Publication:
Sodium-dependent uptake of glutamate by novel ApGltS enhanced growth under salt stress of halotolerant cyanobacterium aphanothece halophytica

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Issued Date

2012

Resource Type

Article

File Type

application/pdf

ISSN

9168451

DOI

10.1271/bbb.120309

Other identifier(s)

2-s2.0-84866649295

Rights Holder(s)

มหาวิทยาลัยศรีนครินทรวิโรฒ

Bibliographic Citation

Bioscience, Biotechnology and Biochemistry. Vol 76, No.9 (2012), p.1702-1707

Suggested Citation

Boonburapong B., Laloknam S., Yamada N., Incharoensakdi A., Takabe T. Sodium-dependent uptake of glutamate by novel ApGltS enhanced growth under salt stress of halotolerant cyanobacterium aphanothece halophytica. Bioscience, Biotechnology and Biochemistry. Vol 76, No.9 (2012), p.1702-1707. doi:10.1271/bbb.120309 Retrieved from: https://hdl.handle.net/20.500.14740/6960

Title

Sodium-dependent uptake of glutamate by novel ApGltS enhanced growth under salt stress of halotolerant cyanobacterium aphanothece halophytica

Author(s)

Boonburapong B.
 Laloknam S.
 Yamada N.
 Incharoensakdi A.
 Takabe T.

Abstract

Glutamate is a major free amino acid in cyanobacteria, but its transport properties remain largely unknown. In this study, we found that a halotolerant cyanobacterium, Aphanothece halophytica, contained a sodium dependent glutamate transporter (ApGltS). The deduced amino acid sequence of ApGltS exhibited low homology (18-19% identity) to GltS from Synechocystis sp. PCC 6803 (slr1145) and Escherichia coli. The predicted ApGltS consisted of 476 amino acid residues with a molecular weight of 50,976 Da. As analysed by hydropathy profiling, ApGltS contains 11 transmembrane segments. The ApgltS gene was isolated and expressed in E. coli ME9107, which is deficient in glutamate uptake. ME9107, expressing ApGltS, took up glutamate and its rates increased with increasing concentrations of NaCl. Kinetics studies revealed that ApGltS is a high-affinity glutamate transporter with a Km of about 5μM. The presence of 0.5M NaCl in the assay medium increased Vmax by about 3-fold. Competition experiments revealed that glutamate, glutamine, aspartate, and asparagine inhibited glutamate uptake. The level of mRNA for ApgltS was higher in A. halophytica grown at high salinity. Under high salinity conditions supplemented with glutamate, A. halophytica showed a significant increase in intracellular glycine betaine.

Subject(s)

Amino acid residues
 Amino acid sequence
 Amino acid uptake
 Aphanothece halophytica
 Aspartates
 Cyanobacterium
 E. coli
 Enhanced growth
 Free amino acids
 Glutamate transporters
 Glycine betaine
 Halotolerant
 High salinity
 Kinetics studies
 Salt stresss
 Synechocystis sp. PCC 6803
 Transmembrane segments
 Escherichia coli
 Hardwoods
 Salinity measurement
 Sodium
 Sodium chloride
 Transport properties
 Amino acids
 Amino acid transporter
 Bacterial protein
 Betaine
 Cotransporter
 Escherichia coli protein
 GltS protein, E coli
 Glutamate transporter
 Glutamic acid
 Messenger RNA
 Recombinant protein
 Sodium chloride
 Amino acid sequence
 Article
 Biosynthesis
 Cyanobacterium
 Drug effect
 Enzyme specificity
 Escherichia coli
 Genetics
 Growth, development and aging
 Kinetics
 Metabolism
 Molecular genetics
 Molecular weight
 Phylogeny
 Physiology
 Protein tertiary structure
 Salinity
 Salt tolerance
 Sequence homology
 Amino Acid Sequence
 Amino Acid Transport System X-AG
 Amino Acid Transport Systems, Acidic
 Bacterial Proteins
 Betaine
 Cyanobacteria
 Escherichia coli
 Escherichia coli Proteins
 Glutamic Acid
 Kinetics
 Molecular Sequence Data
 Molecular Weight
 Phylogeny
 Protein Structure, Tertiary
 Recombinant Proteins
 RNA, Messenger
 Salinity
 Salt-Tolerance
 Sequence Homology, Amino Acid
 Sodium Chloride
 Substrate Specificity
 Symporters
 Aphanothece halophytica
 Cyanobacteria
 Escherichia coli
 Synechocystis sp. PCC 6803

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URI

https://hdl.handle.net/20.500.14740/6960

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Scopus: Year 1983-2021

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