Differentially Expressed Forms of 1-L- -Inositol-1-Phosphate Synthase (EC) in

Johnson, Margaret Dean; Wang, Xiaohong

doi:10.1074/jbc.271.29.17215

Cited by 49 publications

(46 citation statements)

References 36 publications

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“…The biosynthetic route begins with Ins and can be summarized as showed in Figure 1. Myo-Ins, in addition to being phosphorylated to hexakis phosphate (phytic acid) during seed maturation, plays a central role in several metabolic processes and in signal transduction in the plant cell (Johnson and Wang, 1996;Raychaudhuri and Majumder 1996;Majumder et al, 1997;Raychaudhuri et al, 1997). Thus, the free myo-Ins level may influence plant growth, development and responses to variations of environmental conditions (Munnik et al, 1998;Stevenson et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

A paramutation phenomenon is involved in the genetics of maize low phytic acid1-241 (lpa1-241) trait

et al. 2008

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So far, in maize, three classes of mutants involved in phytic acid biosynthesis have been isolated: lpa1, lpa2 and lpa3. In 2007, a gene tagging experiment performed by Shi et al. found that mutations in ZmMRP4 (multidrug resistance-associated proteins 4) gene cause lpa1 phenotype. In previous studies, we isolated and described a single recessive lpa mutation (originally named lpa241), which was allelic to the lpa1-1 mutant, and was consequently renamed lpa1-241. It showed a decrease in the expression of the myo-inositol (Ins)-3-phosphate synthase gene (mips1S). In this study, we present genetic and molecular analyses of the lpa1-241 mutation that indicate an epigenetic origin of this trait, that is, a paramutagenic interaction that results in meiotically heritable changes in ZmMRP4 gene expression, causing a strong pleiotropic effect on the whole plant. The use of a 5-Azacytidine treatment provided data suggesting an association between gene methylation and the lpa1-241 phenotype. To our knowledge, this is the first report of a paramutagenic activity not involving flavonoid biosynthesis in maize, but regarding a key enzyme of an important metabolic pathway in plants.

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Section: Introductionmentioning

confidence: 99%

A paramutation phenomenon is involved in the genetics of maize low phytic acid1-241 (lpa1-241) trait

et al. 2008

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“…Generation of free myo-inositol may be blocked if MIPP is not active. The MIPS reaction has been reported to occur in a large number of living systems namely archea (Chen et al, 2000), bacteria (Bachhawat and Mande, 2000), protozoa (Lohia et al, 1999), lower plants (Donahue and Henry, 1981a,b;Escamilla et al, 1982;Dasgupta et al, 1984;RayChoudhury et al, 1997;Benaroya et al, 2004, Chhetri et al, 2005, higher plants (Loewus and Loewus, 1971;Loewus et al, 1978;Ogunyemi et al, 1978;Adhikari et al, 1987;Johnson and Sussex, 1995;Johnson and Wang, 1996;Chun et al, 2003), and animals (Pittner and Hoffmann-Ostenhof, 1976;Maeda and Eisenberg Jr., 1980;Majumder, 1983, 1988;Chiu et al, 2003). In pteridophytes, Benaroya et al (2004) and Chettri et al (2005Chettri et al ( , 2006 have recently documented the occurrence and characterization of L-myo-inositol-1-phosphate synthase.…”

Section: Introductionmentioning

confidence: 99%

Occurrence of myo-inositol-1-phosphate phosphatase in pteridophytes: characteristics of the enzyme from the reproductive pinnules of Dryopteris filix-mas (L.) Schott

Banerjee

Chhetri²,

Adhikari

2007

Braz. J. Plant Physiol.

