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Comparative molecular biological analysis of membrane transport genes in organisms.

Nagata T, Iizumi S, Satoh K, Kikuchi S - Plant Mol. Biol. (2008)

Bottom Line: Plants use H(+) ions pooled in vacuoles and the apoplast to transport various substances; these proton gradients are also dependent on secondary active transporters.We also compared the numbers of membrane transporter genes in Arabidopsis and rice.Although many transporter genes are similar in these plants, Arabidopsis has a more diverse array of genes for multi-efflux transport and for response to stress signals, and rice has more secondary transporter genes for carbohydrate and nutrient transport.

View Article: PubMed Central - PubMed

Affiliation: Plant Genome Research Unit, Division of Genome and Biodiversity Research, National Institute of Agrobiological Sciences, Kannondai 2-1-2, Tsukuba, Ibaraki 305-8602, Japan.

ABSTRACT
Comparative analyses of membrane transport genes revealed many differences in the features of transport homeostasis in eight diverse organisms, ranging from bacteria to animals and plants. In bacteria, membrane-transport systems depend mainly on single genes encoding proteins involved in an ATP-dependent pump and secondary transport proteins that use H(+) as a co-transport molecule. Animals are especially divergent in their channel genes, and plants have larger numbers of P-type ATPase and secondary active transporters than do other organisms. The secondary transporter genes have diverged evolutionarily in both animals and plants for different co-transporter molecules. Animals use Na(+) ions for the formation of concentration gradients across plasma membranes, dependent on secondary active transporters and on membrane voltages that in turn are dependent on ion transport regulation systems. Plants use H(+) ions pooled in vacuoles and the apoplast to transport various substances; these proton gradients are also dependent on secondary active transporters. We also compared the numbers of membrane transporter genes in Arabidopsis and rice. Although many transporter genes are similar in these plants, Arabidopsis has a more diverse array of genes for multi-efflux transport and for response to stress signals, and rice has more secondary transporter genes for carbohydrate and nutrient transport.

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Comparison of numbers of pump genes among various organisms. Pump gene numbers were compared among Escherichia coli K12-MG1655, Arabidopsis thaliana, Oryza sativa, Caenorhabditis elegans, Drosophila melanogaster, Homo sapiens NCBI, Neurospora crassa 74-OR23-IVA, and Saccharomyces cerevisiae S228C. ABC: ATP-binding Cassette; ArsAB: Arsenite-antimonite Efflux; F-ATPase: H+ or Na+-translocating F-type, V-type and A-type ATPase; H+-Ppase: H+-translocating Pyrophosphatase; IISP: General Secretory Pathway (Sec); MPT: Mitochondrial Protein Translocase; P-ATPase: P-type ATPase
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Fig2: Comparison of numbers of pump genes among various organisms. Pump gene numbers were compared among Escherichia coli K12-MG1655, Arabidopsis thaliana, Oryza sativa, Caenorhabditis elegans, Drosophila melanogaster, Homo sapiens NCBI, Neurospora crassa 74-OR23-IVA, and Saccharomyces cerevisiae S228C. ABC: ATP-binding Cassette; ArsAB: Arsenite-antimonite Efflux; F-ATPase: H+ or Na+-translocating F-type, V-type and A-type ATPase; H+-Ppase: H+-translocating Pyrophosphatase; IISP: General Secretory Pathway (Sec); MPT: Mitochondrial Protein Translocase; P-ATPase: P-type ATPase

Mentions: We compared the ATP-dependent transport genes in this diverse set of organisms (Table 1, Fig. 2, and Supplemental data-2). The main roles of the ATP-dependent (pump) proteins are (1) to transport molecules in specific directions independently of the environmental situation; and (2) to transport ions to form a concentration gradient between the areas outside and inside the membrane (active transport). Because bacteria cannot control the concentrations of ions or metabolites outside the cell, their pumps work mainly to transport molecules. In E. coli, most of the ATP-dependent genes (93%) encode ATP-binding cassette (ABC) proteins, and some of them are reported to encode channel proteins (Fig. 2, Table 1) (Holland et al. 2005). The ABC proteins transport various substances (e.g. ions, peptides, nucleosides, amino acids, carbohydrates, proteins) ATP-dependently in all organisms (Kolukisaoglu et al. 2002; Garcia et al. 2004). In eukaryotes, many functional units are present within one polypeptide, whereas many bacterial ABC subunits are encoded by individual genes. This results in an inverted relationship between prokaryotes (E. coli) (72) and primitive eukaryotes (yeast) (43). Many bacterial ABC proteins are located in the plasma membrane and serve as the main forces in energy-consuming transport for both import and export of substances. In higher eukaryotes, ABC proteins tend to export substances rather than function in import reactions.Fig. 2


Comparative molecular biological analysis of membrane transport genes in organisms.

