Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Price DR
,
Feng H
,
Baker JD
,
Bavan S
,
Luetje CW
,
Wilson AC
.
???displayArticle.abstract???
Endosymbiotic associations have played a major role in evolution. However, the molecular basis for the biochemical interdependence of these associations remains poorly understood. The aphid-Buchnera endosymbiosis provides a powerful system to elucidate how these symbioses are regulated. In aphids, the supply of essential amino acids depends on an ancient nutritional symbiotic association with the gamma-proteobacterium Buchnera aphidicola. Buchnera cells are densely packed in specialized aphid bacteriocyte cells. Here we confirm that five putative amino acid transporters are highly expressed and/or highly enriched in Acyrthosiphon pisum bacteriocyte tissues. When expressed in Xenopus laevis oocytes, two bacteriocyte amino acid transporters displayed significant levels of glutamine uptake, with transporter ACYPI001018, LOC100159667 (named here as Acyrthosiphon pisum glutamine transporter 1, ApGLNT1) functioning as the most active glutamine transporter. Transporter ApGLNT1 has narrow substrate selectivity, with high glutamine and low arginine transport capacity. Notably, ApGLNT1 has high binding affinity for arginine, and arginine acts as a competitive inhibitor for glutamine transport. Using immunocytochemistry, we show that ApGLNT1 is localized predominantly to the bacteriocyte plasma membrane, a location consistent with the transport of glutamine from A. pisum hemolymph to the bacteriocyte cytoplasm. On the basis of functional transport data and localization, we propose a substrate feedback inhibition model in which the accumulation of the essential amino acid arginine in A. pisum hemolymph reduces the transport of the precursor glutamine into bacteriocytes, thereby regulating amino acid biosynthesis in the bacteriocyte. Structural similarities in the arrangement of hosts and symbionts across endosymbiotic systems suggest that substrate feedback inhibition may be mechanistically important in other endosymbioses.
Baumann,
Genetics, physiology, and evolutionary relationships of the genus Buchnera: intracellular symbionts of aphids.
1995, Pubmed
Baumann,
Genetics, physiology, and evolutionary relationships of the genus Buchnera: intracellular symbionts of aphids.
1995,
Pubmed
Bermingham,
Impact of host developmental age on the transcriptome of the symbiotic bacterium Buchnera aphidicola in the pea aphid (Acyrthosiphon pisum).
2009,
Pubmed
Burry,
Controls for immunocytochemistry: an update.
2011,
Pubmed
DOY,
Feedback control of tryptophan biosynthesis.
1960,
Pubmed
Desai,
Regulation of arabinose and xylose metabolism in Escherichia coli.
2010,
Pubmed
Duncan,
Novel male-biased expression in paralogs of the aphid slimfast nutrient amino acid transporter expansion.
2011,
Pubmed
Hansen,
Aphid genome expression reveals host-symbiont cooperation in the production of amino acids.
2011,
Pubmed
International Aphid Genomics Consortium,
Genome sequence of the pea aphid Acyrthosiphon pisum.
2010,
Pubmed
Koga,
Cellular mechanism for selective vertical transmission of an obligate insect symbiont at the bacteriocyte-embryo interface.
2012,
Pubmed
Kozak,
Structural features in eukaryotic mRNAs that modulate the initiation of translation.
1991,
Pubmed
Livak,
Analysis of relative gene expression data using real-time quantitative PCR and the 2(-Delta Delta C(T)) Method.
2001,
Pubmed
Lodwig,
Amino-acid cycling drives nitrogen fixation in the legume-Rhizobium symbiosis.
2003,
Pubmed
Macdonald,
The central role of the host cell in symbiotic nitrogen metabolism.
2012,
Pubmed
Moran,
Bacterial endosymbionts in animals.
2000,
Pubmed
Moran,
Regulation of transcription in a reduced bacterial genome: nutrient-provisioning genes of the obligate symbiont Buchnera aphidicola.
2005,
Pubmed
Nakabachi,
Transcriptome analysis of the aphid bacteriocyte, the symbiotic host cell that harbors an endocellular mutualistic bacterium, Buchnera.
2005,
Pubmed
Poliakov,
Large-scale label-free quantitative proteomics of the pea aphid-Buchnera symbiosis.
2011,
Pubmed
Poole,
Carbon and nitrogen metabolism in Rhizobium.
2000,
Pubmed
Prell,
Legumes regulate Rhizobium bacteroid development and persistence by the supply of branched-chain amino acids.
2009,
Pubmed
Prell,
Role of symbiotic auxotrophy in the Rhizobium-legume symbioses.
2010,
Pubmed
Price,
Genome expansion and differential expression of amino acid transporters at the aphid/Buchnera symbiotic interface.
2011,
Pubmed
Reymond,
Different levels of transcriptional regulation due to trophic constraints in the reduced genome of Buchnera aphidicola APS.
2006,
Pubmed
Shigenobu,
Genome sequence of the endocellular bacterial symbiont of aphids Buchnera sp. APS.
2000,
Pubmed
Shigenobu,
Genomic revelations of a mutualism: the pea aphid and its obligate bacterial symbiont.
2011,
Pubmed
Sun,
Crystal structure of a bacterial homologue of glucose transporters GLUT1-4.
2012,
Pubmed
Thomas,
A fragile metabolic network adapted for cooperation in the symbiotic bacterium Buchnera aphidicola.
2009,
Pubmed
UMBARGER,
Evidence for a negative-feedback mechanism in the biosynthesis of isoleucine.
1956,
Pubmed
Viñuelas,
Conservation of the links between gene transcription and chromosomal organization in the highly reduced genome of Buchnera aphidicola.
2007,
Pubmed
Wilson,
Genomic insight into the amino acid relations of the pea aphid, Acyrthosiphon pisum, with its symbiotic bacterium Buchnera aphidicola.
2010,
Pubmed
