Sugar transporters of the major facilitator superfamily in aphids; from gene prediction to functional characterization

Abstract

Abstracti mb_918 97..112Analysis of the pea aphid (Acyrthosiphon pisum) genome using signatures specific to the Major Facilitator Superfamily (Pfam Clan CL0015) and the Sugar_tr family (Pfam Family PF00083) has identified 54 genes encoding potential sugar transporters, of which 38 have corresponding ESTs. Twenty-nine genes contain the InterPro IPR003663 hexose transporter signature. The protein encoded by Ap_ST3, the most abundantly expressed sugar transporter gene, was functionally characterized by expression as a recombinant protein. Ap_ST3 acts as a low-affinity uniporter for fructose and glucose that does not depend on Na + or H + for activity. Ap_ST3 was expressed at elevated levels in distal gut tissue, consistent with a role in gut sugar transport. The A. pisum genome shows evidence of duplications of sugar transporter genes.Keywords: facilitated substrate transport, transmembrane protein, gut metabolism, in situ localization, yeast expression system.

Herbivory-induced glucose transporter gene expression in the brown planthopper, Nilaparvata lugens

“…The Nlst16 gene was activated under high sugar conditions, which was not observed in case of the Nlst1 glucose transporter gene. The characteristics of sugar transporters expressed in the gut have been examined in phloem feeding insects such as BPH or aphids, where they have been found to mediate passive sugar incorporations across the gut membranes (Price et al, 2007b(Price et al, , 2010Kikuta et al, 2010;Price and Gatehouse, 2014). The phloem sap entered the gut through continuous BPH feeding, resulting in a sugar-rich environment of the midgut lumen cavity.…”

Large-Scale Label-Free Quantitative Proteomics of the Pea aphid-Buchnera Symbiosis

“…These transporters include two further amino acid transporters, ACYPI000536 (#412, 0.051%), the ortholog of the Drosophila protein CG8785 and ACYPI008971 (#599, 0.029%), mediating H ϩ coupled amino acid transport; and a sugar transporter ACYPI001077 (#613, 0.028%), designated ApST9 (Price et al, 2010). Four further members of the MFS superfamily identified in BR samples are probably not sugar-transporters (ACYPI002278_ApST38, ACYPI010074_ ApST42, ACYPI007742_ApST45, and ACYPI009892, which has no ApST designation) (50). The bacteriocyte samples had two monocarboxylate transporters (ACYPI002559, #692, 0.021%, and ACYPI002787, #669, 0.023%), the candidate substrates for which could include glutamate and aspartate transferred from aphid to Buchnera (Figs.…”

Sugar transporter genes of the brown planthopper, Nilaparvata lugens: A facilitated glucose/fructose transporter

“…However, relatively little information is currently available on insect sugar transporters (Burchmore et al, 2003;Chen et al, 2006;Caccia et al, 2007;Kikawada et al, 2007;Price et al, 2007bPrice et al, , 2010Kanamori et al, 2010). The sugar transporter NlHT1, which was previously identified in the BPH, is a facilitative glucose transporter and is specifically expressed in the midgut (Price et al, 2007b).…”

“…Because fructose is routinely used as an energy source, another transporter for fructose uptake is believed to be present in the midgut of the BPH. Recently, the facilitated sugar transporter Ap_ST3 was identified in Acyrthosiphon pisum; Ap_ST3 has been found to transport both glucose and fructose (Price et al, 2010).…”