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Yue Y, Deng J, Wang H, Lv T, Dou W, Jiao Y, Peng X, Zhang Y. Two Secretory T2 RNases Act as Cytotoxic Factors Contributing to the Virulence of an Insect Fungal Pathogen. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:7069-7081. [PMID: 37122240 DOI: 10.1021/acs.jafc.3c01617] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
RNase T2 members are secreted by several pathogens or parasites during infection, playing various roles in pathogen-host interaction. However, functions of those members in biocontrol microbes targeting their hosts are still unknown. Here, we report that an insect fungal pathogen, Beauveria bassiana, produces two secretory RNase T2 members that act as cytotoxic factors, which were examined by insect bioassays using the targeted gene(s) disruption and overexpression strains. Overexpression strains displayed dramatically increased virulence, which was concurrent with few fungal cells and hemocytes in hemocoel, suggesting a cytotoxicity of the overexpressed gene products. In vitro assays using yeast-expressed proteins verified the cytotoxicity of the two members against insect cells, to which the cytotoxic effect was dependent on their RNases enzyme activities and glycosylation modification. Moreover, the excessive humoral immune responses triggered by the two ribonucleases were examined. These results suggested prospects of these two T2 ribonucleases for improvement of biocontrol agents.
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Affiliation(s)
- Yong Yue
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Juan Deng
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Huifang Wang
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Ting Lv
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Wei Dou
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Yufei Jiao
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Xinxin Peng
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
| | - Yongjun Zhang
- Key Laboratory of Agricultural Biosafety and Green Production of Upper Yangtze River (Ministry of Education), Biotechnology Research Center, Southwest University, Chongqing 400715, People's Republic of China
- Key Laboratory of Entomology and Pest Control Engineering, College of Plant Protection, Southwest University, Southwest University, Chongqing 400715, People's Republic of China
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Thompson CE, Brisolara-Corrêa L, Thompson HN, Stassen H, de Freitas LB. Evolutionary and structural aspects of Solanaceae RNases T2. Genet Mol Biol 2022; 46:e20220115. [PMID: 36534953 PMCID: PMC9762611 DOI: 10.1590/1678-4685-gmb-2022-0115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 10/20/2022] [Indexed: 12/23/2022] Open
Abstract
Plant RNases T2 are involved in several physiological and developmental processes, including inorganic phosphate starvation, senescence, wounding, defense against pathogens, and the self-incompatibility system. Solanaceae RNases form three main clades, one composed exclusively of S-RNases and two that include S-like RNases. We identified several positively selected amino acids located in highly flexible regions of these molecules, mainly close to the B1 and B2 substrate-binding sites in S-like RNases and the hypervariable regions of S-RNases. These differences between S- and S-like RNases in the flexibility of amino acids in substrate-binding regions are essential to understand the RNA-binding process. For example, in the S-like RNase NT, two positively selected amino acid residues (Tyr156 and Asn134) are located at the most flexible sites on the molecular surface. RNase NT is induced in response to tobacco mosaic virus infection; these sites may thus be regions of interaction with pathogen proteins or viral RNA. Differential selective pressures acting on plant ribonucleases have increased amino acid variability and, consequently, structural differences within and among S-like RNases and S-RNases that seem to be essential for these proteins play different functions.
