment experiment revealed that PAPP5 might dephosphorylate MAX2 in vivo independently of the synthetic SL analog, rac-GR24. Together, by analyzing the protein complexes to which MAX2, D14, and KAI2 belong, we revealed a new MAX2 interactor, PAPP5, that might act through dephosphorylation of MAX2 to control mainly KAR/KL-related phenotypes and, hence, provide another link with the light pathway.
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Affiliation(s)
- Sylwia Struk
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Carolien De Cuyper
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Anse Jacobs
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium; Department of Biochemistry, Ghent University, Ghent, Belgium; Center for Medical Biotechnology, VIB, Ghent, Belgium
| | - Lukas Braem
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium; Department of Biochemistry, Ghent University, Ghent, Belgium; Center for Medical Biotechnology, VIB, Ghent, Belgium
| | - Alan Walton
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium; Department of Biochemistry, Ghent University, Ghent, Belgium; Center for Medical Biotechnology, VIB, Ghent, Belgium
| | - Annick De Keyser
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Stephen Depuydt
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Lam Dai Vu
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium; Department of Biochemistry, Ghent University, Ghent, Belgium; Center for Medical Biotechnology, VIB, Ghent, Belgium
| | - Ive De Smet
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - François-Didier Boyer
- Institut Jean-Pierre Bourgin, Institut National de la Recherche Agronomique (INRA), AgroParisTech, Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, Versailles, France; Institut de Chimie des Substances Naturelles, CNRS Unité Propre de Recherche 2301, Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Dominique Eeckhout
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Geert Persiau
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Kris Gevaert
- Department of Biochemistry, Ghent University, Ghent, Belgium; Center for Medical Biotechnology, VIB, Ghent, Belgium
| | - Geert De Jaeger
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium
| | - Sofie Goormachtig
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Ghent, Belgium; Center for Plant Systems Biology, VIB, Ghent, Belgium.
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6
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Bheri M, Mahiwal S, Sanyal SK, Pandey GK. Plant protein phosphatases: What do we know about their mechanism of action? FEBS J 2020; 288:756-785. [PMID: 32542989 DOI: 10.1111/febs.15454] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 05/27/2020] [Accepted: 06/09/2020] [Indexed: 12/30/2022]
Abstract
Protein phosphorylation is a major reversible post-translational modification. Protein phosphatases function as 'critical regulators' in signaling networks through dephosphorylation of proteins, which have been phosphorylated by protein kinases. A large understanding of their working has been sourced from animal systems rather than the plant or the prokaryotic systems. The eukaryotic protein phosphatases include phosphoprotein phosphatases (PPP), metallo-dependent protein phosphatases (PPM), protein tyrosine (Tyr) phosphatases (PTP), and aspartate (Asp)-dependent phosphatases. The PPP and PPM families are serine(Ser)/threonine(Thr)-specific phosphatases (STPs), while PTP family is Tyr specific. Dual-specificity phosphatases (DsPTPs/DSPs) dephosphorylate Ser, Thr, and Tyr residues. PTPs lack sequence homology with STPs, indicating a difference in catalytic mechanisms, while the PPP and PPM families share a similar structural fold indicating a common catalytic mechanism. The catalytic cysteine (Cys) residue in the conserved HCX5 R active site motif of the PTPs acts as a nucleophile during hydrolysis. The PPP members require metal ions, which coordinate the phosphate group of the substrate, followed by a nucleophilic attack by a water molecule and hydrolysis. The variable holoenzyme assembly of protein phosphatase(s) and the overlap with other post-translational modifications like acetylation and ubiquitination add to their complexity. Though their functional characterization is extensively reported in plants, the mechanistic nature of their action is still being explored by researchers. In this review, we exclusively overview the plant protein phosphatases with an emphasis on their mechanistic action as well as structural characteristics.
