Ureases as multifunctional toxic proteins: A review

Carlini, Célia R.; Ligabue-Braun, Rodrigo

doi:10.1016/j.toxicon.2015.11.020

Cited by 118 publications

(119 citation statements)

References 166 publications

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“…In addition to the N assimilatory function of urease, plant ureases appear to have defensive roles against herbivore and fungal attack (Carlini and Ligabue-Braun, 2016). In soybean, three urease isoforms have been described.…”

Section: Introductionmentioning

confidence: 99%

Effect of soybean ureases on seed germination and plant development

et al. 2017

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Urease catalyzes the hydrolysis of urea to ammonia and carbon dioxide. The ammonia (nitrogen (N) product of urease activity) is incorporated into organic compounds. Thus, urease is involved in N remobilization, as well as in primary N assimilation. Two urease isoforms have been described for soybean: the embryo-specific, encoded by the Eu1 gene, and the ubiquitous urease, encoded by Eu4. A third urease-encoding gene was recently identified, designated Eu5, which encodes the putative protein product SBU-III. The present study aimed to evaluate the contribution of soybean ureases to seed germination and plant development. Analyses were performed using Eu1/Eu4/Eu5-co-suppressed transgenic plants and mutants of the Eu1 and Eu4 urease structural genes, as well as a urease-null mutant (eu3-a) that activates neither the ubiquitous nor embryo-specific ureases. The co-suppressed plants presented a developmental delay during the first month after germination; shoots and roots were significantly smaller and lighter. Slower development was observed for the double eu1-a/eu4-a mutant and the eu3-a single mutant. The N content in transgenic plants was significantly lower than in non-transgenic plants. Among the mutants, eu3-a presented the lowest and eu1-a the highest N content. Altogether, these results indicate that increased ureolytic activity plays an important role in plant development.

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Section: Introductionmentioning

confidence: 99%

Effect of soybean ureases on seed germination and plant development

et al. 2017

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“…The growing knowledge on the non-enzymatic properties of ureases, plant proteins crucial for the conversion of urea to ammonia, has unveiled their potential as biological insecticides (Carlini and Ligabue-Braun, 2016;Stanisçuaski and Carlini, 2012). Ureases (EC 3.5.1.5, urea amidohydrolase) are nickel-dependent metalloenzymes (Dixon et al, 1975) that catalyze the conversion of urea to two molecules of ammonia and one of carbon dioxide, enhancing the rate of the uncatalyzed hydrolysis by a factor of 8×10 17 (Callahan et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Central and peripheral neurotoxicity induced by the Jack Bean Urease (JBU) in Nauphoeta cinerea cockroaches

et al. 2016

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The search for novel natural molecules with insecticide potential has become a necessity more than an alternative. Understanding the mode of action of candidate molecules is a crucial step towards the development of new bioinsecticides. The present study focused on the neurotoxicity of Canavalia ensiformis urease, a natural insecticide, in cockroaches and revealed interferences on the cholinergic, octopaminergic and GABA-ergic pathways as part of its entomotoxic mode of action.

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“…Jaburetox2Ec and jaburetox (JBTX) are the two first versions of a recombinant peptide with 91 amino acids, based on jack bean urease sequence, with a potent effect against insects, yeasts and filamentous fungi [10–12]. …”

Section: Introductionmentioning

confidence: 99%

“…The insecticidal activity of JBTX occurs at very low doses (0.01 and 0.1% w/w) when compared to other plant derived entomotoxic proteins, regardless of the route of administration, either orally or by injection into the hemocell [12]. …”

Section: Introductionmentioning

confidence: 99%

“…In insect toxicity tests, the data suggest that the β-hairpin region is not important for entomotoxicity and that the N-terminal portion of JBTX is responsible for insecticidal activity. However, the C-terminal region of the peptide, which contains the β-hairpin moiety, is likely to contribute significantly to the ability of JBTX to interact with a lipid bilayer [12, 14]. …”

Section: Introductionmentioning

confidence: 99%

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Jaburetox: update on a urease-derived peptide

Becker-Ritt

Portugal

Carlini

2017

J Venom Anim Toxins Incl Trop Dis

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Urease from Canavalia ensiformis seeds was the first enzyme ever to be crystallized, in 1926. These proteins, found in plants, bacteria and fungi, present different biological properties including catalytic hydrolysis of urea, and also enzyme-independent activities, such as induction of exocytosis, pro-inflammatory effects, neurotoxicity, antifungal and insecticidal properties. Urease is toxic to insects and fungi per se but part of this toxicity relies on an internal peptide (~11 kDa), which is released upon digestion of the protein by insect enzymes. A recombinant form of this peptide, called jaburetox (JBTX), was constructed using jbureII gene as a template. The peptide exhibits liposome disruption properties, and insecticidal and fungicidal activities. Here we review the known biological properties activities of JBTX, and comment on new ones not yet fully characterized. JBTX was able to cause mortality of Aedes aegypti larvae in a feeding assay whereas in a dose as low as of 0.1 μg it provoked death of Triatoma infestans bugs. JBTX (10−5–10−6 M) inhibits the growth of E. coli, P. aeruginosa and B. cereus after 24 h incubation. Multilamellar liposomes interacting with JBTX undergo reorganization of the membrane’s lipids as detected by small angle X-ray scattering (SAXS) studies. Encapsulating JBTX into lipid nanoparticles led to an increase of the peptide’s antifungal activity. Transgenic tobacco and sugarcane plants expressing the insecticidal peptide JBTX, showed increased resistance to attack of the insect pests Spodoptera frugiperda, Diatraea saccharalis and Telchin licus licus. Many questions remain unanswered; however, so far, JBTX has shown to be a versatile peptide that can be used against various insect and fungus species, and in new bacterial control strategies.

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Ureases as multifunctional toxic proteins: A review

Cited by 118 publications

References 166 publications

Effect of soybean ureases on seed germination and plant development

Effect of soybean ureases on seed germination and plant development

Central and peripheral neurotoxicity induced by the Jack Bean Urease (JBU) in Nauphoeta cinerea cockroaches

Jaburetox: update on a urease-derived peptide

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