Cloning and expression of amino acid transporters from broad bean.
This work describes the isolation of a full-length (VfAAP2) and three partial amino acid transporter genes (VfAAPa, VfAAPb, VfAAPc) from broad bean (Vicia faba L.). The function of VfAAP2 was tested by heterologous expression in a yeast mutant deficient in proline uptake. VfAAP2 mediates proton-dependent proline uptake with an apparent Km of about 1 mM. Analysis of substrate specificity by competition experiments showed that aromatic amino acids, neutral aliphatic acids and L-citrulline are the best competitors, whereas basic amino acids do not compete with proline. Northern analysis indicates that all VfAAPs exhibit different patterns of expression. VfAAP2 is most strongly expressed in the stem and at a lower level in sink leaves and pods. VfAAPa, VfAAPb and VfAAPc are most strongly expressed in the flowers, but their expression in the other organs varies.
Montamat
F
F
Laboratoire de Physiologie et Biochimie Végétales, ERS CNRS 6099, UFR Sciences, Université de Poitiers, France.
Maurousset
L
L
Tegeder
M
M
Frommer
W
W
Delrot
S
S
D000595:Amino Acid Sequence; D026905:Amino Acid Transport Systems; D001483:Base Sequence; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics* / Q000302:isolation & purification; D003001:Cloning, Molecular; D007887:Fabaceae; D015870:Gene Expression; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000235:genetics* / Q000302:isolation & purification; D010946:Plants, Medicinal; D017386:Sequence Homology, Amino Acid
D026905:Amino Acid Transport Systems; D002352:Carrier Proteins; D010940:Plant Proteins