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Affiliation(s)
- Malathi Bheri
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Swati Mahiwal
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Sibaji K Sanyal
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
| | - Girdhar K Pandey
- Department of Plant Molecular Biology, University of Delhi South Campus, New Delhi, India
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7
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AtTPR10 Containing Multiple ANK and TPR Domains Exhibits Chaperone Activity and Heat-Shock Dependent Structural Switching. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10041265] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Among the several tetratricopeptide (TPR) repeat-containing proteins encoded by the Arabidopsis thaliana genome, AtTPR10 exhibits an atypical structure with three TPR domain repeats at the C-terminus in addition to seven ankyrin (ANK) domain repeats at the N-terminus. However, the function of AtTPR10 remains elusive. Here, we investigated the biochemical function of AtTPR10. Bioinformatic analysis revealed that AtTPR10 expression is highly enhanced by heat shock compared with the other abiotic stresses, suggesting that AtTPR10 functions as a molecular chaperone to protect intracellular proteins from thermal stresses. Under the heat shock treatment, the chaperone activity of AtTPR10 increased significantly; this was accompanied by a structural switch from the low molecular weight (LMW) protein to a high molecular weight (HMW) complex. Analysis of two truncated fragments of AtTPR10 containing the TPR and ANK repeats showed that each domain exhibits a similar range of chaperone activity (approximately one-third of that of the native protein), suggesting that each domain cooperatively regulates the chaperone function of AtTPR10. Additionally, both truncated fragments of AtTPR10 underwent structural reconfiguration to form heat shock-dependent HMW complexes. Our results clearly demonstrate that AtTPR10 functions as a molecular chaperone in plants to protect intracellular targets from heat shock stress.
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Grancieri M, Martino HSD, Gonzalez de Mejia E. Chia Seed (Salvia hispanica L.) as a Source of Proteins and Bioactive Peptides with Health Benefits: A Review. Compr Rev Food Sci Food Saf 2019; 18:480-499. [PMID: 33336944 DOI: 10.1111/1541-4337.12423] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/23/2018] [Accepted: 12/26/2018] [Indexed: 12/12/2022]
Abstract
The consumption of chia seed (Salvia hispanica L.) has increased in recent years due its high content of omega-3 fatty acids and dietary fiber. This seed also has a high concentration of proteins and essential amino acids, becoming a promising source of bioactive peptides. The objective of this review was to identify the composition and the beneficial effects of chia seeds (S. hispanica L.), their proteins, peptides, and their potential impact on human health. The UniProt database was used to identify the chia proteins and their amino acid sequences. The BIOPEP database was used to analyze the peptides's bioactive potential. A total of 20 proteins were cataloged in chia seed, 12 of those were involved in the regular metabolic processes of the plant cells. However, eight proteins were specifically related to production and storage of plant lipids, thus explaining the high concentration of lipids in chia seeds (around 30%), especially omega-3 fatty acids (around 20%). The analyses of amino acid sequences showed peptides with bioactive potential, including dipeptidyl peptidase-IV inhibitors, angiotensin-converting enzyme inhibitors, and antioxidant capacity. These results correlated with the main health benefits of whole chia seed in humans such as antioxidant capacity, and hypotensive, hypoglycemic, and anticholesterolemic effects. Such relation can be associated with chia protein and peptide compositions and therefore needs further investigation in vitro and in vivo.
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Affiliation(s)
- Mariana Grancieri
- Dept. de Nutrição e Saúde, Univ. Federal de Viçosa, Viçosa, MG, Brazil.,Dept. of Food Science & Human Nutrition, Univ. of Illinois at Urbana-Champaign, IL, U.S.A
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9
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Exploring Novel Functions of the Small GTPase Ypt1p under Heat-Shock by Characterizing a Temperature-Sensitive Mutant Yeast Strain, ypt1-G80D. Int J Mol Sci 2019; 20:ijms20010132. [PMID: 30609659 PMCID: PMC6337079 DOI: 10.3390/ijms20010132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2018] [Revised: 12/08/2018] [Accepted: 12/08/2018] [Indexed: 02/06/2023] Open
Abstract
In our previous study, we found that Ypt1p, a Rab family small GTPase protein, exhibits a stress-driven structural and functional switch from a GTPase to a molecular chaperone, and mediates thermo tolerance in Saccharomyces cerevisiae. In the current study, we focused on the temperature-sensitive ypt1-G80D mutant, and found that the mutant cells are highly sensitive to heat-shock, due to a deficiency in the chaperone function of Ypt1pG80D. This defect results from an inability of the protein to form high molecular weight polymers, even though it retains almost normal GTPase function. The heat-stress sensitivity of ypt1-G80D cells was partially recovered by treatment with 4-phenylbutyric acid, a chemical chaperone. These findings indicate that loss of the chaperone function of Ypt1pG80D underlies the heat sensitivity of ypt1-G80D cells. We also compared the proteomes of YPT1 (wild-type) and ypt1-G80D cells to investigate Ypt1p-controlled proteins under heat-stress conditions. Our findings suggest that Ypt1p controls an abundance of proteins involved in metabolism, protein synthesis, cellular energy generation, stress response, and DNA regulation. Finally, we suggest that Ypt1p essentially regulates fundamental cellular processes under heat-stress conditions by acting as a molecular chaperone.
