TY  - JOUR
U1  - Zeitschriftenartikel, wissenschaftlich - begutachtet (reviewed)
A1  - Feng, Honglin
A1  - Edwards, Noel
A1  - Anderson, Catriona M. H.
A1  - Althaus, Mike
A1  - Duncan, Rebecca P.
A1  - Hsu, Yu-Ching
A1  - Luetje, Charles W.
A1  - Price, Daniel R. G.
A1  - Wilson, Alex C. C.
A1  - Thwaites, David T.
T1  - Trading amino acids at the aphid-Buchnera symbiotic interface
JF  - Proceedings of the National Academy of Sciences of the United States of America
N2  - Plant sap-feeding insects are widespread, having evolved to occupy diverse environmental niches despite exclusive feeding on an impoverished diet lacking in essential amino acids and vitamins. Success depends exquisitely on their symbiotic relationships with microbial symbionts housed within specialized eukaryotic bacteriocyte cells. Each bacteriocyte is packed with symbionts that are individually surrounded by a host-derived symbiosomal membrane representing the absolute host-symbiont interface. The symbiosomal membrane must be a dynamic and selectively permeable structure to enable bidirectional and differential movement of essential nutrients, metabolites, and biosynthetic intermediates, vital for growth and survival of host and symbiont. However, despite this crucial role, the molecular basis of membrane transport across the symbiosomal membrane remains unresolved in all bacteriocyte-containing insects. A transport protein was immuno-localized to the symbiosomal membrane separating the pea aphid Acyrthosiphon pisum from its intracellular symbiont Buchnera aphidicola. The transporter, A. pisum nonessential amino acid transporter 1, or ApNEAAT1 (gene: ACYPI008971), was characterized functionally following heterologous expression in Xenopus oocytes, and mediates both inward and outward transport of small dipolar amino acids (serine, proline, cysteine, alanine, glycine). Electroneutral ApNEAAT1 transport is driven by amino acid concentration gradients and is not coupled to transmembrane ion gradients. Previous metabolite profiling of hemolymph and bacteriocyte, alongside metabolic pathway analysis in host and symbiont, enable prediction of a physiological role for ApNEAAT1 in bidirectional host-symbiont amino acid transfer, supplying both host and symbiont with indispensable nutrients and biosynthetic precursors to facilitate metabolic complementarity.
KW  - symbiosis
KW  - metabolic integration
KW  - amino acid transport
SN  - 0027-8424
SS  - 0027-8424
U6  - https://doi.org/10.1073/pnas.1906223116
DO  - https://doi.org/10.1073/pnas.1906223116
PM  - 31337682
VL  - 116
IS  - 32
SP  - 16003
EP  - 16011
S1  - 9
PB  - National Academy of Sciences
ER  -