RESUMO
Background: Ornithine decarboxylase antizyme 1 (OAZ1) is an important regulator of polyamine synthesis and uptake. Our previous studies indicated that high OAZ1 expression in the ovaries of laying geese is responsible for poor egg production. In the present study, the molecular characterization of goose OAZ1 gene was analyzed, as well as the expression profile in various follicular tissues. Results: An 873-bp cDNA sequence of the OAZ1 gene (Accession No. KC845302) with a +1 frameshift site (+175T) was obtained. The sequence consisted of a 652-bp two overlapping open reading frames (a putative protein with 216 amino acids). The OAZ domain, OAZ signature and OAZ super family domain were prominent conserved regions among species. As the follicle size increased, OAZ1 abundance showed an increasing trend during follicular development, while it decreased during follicular regression. The level of OAZ1 mRNA expression was the lowest in the fifth largest preovulatory follicle, and was 0.65-fold compared to the small white follicle (P b 0.05). OAZ1 mRNA expression in the largest preovulatory and postovulatory follicle was 2.11- and 2.49-fold compared to the small white follicle, respectively (P b 0.05). Conclusions: The goose OAZ1 structure confirms that OAZ1 plays an important role in ornithine decarboxylase-mediated regulation of polyamine homeostasis. Our findings provide an evidence for a potential function of OAZ1 in follicular development, ovulation and regression.
Assuntos
Animais , Feminino , Proteínas/genética , Proteínas/metabolismo , Gansos/metabolismo , Folículo Ovariano/metabolismo , Ornitina Descarboxilase/metabolismo , Poliaminas/metabolismo , RNA Mensageiro , Clonagem Molecular , Análise de Sequência , DNA Complementar , Reação em Cadeia da Polimerase em Tempo Real , Folículo Ovariano/crescimento & desenvolvimentoRESUMO
The role of intracellular free polyamine (putrescine and spermidine) pools in multiple resistance to aminoglycoside antibiotics was investigated among in vitro selected kanamycin-resistant Escherichia coli J53 mutants expressing diminished oligopeptide-binding protein (OppA) levels and/or defective ornithine decarboxylase (ODC) activity. The results suggest that diminished OppA content, but not defective ODC activity expression, increased the relative concentration of free spermidine as compared to the wild type strain. Moreover, by adding exogenous polyamines or polyamine synthesis inhibitors to cultures with different mutant strains, a direct relationship between the intracellular OppA levels and resistance to kanamycin was revealed. Collectively these results further suggest a complex relation among OppA expression, aminoglycoside resistance and polyamine metabolism.
Assuntos
Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli/efeitos dos fármacos , Poliaminas/metabolismo , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Eletroforese em Gel de Poliacrilamida , Escherichia coli/enzimologia , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Immunoblotting , Ornitina Descarboxilase/metabolismo , Putrescina/metabolismo , Espermidina/metabolismoRESUMO
Level of free polyamines, their key metabolic enzymes, and other features related to ageing were examined during stipule and pod wall development in pea (Pisum sativum). Free polyamine titre (per unit fresh mass) in both the organs, the specific activities of arginine decarboxylase and ornithine decarboxylase in the pod wall, gradually decreased with maturation. In stipule, these enzymes attained peak activity at 15 days after pod emergence and declined thereafter. Ornithine decarboxylase activity was greater in pod wall than in stipule; while, arginine decarboxylase activity was higher in stipule. Activity of degradative enzyme diamine oxidase increased with the onset of senescence in both the organs. Chlorophyll and electrical conductance had a inverse relationship throughout the experimental period, whereas, the chlorophyll content was directly related with polyamine levels in both stipule and pod wall during aging. On the other hand, protein and RNA contents were positively correlated with free polyamines throughout the test period in stipule, but in the pod wall this was true only for the later stages of development.
Assuntos
Envelhecimento/fisiologia , Amina Oxidase (contendo Cobre)/metabolismo , Carboxiliases/metabolismo , Clorofila/metabolismo , DNA de Plantas/metabolismo , Condutividade Elétrica , Regulação da Expressão Gênica no Desenvolvimento , Ornitina Descarboxilase/metabolismo , Pisum sativum/enzimologia , Proteínas de Plantas/metabolismo , Poliaminas/metabolismo , Putrescina/metabolismo , RNA de Plantas/metabolismo , Espermidina/metabolismo , Espermina/metabolismoRESUMO
The effect of exposing rats to amplitude modulated radiofrequency radiation (112 MHz modulated to 16 Hz) during development and growth has been examined. Wistar rats (35 days old) when exposed at above frequency at the power level 1.0 mW/cm2 (SAR, 0.75 W/kg) for 35 days showed enhanced ornithine decarboxylase activity and Ca2+ efflux in brain indicating potential health hazards due to exposure.