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10
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Cha JY, Kim J, Kim TS, Zeng Q, Wang L, Lee SY, Kim WY, Somers DE. GIGANTEA is a co-chaperone which facilitates maturation of ZEITLUPE in the Arabidopsis circadian clock. Nat Commun 2017; 8:3. [PMID: 28232745 PMCID: PMC5431898 DOI: 10.1038/s41467-016-0014-9] [Citation(s) in RCA: 86] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Accepted: 11/17/2016] [Indexed: 12/15/2022] Open
Abstract
Circadian clock systems help establish the correct daily phasing of the behavioral, developmental, and molecular events needed for the proper coordination of physiology and metabolism. The circadian oscillator comprises transcription–translation feedback loops but also requires post-translational processes that regulate clock protein homeostasis. GIGANTEA is a unique plant protein involved in the maintenance and control of numerous facets of plant physiology and development. Through an unknown mechanism GIGANTEA stabilizes the F-box protein ZEITLUPE, a key regulator of the circadian clock. Here, we show that GIGANTEA has general protein chaperone activity and can act to specifically facilitate ZEITLUPE maturation into an active form in vitro and in planta. GIGANTEA forms a ternary complex with HSP90 and ZEITLUPE and its co-chaperone action synergistically enhances HSP90/HSP70 maturation of ZEITLUPE in vitro. These results identify a molecular mechanism for GIGANTEA activity that can explain its wide-ranging role in plant biology. The plant-specific GIGANTEA protein regulates the circadian clock by stabilizing the F-box protein ZEITLUPE via an unknown mechanism. Here Cha et al. show that GIGANTEA has intrinsic chaperone activity and can facilitate ZEITLUPE maturation by acting synergistically with HSP90.
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Affiliation(s)
- Joon-Yung Cha
- Division of Applied Life Science (BK21Plus), PMBBRC &IALS, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Jeongsik Kim
- Department of Molecular Genetics, The Ohio State University, Columbus, 43210, USA.,Center for Plant Aging Research, Institute for Basic Science (IBS), Daegu, 711-873, Republic of Korea
| | - Tae-Sung Kim
- Department of Molecular Genetics, The Ohio State University, Columbus, 43210, USA.,Department of Agricultural Sciences, Korea National Open University, Seoul, 03087, Republic of Korea
| | - Qingning Zeng
- Department of Molecular Genetics, The Ohio State University, Columbus, 43210, USA
| | - Lei Wang
- Department of Molecular Genetics, The Ohio State University, Columbus, 43210, USA.,Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing, 100093, China
| | - Sang Yeol Lee
- Division of Applied Life Science (BK21Plus), PMBBRC &IALS, Gyeongsang National University, Jinju, 52828, Republic of Korea
| | - Woe-Yeon Kim
- Division of Applied Life Science (BK21Plus), PMBBRC &IALS, Gyeongsang National University, Jinju, 52828, Republic of Korea.
| | - David E Somers
- Department of Molecular Genetics, The Ohio State University, Columbus, 43210, USA.
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11
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Nawkar GM, Maibam P, Park JH, Woo SG, Kim CY, Lee SY, Kang CH. In silico study on Arabidopsis BAG gene expression in response to environmental stresses. PROTOPLASMA 2017; 254:409-421. [PMID: 27002965 PMCID: PMC5216074 DOI: 10.1007/s00709-016-0961-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Accepted: 03/10/2016] [Indexed: 05/13/2023]
Abstract
BAG (Bcl-2 athanogene) family proteins are conserved in a wide range of eukaryotes, and they have been proposed to play a crucial role in plant programmed cell death (PCD). During the past decade, with the help of advanced bioinformatics tools, seven homologs of BAG genes have been identified in the Arabidopsis genome; these genes are involved in pathogen attack and abiotic stress conditions. In this study, gene expression of Arabidopsis BAG family members under environmental stresses was analyzed using the Botany Array Resource (BAR) expression browser tool and the in silico data were partially confirmed by qRT-PCR analysis for the selected stress- and hormone-treated conditions related to environmental stresses. Particularly, the induction of AtBAG6 gene in response to heat shock was confirmed by using GUS reporter lines. The loss of the AtBAG6 gene resulted into impairment in basal thermotolerance of plant and showed enhanced cell death in response to heat stress. To elucidate the regulatory mechanisms of BAG genes, we analyzed ∼1-kbp promoter regions for the presence of stress-responsive elements. Our transcription profiling finally revealed that the Arabidopsis BAG genes differentially respond to environmental stresses under the control of specifically organized upstream regulatory elements.
