Abstract
Aluminum (Al) tolerance in wheat appears to be controlled by Al activated malate transporter (ALMT1) localized on the plasma membrane. Hydrophobicity profile of ALMT1 protein predicts 5 to 8 transmembrane regions. To elucidate the transmembrane topology of this transporter, we examined the orientations of N and C termini and intra-membrane loop domains of ALMT1 protein. The ALMT1 protein tagged with GFP or His epitope was transiently expressed in animal cells. To determine the localization of epitops in the cells, the anti-ALMT1 antiserums raised against the peptides of ALMT1 N or C terminus were used, without or with a detergent (Triton X) to penetrate the antibodies into cells. The observations of GFP as well as His tag, N- and C- terminal epitopes under fluorescence microscope suggest that the N and C termini of ALMT1 protein face toward the outside of the membrane.