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Affiliation(s)
- Claudia Elizabeth Thompson
- Universidade Federal de Ciências da Saúde de Porto Alegre,
Departamento de Farmacociências, Porto Alegre, RS, Brazil
| | - Lauís Brisolara-Corrêa
- Universidade Federal do Rio Grande do Sul, Departamento de Genética,
Porto Alegre, RS, Brazil
| | - Helen Nathalia Thompson
- Universidade Federal do Rio Grande do Sul, Instituto de Química,
Departamento de Fisico-Química, Laboratório de Química Teórica e Computacional,
Porto Alegre, RS, Brazil
| | - Hubert Stassen
- Universidade Federal do Rio Grande do Sul, Instituto de Química,
Departamento de Fisico-Química, Laboratório de Química Teórica e Computacional,
Porto Alegre, RS, Brazil
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Thorn A, Steinfeld R, Ziegenbein M, Grapp M, Hsiao HH, Urlaub H, Sheldrick GM, Gärtner J, Krätzner R. Structure and activity of the only human RNase T2. Nucleic Acids Res 2012; 40:8733-42. [PMID: 22735700 PMCID: PMC3458558 DOI: 10.1093/nar/gks614] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Mutations in the gene of human RNase T2 are associated with white matter disease of the human brain. Although brain abnormalities (bilateral temporal lobe cysts and multifocal white matter lesions) and clinical symptoms (psychomotor impairments, spasticity and epilepsy) are well characterized, the pathomechanism of RNase T2 deficiency remains unclear. RNase T2 is the only member of the Rh/T2/S family of acidic hydrolases in humans. In recent years, new functions such as tumor suppressing properties of RNase T2 have been reported that are independent of its catalytic activity. We determined the X-ray structure of human RNase T2 at 1.6 Å resolution. The α+β core fold shows high similarity to those of known T2 RNase structures from plants, while, in contrast, the external loop regions show distinct structural differences. The catalytic features of RNase T2 in presence of bivalent cations were analyzed and the structural consequences of known clinical mutations were investigated. Our data provide further insight into the function of human RNase T2 and may prove useful in understanding its mode of action independent of its enzymatic activity.
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Affiliation(s)
- Andrea Thorn
- Department of Structural Chemistry, University of Göttingen, 37075 Göttingen, Germany
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A new family of membrane electron transporters and its substrates, including a new cell envelope peroxiredoxin, reveal a broadened reductive capacity of the oxidative bacterial cell envelope. mBio 2012; 3:mBio.00291-11. [PMID: 22493033 PMCID: PMC3322552 DOI: 10.1128/mbio.00291-11] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The Escherichia coli membrane protein DsbD functions as an electron hub that dispatches electrons received from the cytoplasmic thioredoxin system to periplasmic oxidoreductases involved in protein disulfide isomerization, cytochrome c biogenesis, and sulfenic acid reduction. Here, we describe a new class of DsbD proteins, named ScsB, whose members are found in proteobacteria and Chlamydia. ScsB has a domain organization similar to that of DsbD, but its amino-terminal domain differs significantly. In DsbD, this domain directly interacts with substrates to reduce them, which suggests that ScsB acts on a different array of substrates. Using Caulobacter crescentus as a model organism, we searched for the substrates of ScsB. We discovered that ScsB provides electrons to the first peroxide reduction pathway identified in the bacterial cell envelope. The reduction pathway comprises a thioredoxin-like protein, TlpA, and a peroxiredoxin, PprX. We show that PprX is a thiol-dependent peroxidase that efficiently reduces both hydrogen peroxide and organic peroxides. Moreover, we identified two additional proteins that depend on ScsB for reduction, a peroxiredoxin-like protein, PrxL, and a novel protein disulfide isomerase, ScsC. Altogether, our results reveal that the array of proteins involved in reductive pathways in the oxidative cell envelope is significantly broader than was previously thought. Moreover, the identification of a new periplasmic peroxiredoxin indicates that in some bacteria, it is important to directly scavenge peroxides in the cell envelope even before they reach the cytoplasm. IMPORTANCE Peroxides are reactive oxygen species (ROS) that damage cellular components such as lipids, proteins, and nucleic acids. The presence of protection mechanisms against ROS is essential for cell survival. Bacteria express cytoplasmic catalases and thiol-dependent peroxidases to directly scavenge harmful peroxides. We report the identification of a peroxide reduction pathway active in the periplasm of Caulobacter crescentus, which reveals that, in some bacteria, it is important to directly scavenge peroxides in the cell envelope even before they reach the cytoplasm. The electrons required for peroxide reduction are delivered to this pathway by ScsB, a new type of membrane electron transporter. We also identified two additional likely ScsB substrates, including a novel protein disulfide isomerase. Our results reveal that the array of proteins involved in reductive pathways in the oxidative environment of the cell envelope is significantly broader than was previously thought.