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Affiliation(s)
- Ganesh M Nawkar
- Division of Applied Life Science and PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea
| | - Punyakishore Maibam
- Division of Applied Life Science and PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea
| | - Joung Hun Park
- Division of Applied Life Science and PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea
| | - Su Gyeong Woo
- Eco-friendly Bio-Material Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, 580-185, Republic of Korea
| | - Cha Young Kim
- Eco-friendly Bio-Material Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Jeongeup, 580-185, Republic of Korea
| | - Sang Yeol Lee
- Division of Applied Life Science and PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea.
| | - Chang Ho Kang
- Division of Applied Life Science and PMBBRC, Gyeongsang National University, 501 Jinju-daero, Jinju, 52828, Republic of Korea.
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12
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Aluminum Toxicity-Induced Alterations of Leaf Proteome in Two Citrus Species Differing in Aluminum Tolerance. Int J Mol Sci 2016; 17:ijms17071180. [PMID: 27455238 PMCID: PMC4964550 DOI: 10.3390/ijms17071180] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 07/13/2016] [Accepted: 07/13/2016] [Indexed: 11/17/2022] Open
Abstract
Seedlings of aluminum-tolerant ‘Xuegan’ (Citrus sinensis) and Al-intolerant ‘sour pummelo’ (Citrus grandis) were fertigated for 18 weeks with nutrient solution containing 0 and 1.2 mM AlCl3·6H2O. Al toxicity-induced inhibition of photosynthesis and the decrease of total soluble protein only occurred in C. grandis leaves, demonstrating that C. sinensis had higher Al tolerance than C. grandis. Using isobaric tags for relative and absolute quantification (iTRAQ), we obtained more Al toxicity-responsive proteins from C. sinensis than from C. grandis leaves, which might be responsible for the higher Al tolerance of C. sinensis. The following aspects might contribute to the Al tolerance of C. sinensis: (a) better maintenance of photosynthesis and energy balance via inducing photosynthesis and energy-related proteins; (b) less increased requirement for the detoxification of reactive oxygen species and other toxic compounds, such as aldehydes, and great improvement of the total ability of detoxification; and (c) upregulation of low-phosphorus-responsive proteins. Al toxicity-responsive proteins related to RNA regulation, protein metabolism, cellular transport and signal transduction might also play key roles in the higher Al tolerance of C. sinensis. We present the global picture of Al toxicity-induced alterations of protein profiles in citrus leaves, and identify some new Al toxicity-responsive proteins related to various biological processes. Our results provide some novel clues about plant Al tolerance.
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13
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Kang CH, Lee YM, Park JH, Nawkar GM, Oh HT, Kim MG, Lee SI, Kim WY, Yun DJ, Lee SY. Ribosomal P3 protein AtP3B of Arabidopsis acts as both protein and RNA chaperone to increase tolerance of heat and cold stresses. PLANT, CELL & ENVIRONMENT 2016; 39:1631-42. [PMID: 27004478 DOI: 10.1111/pce.12742] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/01/2016] [Revised: 03/01/2016] [Accepted: 03/03/2016] [Indexed: 05/16/2023]
Abstract
The P3 proteins are plant-specific ribosomal P-proteins; however, their molecular functions have not been characterized. In a screen for components of heat-stable high-molecular weight (HMW) complexes, we isolated the P3 protein AtP3B from heat-treated Arabidopsis suspension cultures. By size-exclusion chromatography (SEC), SDS-PAGE and native PAGE followed by immunoblotting with anti-AtP3B antibody, we showed that AtP3B was stably retained in HMW complexes following heat shock. The level of AtP3B mRNA increased in response to both high- and low-temperature stresses. Bacterially expressed recombinant AtP3B protein exhibited both protein and RNA chaperone activities. Knockdown of AtP3B by RNAi made plants sensitive to both high- and low-temperature stresses, whereas overexpression of AtP3B increased tolerance of both conditions. Together, our results suggest that AtP3B protects cells against both high- and low-temperature stresses. These findings provide novel insight into the molecular functions and in vivo roles of acidic ribosomal P-proteins, thereby expanding our knowledge of the protein production machinery.