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Evident myo-inositol-1-phosphate phosphatase (MIPP) activity has been detected both in the vegetative as well as in the spore-bearing organs of some selected pteridophytes having wide phylogenetic diversity. The basic characterization of this enzyme was carried out using the cosmopolitan fern Dryopteris filix-mas. The enzyme was partially purified from the cytosol fraction obtained from the reproductive pinnules of the plant to about 41-fold over the initial homogenate following low-speed centrifugation, streptomycin sulfate precipitation, 25-70% ammonium sulfate fractionation, CM Sephadex C-50 chromatography and finally gel-filtration on Ultrogel AcA 34. The apparent molecular weight of the native MIPP was estimated to be 94 kDa. The enzyme activity increased linearly with respect to protein concentration to about 150 µg and with respect to time up to 75 min. The temperature optimum was found at 40ºC. However, the enzyme showed good activity over the temperature range of 30-50ºC. This enzyme used D/L-myo-inositol-1-phosphate as its principal substrate (95-100%), however, about 16% activity was recorded when D-myo-inositol-3-phosphate substituted as substrate. Furthermore, weak (3%) activity of this MIPP was observed with 2-glycerophosphate as substrate. The apparent K m for pteridophytic MIPP was 0.083 mM. The enzyme was functional in a narrow pH range of 7.5 to 8.5. The activity of this MIPP enzyme was remarkably inhibited by the presence of a monovalent cation, lithium, and even moderately so at a low concentration such as 1 mM. On the other hand, magnesium, a divalent cation, enhanced activity at least up to 10 mM. Calcium diminished MIPP activity at concentrations over 4 mM. Key words: Dryopteris filix-mas, myo-inositol-1-phosphate phosphatase, pteridophytes, reproductive pinnulesOcorrência da fosfatase do mio-inositol-1-fosfato em pteridófitas: características da enzima a partir de pínulas reprodutivas de Dryopteris filix-mas (L.) Schott: Tem-se detectado atividade da fosfatase do mio-inositol-1-fosfato (FMIF) tanto em órgãos vegetativos como em estruturas esporulantes de algumas pteridófitas com ampla diversidade filogenética. Neste estudo, procedeu-se à caracterização básica dessa enzima utilizando-se da pteridófita cosmopolita Dryopteris filix-mas. Após centrifugação em baixa velocidade, precipitação com sulfato de estreptomicina, fracionamento com sulfato de amônio (25-70%), cromatografia em CM Sephadex C-50 e, finalmente, filtração gélica em Ultrogel AcA 34, conseguiu-se uma purificação parcial da enzima (a partir da fração citossólica obtida de pínulas reprodutivas da planta) de cerca de 41 vezes em relação ao homogenato inicial. O peso molecular aparente da FMIF nativa foi estimado em 94 kDa. A atividade da enzima aumentou linearmente com relação ao conteúdo de proteína (cerca de 150 µg) e com relação ao tempo (até 75 min). A temperatura ótima foi de 40ºC. Entretanto, a enzima exibiu atividade razoável na faixa de temperatura entre 30 e 50ºC. O D/L-mio-inositol-1-fosfato foi o principal substrato (9...

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“…It is formed by the conversion of DGlucose-6-Phosphate (G-6-P) to L-myo-inositol-1-phosphate (I-1-P) by the enzyme L-myo-inositol-1-phosphate synthase (MIPS; EC: 5.5.1.4) and is subsequently dephosphorylated by inositol monophosphatase (EC: 3.1.3.25) to myo-inositol (Lohia et al, 1999). The MIPS reaction has been reported for archea (Chen et al, 2000), bacteria (Bachhawat and Mande, 1999;, protozoa (Lohia et al, 1999), lower plants (Donahue and Henry, 1981a;1981b;Escamilla et al, 1982;Dasgupta et al, 1984;RayChoudhury et al, 1997;Benaroya et al, 2004;Chhetri et al, 2005), higher plants (Loewus and Loewus, 1971;Loewus et al, 1978;Ogunyemi et al, 1978;Adhikari and Majumder, 1983;Johnson and Sussex, 1995;Johnson and Wang, 1996;Chun et al, 2003) and animals (Pittner and Hoffmann-Ostenhof, 1976;1979;Maeda and Eisenberg Jr., 1980;Adhikari and Majumder, 1988;Chiu et al, 2003). The present study reports the occurrences of free myo-inositol in different pteridophytes.…”

Section: Introductionmentioning

confidence: 99%

Myo-inositol content in pteridophytes and the isolation and characterization of L-myo-inositol-1-phosphate synthase from Diplopterygium glaucum

Chhetri¹,

Mukherjee

Adhikari

2006

Braz. J. Plant Physiol.

