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1.
Exp Parasitol ; 126(1): 91-6, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20035751

RESUMO

New more efficacious antimicrobials as required for the treatment of Acanthamoeba infections as those currently available require arduous treatment regimes, are not always effective and are poorly active against the cystic stages. Herein, we review potential drug targets including tubulin, alternative oxidase, amino acid biosynthesis and myosin. In addition, we review the literature for current missing tools and resources for the identification, validation and development of new antimicrobials for this organism. Additional targets should come to light through a concerted genome sequencing effort.


Assuntos
Acanthamoeba/efeitos dos fármacos , Amebíase/tratamento farmacológico , Antiprotozoários/farmacologia , Acanthamoeba/genética , Animais , Antiprotozoários/uso terapêutico , Celulose/antagonistas & inibidores , Proteínas do Citoesqueleto/antagonistas & inibidores , Modelos Animais de Doenças , Humanos , Proteínas Mitocondriais , Ornitina Descarboxilase/efeitos dos fármacos , Oxirredutases/efeitos dos fármacos , Proteínas de Plantas
2.
Org Biomol Chem ; 7(6): 1097-105, 2009 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-19262928

RESUMO

A series of D-glucose derivatives that have been modified at C-4 were synthesised from D-galactose as potential chain terminators of cellulose biosynthesis. Two compounds displayed herbicidal activity in pre-emergence tests and in addition a cell expansion assay at higher concentrations revealed symptomology of a third compound that was indicative of inhibition of cellulose biosynthesis.


Assuntos
Celulose/antagonistas & inibidores , Celulose/biossíntese , Glucose/síntese química , Glucose/farmacologia , Monossacarídeos/síntese química , Monossacarídeos/farmacologia , Celulose/química , Relação Dose-Resposta a Droga , Galactose/química , Glucose/análogos & derivados , Estrutura Molecular , Monossacarídeos/química , Estereoisomerismo , Nicotiana/citologia , Nicotiana/efeitos dos fármacos , Nicotiana/metabolismo
3.
J Exp Bot ; 59(14): 3963-74, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18832186

RESUMO

The co-ordination of cell wall synthesis with plant cell expansion is an important topic of contemporary plant biology research. In studies of cell wall synthesis pathways, cellulose synthesis inhibitors are broadly used. It is demonstrated here that ancymidol, known as a plant growth retardant primarily affecting gibberellin biosynthesis, is also capable of inhibiting cellulose synthesis. Its ability to inhibit cellulose synthesis is not related to its anti-gibberellin action and possesses some unique features never previously observed when conventional cellulose synthesis inhibitors were used. It is suggested that ancymidol targets the cell wall synthesis pathway at a regulatory step where cell wall synthesis and cell expansion are coupled. The elucidation of the ancymidol target in plant cells could potentially contribute to our understanding of cell wall synthesis and cell expansion control.


Assuntos
Celulose/antagonistas & inibidores , Nicotiana/citologia , Nicotiana/efeitos dos fármacos , Pirimidinas/farmacologia , Forma Celular/efeitos dos fármacos , Parede Celular/efeitos dos fármacos , Parede Celular/metabolismo , Células Cultivadas , Celulose/biossíntese , Giberelinas/antagonistas & inibidores , Giberelinas/biossíntese , Nicotiana/metabolismo
4.
Plant Physiol ; 148(3): 1283-94, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18805954

RESUMO

We have identified a gene, denoted PttMAP20, which is strongly up-regulated during secondary cell wall synthesis and tightly coregulated with the secondary wall-associated CESA genes in hybrid aspen (Populus tremula x tremuloides). Immunolocalization studies with affinity-purified antibodies specific for PttMAP20 revealed that the protein is found in all cell types in developing xylem and that it is most abundant in cells forming secondary cell walls. This PttMAP20 protein sequence contains a highly conserved TPX2 domain first identified in a microtubule-associated protein (MAP) in Xenopus laevis. Overexpression of PttMAP20 in Arabidopsis (Arabidopsis thaliana) leads to helical twisting of epidermal cells, frequently associated with MAPs. In addition, a PttMAP20-yellow fluorescent protein fusion protein expressed in tobacco (Nicotiana tabacum) leaves localizes to microtubules in leaf epidermal pavement cells. Recombinant PttMAP20 expressed in Escherichia coli also binds specifically to in vitro-assembled, taxol-stabilized bovine microtubules. Finally, the herbicide 2,6-dichlorobenzonitrile, which inhibits cellulose synthesis in plants, was found to bind specifically to PttMAP20. Together with the known function of cortical microtubules in orienting cellulose microfibrils, these observations suggest that PttMAP20 has a role in cellulose biosynthesis.