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Affiliation(s)
- Chang Ho Kang
- Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea
| | - Young Mee Lee
- Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea
- Genetics and Breeding Research Center, NFRDI, Geoje, 656-842, Korea
| | - Joung Hun Park
- Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea
| | - Ganesh M Nawkar
- Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea
| | - Hun Taek Oh
- Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea
| | - Min Gab Kim
- College of Pharmacy and Research Institute of Pharmaceutical Science, Gyeongsang National University, Jinju, 660-701, Korea
| | - Soo In Lee
- Department of Agricultural Biotechnology, National Academy of Agricultural Science (NAAS), Jeonju, 560-500, Korea
| | - Woe Yeon Kim
- Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea
| | - Dae-Jin Yun
- Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea
| | - Sang Yeol Lee
- Division of Applied Life Sciences (BK21+) and Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju, 660-701, Korea
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14
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Xie L, Fang W, Deng W, Yu Z, Li J, Chen M, Liao W, Xie J, Pan W. Global profiling of lysine acetylation in human histoplasmosis pathogen Histoplasma capsulatum. Int J Biochem Cell Biol 2016; 73:1-10. [PMID: 26806293 DOI: 10.1016/j.biocel.2016.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 12/29/2015] [Accepted: 01/15/2016] [Indexed: 11/16/2022]
Abstract
Histoplasma capsulatum is the causative agent of human histoplasmosis, which can cause respiratory and systemic mycosis in immune-compromised individuals. Lysine acetylation, a protein posttranslational protein modification, is widespread in both eukaryotes and prokaryotes. Although increasing evidence suggests that lysine acetylation may play critical roles in fungus physiology, very little is known about its extent and function in H. capsulatum. To comprehensively profile protein lysine acetylation in H. capsulatum, we performed a global acetylome analysis through peptide prefractionation, antibody enrichment, and LC-MS/MS analysis, identifying 775 acetylation sites on 456 acetylated proteins; and functionally analysis showing their involvement in different biological processes. We defined six types of acetylation site motifs, and the results imply that lysine residue of polypeptide with tyrosine at the -1 and +1 positions, histidine at the +1 position, and phenylalanine (F) at the +1 and +2 position is a preferred substrate of lysine acetyltransferase. Moreover, some virulence factors candidates including calmodulin and DnaK are acetylated. In conclusion, our data set may serve as an important resource for the elucidation of associations between functional protein lysine acetylation and virulence in H. capsulatum.
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Affiliation(s)
- Longxiang Xie
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing, China
| | - Wenjie Fang
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Wanyan Deng
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing, China
| | - Zhaoxiao Yu
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing, China
| | - Juan Li
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Min Chen
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Wanqing Liao
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China
| | - Jianping Xie
- Institute of Modern Biopharmaceuticals, State Key Laboratory Breeding Base of Eco-Environment and Bio-Resource of the Three Gorges Area, Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, School of Life Sciences, Southwest University, Beibei, Chongqing, China.
| | - Weihua Pan
- Shanghai Key Laboratory of Molecular Medical Mycology, Department of Dermatology, Changzheng Hospital, Second Military Medical University, Shanghai, China.
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15
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Spetale FE, Tapia E, Krsticevic F, Roda F, Bulacio P. A Factor Graph Approach to Automated GO Annotation. PLoS One 2016; 11:e0146986. [PMID: 26771463 PMCID: PMC4714749 DOI: 10.1371/journal.pone.0146986] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 12/23/2015] [Indexed: 12/19/2022] Open
Abstract
As volume of genomic data grows, computational methods become essential for providing a first glimpse onto gene annotations. Automated Gene Ontology (GO) annotation methods based on hierarchical ensemble classification techniques are particularly interesting when interpretability of annotation results is a main concern. In these methods, raw GO-term predictions computed by base binary classifiers are leveraged by checking the consistency of predefined GO relationships. Both formal leveraging strategies, with main focus on annotation precision, and heuristic alternatives, with main focus on scalability issues, have been described in literature. In this contribution, a factor graph approach to the hierarchical ensemble formulation of the automated GO annotation problem is presented. In this formal framework, a core factor graph is first built based on the GO structure and then enriched to take into account the noisy nature of GO-term predictions. Hence, starting from raw GO-term predictions, an iterative message passing algorithm between nodes of the factor graph is used to compute marginal probabilities of target GO-terms. Evaluations on Saccharomyces cerevisiae, Arabidopsis thaliana and Drosophila melanogaster protein sequences from the GO Molecular Function domain showed significant improvements over competing approaches, even when protein sequences were naively characterized by their physicochemical and secondary structure properties or when loose noisy annotation datasets were considered. Based on these promising results and using Arabidopsis thaliana annotation data, we extend our approach to the identification of most promising molecular function annotations for a set of proteins of unknown function in Solanum lycopersicum.