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Myo-inositol is involved in normal growth and development of all living organisms and L-myo-inositol-1-phosphate synthase (MIPS; EC: 5.5.1.4) is responsible for its de novo synthesis. This enzyme has been reported for a number of life forms including plants, animals and bacteria. In the present study free myo-inositol has been detected in the common pteridophytes found in the Darjeeling Himalayas and the enzyme, L-myo-inositol-1-phosphate synthase has been partially purified from Diplopterygium glaucum (Thunb.) Nakai. A crude homogenate from the reproductive pinnules of D. glaucum was subjected to streptomycin sulphate precipitation and 0-70% ammonium sulphate fractionation followed by successive chromatography through DEAEcellulose, Hexylagarose and BioGel A-0.5m columns. This resulted in a partial purification of the enzyme of about 81-fold with 13.5% recovery. The pteridophytic MIPS specifically utilized D-glucose-6-phosphte and NAD + as its substrate and co-factor, respectively. It shows a pH optimum between 7.0 and 7.5 while the temperature maximum was 30 °C. The enzyme activity was stimulated by NH 4 + , slightly inhibited by Na + , Ba 2+ and Cd 2+ , and strongly inhibited by Li + , Zn 2+ and Hg 2+ . EDTA, pCMB and some substrate isomers like glucose-1-phosphate, fructose-6-phosphte and galactose-6-phosphate were inhibitory to the enzyme. The apparent molecular weight of the native D. glaucum MIPS was determined to be approximately 171 kDa. Key words: D-glucose-6-phosphate, Gleicheniaceae, inositol synthase, myo-inositol. Conteúdo de myo-inositol em pteridófitas e o isolamento e caracterização da sintase de L-myo-inositol-1-fosfato de Diplopterygium glaucum:Myo-inositol está envolvido no crescimento e desenvolvimento de todos os organismos vivos e a enzima sintase do L-myo-inositol-1-fosfato (MIPS; EC: 5.5.1.4) é responsável pela sua síntese de novo. Esta enzima tem sido relatada em um número grande de plantas, animais e bactérias. No presente estudo myo-inositol não complexado foi detectado em pteridófitas comuns encontradas em Darjeeling Himalayas e a enzima sintase do L-myo-inositol-1-fosfato foi parcialmente purificada a partir de Diplopterygium glaucum (Thunb.) Nakai. Um extrato protéico não purificado de pinulas reprodutivas foi precipitada com sulfato de estreptomicina e 0-70% sulfato de amônia seguido de sucessivas cromatografias em colunas de DEAE-celulose, Hexylagarose e BioGel A. Este procedimento resultou na purificação parcial de 81 vezes, com recuperação de 13.5%. A MIPS dessa pteridófita usou especificamente D-glicose-6-fosfato and NAD + como substrato e cofator, respectivamente. Mostrou pH ótimo entre 7,0 e 7,5, enquanto a temperatura ótima foi 30°C. A atividade da enzima foi estimulada por NH 4 + , pouco inibida por Na + , Ba 2+ e Cd 2+ , e fortemente inibida por Li + , Zn 2+ e Hg 2+ . EDTA, pCMB e alguns substratos isôme-ros, como glicose-1-fosfato, frutose-6-fosfato e galactose-6-fosfato inibiram a enzima. A massa molecular aparente da MIPS de D. glaucum é aproximadamente 171 kDa. Palavr...

show abstract

Differentially Expressed Forms of 1-L- -Inositol-1-Phosphate Synthase (EC) in

Cited by 49 publications

References 36 publications

A paramutation phenomenon is involved in the genetics of maize low phytic acid1-241 (lpa1-241) trait

A paramutation phenomenon is involved in the genetics of maize low phytic acid1-241 (lpa1-241) trait

Occurrence of myo-inositol-1-phosphate phosphatase in pteridophytes: characteristics of the enzyme from the reproductive pinnules of Dryopteris filix-mas (L.) Schott

Myo-inositol content in pteridophytes and the isolation and characterization of L-myo-inositol-1-phosphate synthase from Diplopterygium glaucum

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