Assuntos
Parede Celular/efeitos dos fármacos , Celulose/antagonistas & inibidores , Proteínas Associadas aos Microtúbulos/efeitos dos fármacos , Nitrilas/farmacologia , Árvores/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Parede Celular/metabolismo , Celulose/sangue , Primers do DNA , Perfilação da Expressão Gênica , Hibridização Genética , Proteínas Associadas aos Microtúbulos/química , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos
5.
Appl Microbiol Biotechnol ; 75(1): 133-40, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17225099

RESUMO

Acanthamoeba is an opportunistic protozoan pathogen that can cause blinding keratitis as well as fatal granulomatous encephalitis. One of the distressing aspects in combating Acanthamoeba infections is the prolonged and problematic treatment. For example, current treatment against Acanthamoeba keratitis requires early diagnosis followed by hourly topical application of a mixture of drugs that can last up to a year. The aggressive and prolonged management is due to the ability of Acanthamoeba to rapidly adapt to harsh conditions and switch phenotypes into a resistant cyst form. One possibility of improving the treatment of Acanthamoeba infections is to inhibit the ability of these parasites to switch into the cyst form. The cyst wall is partially made of cellulose. Here, we tested whether a cellulose synthesis inhibitor, 2,6-dichlorobenzonitrile (DCB), can enhance the effects of the antiamoebic drug pentamidine isethionate (PMD). Our findings revealed that DCB can block Acanthamoeba encystment and may improve the antiamoebic effects of PMD. Using in vitro assays, the findings revealed that DCB enhanced the inhibitory effects of PMD on Acanthamoeba binding to and cytotoxicity of the host cells, suggesting the cellulose biosynthesis pathway as a novel target for the improved treatment of Acanthamoeba infections.


Assuntos
Ceratite por Acanthamoeba/tratamento farmacológico , Acanthamoeba castellanii/efeitos dos fármacos , Amebicidas/farmacologia , Celulose/biossíntese , Nitrilas/farmacologia , Pentamidina/farmacologia , Ceratite por Acanthamoeba/parasitologia , Acanthamoeba castellanii/crescimento & desenvolvimento , Acanthamoeba castellanii/isolamento & purificação , Acanthamoeba castellanii/metabolismo , Amebicidas/toxicidade , Animais , Encéfalo/irrigação sanguínea , Células Cultivadas , Celulose/antagonistas & inibidores , Sinergismo Farmacológico , Endotélio Vascular/citologia , Humanos , Microcirculação , Nitrilas/toxicidade , Pentamidina/toxicidade
6.
Plant Cell ; 14(7): 1557-66, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12119374

RESUMO

Biotic and abiotic stresses stimulate the synthesis of jasmonates and ethylene, which, in turn, induce the expression of genes involved in stress response and enhance defense responses. The cev1 mutant has constitutive expression of stress response genes and has enhanced resistance to fungal pathogens. Here, we show that cev1 plants have increased production of jasmonate and ethylene and that its phenotype is suppressed by mutations that interrupt jasmonate and ethylene signaling. Genetic mapping, complementation analysis, and sequence analysis revealed that CEV1 is the cellulose synthase CeSA3. CEV1 was expressed predominantly in root tissues, and cev1 roots contained less cellulose than wild-type roots. Significantly, the cev1 mutant phenotype could be reproduced by treating wild-type plants with cellulose biosynthesis inhibitors, and the cellulose synthase mutant rsw1 also had constitutive expression of VSP. We propose that the cell wall can signal stress responses in plants.


Assuntos
Arabidopsis/genética , Parede Celular/genética , Ciclopentanos/metabolismo , Etilenos/biossíntese , Transdução de Sinais/genética , Arabidopsis/efeitos dos fármacos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Parede Celular/efeitos dos fármacos , Celulose/antagonistas & inibidores , Celulose/biossíntese , Clonagem Molecular , Ciclopentanos/farmacologia , Escuridão , Etilenos/farmacologia , Regulação da Expressão Gênica de Plantas , Teste de Complementação Genética , Glucosiltransferases/genética , Hipocótilo/crescimento & desenvolvimento , Luz , Mutação , Oxilipinas , Fenótipo , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Caules de Planta/genética , Caules de Planta/metabolismo , Receptores de Superfície Celular/metabolismo , Mapeamento por Restrição , Estresse Mecânico
7.
Plant Cell Physiol ; 39(7): 779-85, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9729901

RESUMO

The biochemical analysis of cellulose biosynthesis by plants has been a difficult problem due to the lack of a reliable assay procedure for cellulose synthase activity. Recently, the celA1 gene was cloned from cotton fiber, and this gene was identified from the rsw1 mutant of Arabidopsis as a catalytic subunit of cellulose synthase (Arioli et al. 1998). The cloning of these genes enables us to obtain specific antibodies against cellulose synthase. A highly specific antibody against celA1 protein was prepared and used to detect the protein from microsomal fraction of tobacco BY-2 cells. The quantity of celA1 protein in microsomal fraction of normal BY-2 cells was under the detection limit, although they contained a large quantity of cellulose. In contrast, cells habituated to 1 microM DCB (a specific inhibitor of cellulose biosynthesis) produced 1/10 of cellulose content of the normal cells, but had much more celA1 protein than the normal cells. The amount of polysaccharides in the EDTA-soluble fraction was relatively increased in habituated cells. The results suggest that celA1 protein is stabilized upon DCB binding and that the crystallization of cellulose microfibrils is inhibited simultaneously.


Assuntos
Celulase/metabolismo , Celulose/antagonistas & inibidores , Nicotiana/efeitos dos fármacos , Nitrilas/farmacologia , Plantas Tóxicas , Sequência de Aminoácidos , Western Blotting , Linhagem Celular , Parede Celular/metabolismo , Celulase/química , Celulose/biossíntese , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Nicotiana/metabolismo
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