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Affiliation(s)
- Flavio E. Spetale
- CIFASIS-Conicet Institute, Rosario, Argentina
- Facultad de Cs. Exactas, Ingeniería y Agrimensura, National University of Rosario, Rosario, Argentina
| | - Elizabeth Tapia
- CIFASIS-Conicet Institute, Rosario, Argentina
- Facultad de Cs. Exactas, Ingeniería y Agrimensura, National University of Rosario, Rosario, Argentina
| | - Flavia Krsticevic
- CIFASIS-Conicet Institute, Rosario, Argentina
- Facultad Regional San Nicolás, National Technological University, San Nicolás, Argentina
| | | | - Pilar Bulacio
- CIFASIS-Conicet Institute, Rosario, Argentina
- Facultad de Cs. Exactas, Ingeniería y Agrimensura, National University of Rosario, Rosario, Argentina
- Facultad Regional San Nicolás, National Technological University, San Nicolás, Argentina
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16
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Kang CH, Lee SY, Park JH, Lee Y, Jung HS, Chi YH, Jung YJ, Chae HB, Shin MR, Kim WY, Yun D, Lee SY. Stress‐driven structural and functional switching of Ypt1p from a GTPase to a molecular chaperone mediates thermo tolerance in
Saccharomyces cerevisiae. FASEB J 2015; 29:4424-34. [DOI: 10.1096/fj.15-270140] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 06/30/2015] [Indexed: 11/11/2022]
Affiliation(s)
- Chang Ho Kang
- Division of Applied Life Science and Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuSouth Korea
| | - Sun Yong Lee
- Division of Applied Life Science and Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuSouth Korea
| | - Joung Hun Park
- Division of Applied Life Science and Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuSouth Korea
| | - Yuno Lee
- Division of Applied Life Science and Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuSouth Korea
| | - Hyun Suk Jung
- Division of Electron Microscopic ResearchKorea Basic Science InstituteDaejeonSouth Korea
- Department of BiochemistryCollege of Natural Sciences, Kangwon National UniversityChuncheonSouth Korea
| | - Yong Hun Chi
- Division of Applied Life Science and Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuSouth Korea
| | - Young Jun Jung
- Division of Applied Life Science and Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuSouth Korea
| | - Ho Byoung Chae
- Division of Applied Life Science and Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuSouth Korea
| | - Mi Rim Shin
- Division of Applied Life Science and Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuSouth Korea
| | - Woe Yeon Kim
- Division of Applied Life Science and Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuSouth Korea
| | - Dae‐Jin Yun
- Division of Applied Life Science and Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuSouth Korea
| | - Sang Yeol Lee
- Division of Applied Life Science and Plant Molecular Biology and Biotechnology Research CenterGyeongsang National UniversityJinjuSouth Korea
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17
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Abstract
Reversible protein phosphorylation is an essential posttranslational modification mechanism executed by opposing actions of protein phosphatases and protein kinases. About 1,000 predicted kinases in Arabidopsis thaliana kinome predominate the number of protein phosphatases, of which there are only ~150 members in Arabidopsis. Protein phosphatases were often referred to as "housekeeping" enzymes, which act to keep eukaryotic systems in balance by counteracting the activity of protein kinases. However, recent investigations reveal the crucial and specific regulatory functions of phosphatases in cell signaling. Phosphatases operate in a coordinated manner with the protein kinases, to execute their important function in determining the cellular response to a physiological stimulus. Closer examination has established high specificity of phosphatases in substrate recognition and important roles in plant signaling pathways, such as pathogen defense and stress regulation, light and hormonal signaling, cell cycle and differentiation, metabolism, and plant growth. In this minireview we provide a compact overview about Arabidopsis protein phosphatase families, as well as members of phosphoglucan and lipid phosphatases, and highlight the recent discoveries in phosphatase research.
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Affiliation(s)
- Alois Schweighofer
- Institute of Biotechnology, University of Vilnius, V. Graičiūno 8, 02241, Vilnius, Lithuania,
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18
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Lavania D, Dhingra A, Siddiqui MH, Al-Whaibi MH, Grover A. Current status of the production of high temperature tolerant transgenic crops for cultivation in warmer climates. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2015; 86:100-108. [PMID: 25438142 DOI: 10.1016/j.plaphy.2014.11.019] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 11/20/2014] [Indexed: 05/19/2023]
Abstract
Climate change is resulting in heightened incidences of plant heat stress episodes. Production of transgenic crops with enhanced heat stress tolerance is a highly desired agronomic trait for the sustainability of food production in 21st century. We review the current status of our understanding of the high temperature stress response of plants. We specifically deliberate on the progress made in altering levels of heat shock proteins (Hsp100, Hsp70/Hsp40 and sHsps), heat shock factors and specific metabolic proteins in improving plant tolerance to heat stress by transgenic approach.