Nagata T, Iizumi S, Satoh K, Kikuchi S - Plant Mol. Biol. (2008)

Comparison of numbers of pump genes among various organisms. Pump gene numbers were compared among Escherichia coli K12-MG1655, Arabidopsis thaliana, Oryza sativa, Caenorhabditis elegans, Drosophila melanogaster, Homo sapiens NCBI, Neurospora crassa 74-OR23-IVA, and Saccharomyces cerevisiae S228C. ABC: ATP-binding Cassette; ArsAB: Arsenite-antimonite Efflux; F-ATPase: H+ or Na+-translocating F-type, V-type and A-type ATPase; H+-Ppase: H+-translocating Pyrophosphatase; IISP: General Secretory Pathway (Sec); MPT: Mitochondrial Protein Translocase; P-ATPase: P-type ATPase
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2268718&req=5

Fig2: Comparison of numbers of pump genes among various organisms. Pump gene numbers were compared among Escherichia coli K12-MG1655, Arabidopsis thaliana, Oryza sativa, Caenorhabditis elegans, Drosophila melanogaster, Homo sapiens NCBI, Neurospora crassa 74-OR23-IVA, and Saccharomyces cerevisiae S228C. ABC: ATP-binding Cassette; ArsAB: Arsenite-antimonite Efflux; F-ATPase: H+ or Na+-translocating F-type, V-type and A-type ATPase; H+-Ppase: H+-translocating Pyrophosphatase; IISP: General Secretory Pathway (Sec); MPT: Mitochondrial Protein Translocase; P-ATPase: P-type ATPase
Mentions: We compared the ATP-dependent transport genes in this diverse set of organisms (Table 1, Fig. 2, and Supplemental data-2). The main roles of the ATP-dependent (pump) proteins are (1) to transport molecules in specific directions independently of the environmental situation; and (2) to transport ions to form a concentration gradient between the areas outside and inside the membrane (active transport). Because bacteria cannot control the concentrations of ions or metabolites outside the cell, their pumps work mainly to transport molecules. In E. coli, most of the ATP-dependent genes (93%) encode ATP-binding cassette (ABC) proteins, and some of them are reported to encode channel proteins (Fig. 2, Table 1) (Holland et al. 2005). The ABC proteins transport various substances (e.g. ions, peptides, nucleosides, amino acids, carbohydrates, proteins) ATP-dependently in all organisms (Kolukisaoglu et al. 2002; Garcia et al. 2004). In eukaryotes, many functional units are present within one polypeptide, whereas many bacterial ABC subunits are encoded by individual genes. This results in an inverted relationship between prokaryotes (E. coli) (72) and primitive eukaryotes (yeast) (43). Many bacterial ABC proteins are located in the plasma membrane and serve as the main forces in energy-consuming transport for both import and export of substances. In higher eukaryotes, ABC proteins tend to export substances rather than function in import reactions.Fig. 2

Bottom Line: Plants use H(+) ions pooled in vacuoles and the apoplast to transport various substances; these proton gradients are also dependent on secondary active transporters.We also compared the numbers of membrane transporter genes in Arabidopsis and rice.Although many transporter genes are similar in these plants, Arabidopsis has a more diverse array of genes for multi-efflux transport and for response to stress signals, and rice has more secondary transporter genes for carbohydrate and nutrient transport.

View Article: PubMed Central - PubMed

Affiliation: Plant Genome Research Unit, Division of Genome and Biodiversity Research, National Institute of Agrobiological Sciences, Kannondai 2-1-2, Tsukuba, Ibaraki 305-8602, Japan.

ABSTRACT
Comparative analyses of membrane transport genes revealed many differences in the features of transport homeostasis in eight diverse organisms, ranging from bacteria to animals and plants. In bacteria, membrane-transport systems depend mainly on single genes encoding proteins involved in an ATP-dependent pump and secondary transport proteins that use H(+) as a co-transport molecule. Animals are especially divergent in their channel genes, and plants have larger numbers of P-type ATPase and secondary active transporters than do other organisms. The secondary transporter genes have diverged evolutionarily in both animals and plants for different co-transporter molecules. Animals use Na(+) ions for the formation of concentration gradients across plasma membranes, dependent on secondary active transporters and on membrane voltages that in turn are dependent on ion transport regulation systems. Plants use H(+) ions pooled in vacuoles and the apoplast to transport various substances; these proton gradients are also dependent on secondary active transporters. We also compared the numbers of membrane transporter genes in Arabidopsis and rice. Although many transporter genes are similar in these plants, Arabidopsis has a more diverse array of genes for multi-efflux transport and for response to stress signals, and rice has more secondary transporter genes for carbohydrate and nutrient transport.

Show MeSH
Related in: MedlinePlus