Structural analysis of a plant sucrose carrier using monoclonal antibodies and bacteriophage lambda surface display.
Monoclonal antibodies were raised and selected against recombinant Plantago major PmSUC2 sucrose carrier protein. Epitopes of two monoclonal antibodies (PS2-1A2 and PS2-4D4) were mapped using N-terminally truncated PmSUC2 proteins and a lambda library displaying random PmSUC2 peptides. PS2-1A2 recognizes an octapeptide close to the N-terminus of PmSUC2, PS2-4D4 binds to a decapeptide at the very C-terminus. Analyses of antibody binding to yeast protoplasts with functionally active, tagged PmSUC2 protein revealed that both epitopes are located in cytoplasmic domains of PmSUC2. These results support a model for plant sucrose transporters containing 12 transmembrane helices with the N-terminus and the C-terminus on the cytoplasmic side of the plasma membrane.
Lehrstuhl Botanik II, Molekulare Pflanzenphysiologie, Universität Erlangen-Nürnberg, Erlangen, Germany.
J
J
Stolz
A
A
Ludwig
R
R
Stadler
C
C
Biesgen
K
K
Hagemann
N
N
Sauer
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D000918:Antibody Specificity; D010582:Bacteriophage lambda; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000648:ultrastructure*; D002462:Cell Membrane / Q000737:chemistry; D016764:Cell Polarity; D003593:Cytoplasm / Q000737:chemistry; D018604:Epitope Mapping; D026901:Membrane Transport Proteins; D008969:Molecular Sequence Data; D019151:Peptide Library; D010940:Plant Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000648:ultrastructure*; D010943:Plantago; D010946:Plants, Medicinal; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000276:immunology / Q000378:metabolism; D013395:Sucrose / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D002352:Carrier Proteins; D026901:Membrane Transport Proteins; D019151:Peptide Library; D010940:Plant Proteins; D011994:Recombinant Proteins; C078729:sucrose transport protein, plant; D013395:Sucrose