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Affiliation(s)
- Dhruv Lavania
- Department of Plant Molecular Biology, University of Delhi, South Campus, New Delhi 110021, India.
| | - Anuradha Dhingra
- Department of Plant Molecular Biology, University of Delhi, South Campus, New Delhi 110021, India.
| | - Manzer H Siddiqui
- Department of Botany and Microbiology, King Saud University, Riyadh, Saudi Arabia.
| | - Mohamed H Al-Whaibi
- Department of Botany and Microbiology, King Saud University, Riyadh, Saudi Arabia.
| | - Anil Grover
- Department of Plant Molecular Biology, University of Delhi, South Campus, New Delhi 110021, India.
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19
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Li K, Jiang T, Yu B, Wang L, Gao C, Ma C, Xu P, Ma Y. Escherichia coli transcription termination factor NusA: heat-induced oligomerization and chaperone activity. Sci Rep 2014; 3:2347. [PMID: 23907089 PMCID: PMC3731644 DOI: 10.1038/srep02347] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 07/17/2013] [Indexed: 01/02/2023] Open
Abstract
Escherichia coli NusA, an essential component of the RNA polymerase elongation complex, is involved in transcriptional elongation, termination, anti-termination, cold shock and stress-induced mutagenesis. In this study, we demonstrated that NusA can self-assemble into oligomers under heat shock conditions and that this property is largely determined by the C-terminal domain. In parallel with the self-assembly process, NusA also acquires chaperone activity. Furthermore, NusA overexpression results in the enhanced heat shock resistance of host cells, which may be due to the chaperone activity of NusA. Our results suggest that E. coli NusA can act as a protector to prevent protein aggregation under heat stress conditions in vitro and in the NusA-overexpressing strain. We propose a new hypothesis that NusA could serve as a molecular chaperone in addition to its functions as a transcription factor. However, it remains to be further investigated whether NusA has the same function under normal physiological conditions.
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Affiliation(s)
- Kun Li
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Science, Beijing 100101, People's Republic of China
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20
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Cha JY, Ahn G, Kim JY, Kang SB, Kim MR, Su'udi M, Kim WY, Son D. Structural and functional differences of cytosolic 90-kDa heat-shock proteins (Hsp90s) in Arabidopsis thaliana. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2013; 70:368-373. [PMID: 23827697 DOI: 10.1016/j.plaphy.2013.05.039] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 05/20/2013] [Indexed: 06/02/2023]
Abstract
The seven members of the 90-kDa heat shock protein (Hsp90) family encode highly conserved molecular chaperones essential for cell survival in Arabidopsis thaliana. Hsp90 are abundant proteins, localized in different compartments with AtHsp90.1-4 in the cytosol and AtHsp90.5-7 in different organelles. Among the AtHsp90, AtHsp90.1, is stress-inducible and shares comparatively low sequence identity with the constitutively expressed AtHsp90.2-4. Even though abundant information is available on mammalian cytosolic Hsp90 proteins, it is unknown whether cytosolic Hsp90 proteins display different structural and functional properties. We have now analyzed two A. thalianas cytosolic Hsp90s, AtHsp90.1 and AtHsp90.3, for functional divergence. AtHsp90.3 showed higher holdase chaperone activity than AtHsp90.1, although both AtHsp90s exhibited effective chaperone activity. Size-exclusion chromatography revealed different oligomeric states distinguishing the two Hsp90 proteins. While AtHsp90.1 exists in several oligomeric states, including monomers, dimers and higher oligomers, AtHsp90.3 exists predominantly in a high oligomeric state. High oligomeric state of AtHsp90.1 showed higher holdase chaperone activity than the respective monomer or dimer states. When high oligomeric forms of AtHsp90.1 and AtHsp90.3 are reduced by DTT, activity was reduced compared to that found in the native high oligomeric state. In addition, ATP-dependent foldase chaperone activity of AtHsp90.3 was higher with strong intrinsic ATPase activity than that of AtHsp90.1. As a conclusion, the two A. thaliana cytosolic Hsp90 proteins display different functional activities depending on structural differences, implying functional divergence although the proteins are localized to the same sub-cellular organelle.