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MacIntosh GC. RNase T2 Family: Enzymatic Properties, Functional Diversity, and Evolution of Ancient Ribonucleases. NUCLEIC ACIDS AND MOLECULAR BIOLOGY 2011. [DOI: 10.1007/978-3-642-21078-5_4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Luhtala N, Parker R. T2 Family ribonucleases: ancient enzymes with diverse roles. Trends Biochem Sci 2010; 35:253-9. [PMID: 20189811 DOI: 10.1016/j.tibs.2010.02.002] [Citation(s) in RCA: 173] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2009] [Revised: 02/02/2010] [Accepted: 02/03/2010] [Indexed: 01/27/2023]
Abstract
Ribonucleases of the T2 family are found in the genomes of protozoans, plants, bacteria, animals and viruses. A broad range of biological roles for these ribonucleases have been suggested, including scavenging of nucleic acids, degradation of self-RNA, serving as extra- or intracellular cytotoxins, and modulating host immune responses. Recently, RNaseT2 family members have been implicated in human pathologies such as cancer and parasitic diseases. Interestingly, certain functions of RNaseT2 family members are independent of their nuclease activity, suggesting that these proteins have additional functions. Moreover, humans lacking RNASET2 manifest a defect in neurological development, perhaps due to aberrant control of the immune system. We review the basic structure and function of RNaseT2 family members and their biological roles.
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Affiliation(s)
- Natalie Luhtala
- Cancer Biology Graduate Interdisciplinary Program, University of Arizona, Tucson, AZ 85721-0106, USA
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Rodriguez SM, Panjikar S, Van Belle K, Wyns L, Messens J, Loris R. Nonspecific base recognition mediated by water bridges and hydrophobic stacking in ribonuclease I from Escherichia coli. Protein Sci 2008; 17:681-90. [PMID: 18305191 PMCID: PMC2271172 DOI: 10.1110/ps.073420708] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2007] [Revised: 01/21/2008] [Accepted: 01/21/2008] [Indexed: 10/22/2022]
Abstract
The crystal structure of Escherichia coli ribonuclease I (EcRNase I) reveals an RNase T2-type fold consisting of a conserved core of six beta-strands and three alpha-helices. The overall architecture of the catalytic residues is very similar to the plant and fungal RNase T2 family members, but the perimeter surrounding the active site is characterized by structural elements specific for E. coli. In the structure of EcRNase I in complex with a substrate-mimicking decadeoxynucleotide d(CGCGATCGCG), we observe a cytosine bound in the B2 base binding site and mixed binding of thymine and guanine in the B1 base binding site. The active site residues His55, His133, and Glu129 interact with the phosphodiester linkage only through a set of water molecules. Residues forming the B2 base recognition site are well conserved among bacterial homologs and may generate limited base specificity. On the other hand, the B1 binding cleft acquires true base aspecificity by combining hydrophobic van der Waals contacts at its sides with a water-mediated hydrogen-bonding network at the bottom. This B1 base recognition site is highly variable among bacterial sequences and the observed interactions are unique to EcRNaseI and a few close relatives.
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Affiliation(s)
- Sergio Martinez Rodriguez
- Laboratorium voor Ultrastructuur, Vrije Universiteit Brussels, Pleinlaan 2, B-1050 Brussels, Belgium
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Kawano S, Kakuta Y, Nakashima T, Kimura M. Crystal structures of the Nicotiana glutinosa ribonuclease NT in complex with nucleoside monophosphates. J Biochem 2006; 140:375-81. [PMID: 16870673 DOI: 10.1093/jb/mvj164] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Ribonuclease NT (RNase NT), induced upon tobacco mosaic virus (TMV) infection in Nicotiana glutinosa leaves, has a broad base specificity. The crystal structures of RNase NT in complex with either 5'-AMP, 5'-GMP, or 2'-UMP were determined at 1.8 A resolutions by molecular replacement. RNase NT consists of seven helices and seven beta strands, and the structure is highly similar to that of RNase NW, a guanylic acid preferential RNase from the N. glutinosa leaves, showing root mean square deviation (rmsd) of 1.1 A over an entire length of two molecules for Calpha atoms. The complex structures revealed that Trp42, Asn44, and Trp50 are involved in interactions with bases at B1 site (primary site), whereas Gln12, Tyr17, Ser78, Leu79, and Phe89 participate in recognition of bases at B2 site (subsite). The 5'-GMP and 5'-AMP bind both B1 and B2 sites in RNase NT, while 2'-UMP predominantly binds B1 site in the complex. The nucleotide binding modes in these complexes would provide a clue to elucidation of structural basis for the broad base specificity for RNase NT.
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Affiliation(s)
- Shin Kawano
- Laboratory of Biochemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Hakozaki 6-10-1, Higashi-ku, Fukuoka 812-8581
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