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Affiliation(s)
- Joon-Yung Cha
- Division of Applied Life Science (BK21 and WCU Program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-701, Republic of Korea
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21
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Uhrig RG, Labandera AM, Moorhead GB. Arabidopsis PPP family of serine/threonine protein phosphatases: many targets but few engines. TRENDS IN PLANT SCIENCE 2013; 18:505-13. [PMID: 23790269 DOI: 10.1016/j.tplants.2013.05.004] [Citation(s) in RCA: 110] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/14/2013] [Accepted: 05/17/2013] [Indexed: 05/20/2023]
Abstract
The major plant serine/threonine protein phosphatases belong to the phosphoprotein phosphatase (PPP) family. Over the past few years the complement of Arabidopsis thaliana PPP family of catalytic subunits has been cataloged and many regulatory subunits identified. Specific roles for PPPs have been characterized, including roles in auxin and brassinosteroid signaling, in phototropism, in regulating the target of rapamycin pathway, and in cell stress responses. In this review, we provide a framework for understanding the PPP family by exploring the fundamental role of the phosphatase regulatory subunits that drive catalytic engine specificity. Although there are fewer plant protein phosphatases compared with their protein kinase partners, their function is now recognized to be as dynamic and as regulated as that of protein kinases.
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Affiliation(s)
- R Glen Uhrig
- Department of Biological Sciences, University of Calgary, Canada
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22
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Choi D, Ryu KS, Park C. Structural alteration of Escherichia coli Hsp31 by thermal unfolding increases chaperone activity. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012. [PMID: 23202248 DOI: 10.1016/j.bbapap.2012.11.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Escherichia coli Hsp31, encoded by hchA, is a heat-inducible molecular chaperone. We found that Hsp31 undergoes a conformational change via temperature-induced unfolding, generating a high molecular weight (HMW) form with enhanced chaperone activity. Although it has previously been reported that some subunits of the Hsp31 crystal structure show structural heterogeneity with increased hydrophobic surfaces, Hsp31 basically forms a dimer. We found that a C-terminal deletion (CΔ19) of Hsp31 exhibited structurally and functionally similar characteristics to that of the HMW form. Both the CΔ19 and HMW forms achieved a structure with considerably more β-sheets and less α-helices than the native dimeric form, exposing a portion of its hydrophobic surfaces. The structural alterations were determined from its spectral changes in circular dichroism, intrinsic fluorescence of tryptophan residues, and fluorescence of bis-ANS binding to a hydrophobic surface. Interestingly, during thermal transition, the dimeric Hsp31 undergoes a conformational change to the HMW species via the CΔ19 structure, as monitored with near-UV CD spectrum, implying that the CΔ19 resembles an intermediate state between the dimer and the HMW form. From these results, we propose that Hsp31 transforms itself into a fully functional chaperone by altering its tertiary and quaternary structures.
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Affiliation(s)
- Dongwook Choi
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Gwahangno 335, Yuseong-Gu, Daejon 305-701, South Korea
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23
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Yeh CH, Kaplinsky NJ, Hu C, Charng YY. Some like it hot, some like it warm: phenotyping to explore thermotolerance diversity. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2012; 195:10-23. [PMID: 22920995 PMCID: PMC3430125 DOI: 10.1016/j.plantsci.2012.06.004] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2012] [Revised: 06/07/2012] [Accepted: 06/07/2012] [Indexed: 05/18/2023]
Abstract
Plants have evolved overlapping but distinct cellular responses to different aspects of high temperature stress. These responses include basal thermotolerance, short- and long-term acquired thermotolerance, and thermotolerance to moderately high temperatures. This 'thermotolerance diversity' means that multiple phenotypic assays are essential for fully describing the functions of genes involved in heat stress responses. A large number of genes with potential roles in heat stress responses have been identified using genetic screens and genome wide expression studies. We examine the range of phenotypic assays that have been used to characterize thermotolerance phenotypes in both Arabidopsis and crop plants. Three major variables differentiate thermotolerance assays: (1) the heat stress regime used, (2) the developmental stage of the plants being studied, and (3) the actual phenotype which is scored. Consideration of these variables will be essential for deepening our understanding of the molecular genetics of plant thermotolerance.
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Affiliation(s)
- Ching-Hui Yeh
- Department of Life Sciences, National Central University, Taiwan 32001, ROC
| | | | - Catherine Hu
- Agricultural Biotechnology Research Center, Academia Sinica, Taiwan 11529, ROC
| | - Yee-yung Charng
- Agricultural Biotechnology Research Center, Academia Sinica, Taiwan 11529, ROC
- Corresponding author: ; FAX: 886-2-26515600
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