The C-terminal tetrapeptide HWFW of the Chlorella HUP1 hexose/H(+)-symporter is essential for full activity and an alpha-helical structure of the C-terminus.
C-terminal tails of plant hexose/H(+)-symporters of the major facilitator superfamily contain a highly conserved motif of four amino acids: HWFW. A deletion of these four amino acids in the Chlorella HUP1 protein leads to a decrease in transport activity by a factor of 3-4. The mutated tail is highly sensitive to trypsin; it does not show alpha-helical conformation in contrast to the wild type C-terminal peptide with an alpha-helical content of at least 15%. The production of monoclonal antibody 416B8 recognizing an epitope within the central loop of HUP1 protein has been a prerequisite for the experiments described.
Grassl
R
R
Lehrstuhl für Zellbiologie und Pflanzenphysiologie, Universität Regensburg, Universitätsstr. 31, 93040, Regensburg, Germany. renate.grassl@biologie.uni-regensburg.de
Robl
I
I
Opekarovà
M
M
Tanner
W
W
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D002708:Chlorella / Q000378:metabolism*; D002942:Circular Dichroism; D005260:Female; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008958:Models, Molecular; D009004:Monosaccharide Transport Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D010446:Peptide Fragments / Q000737:chemistry; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D027981:Symporters; D014357:Trypsin / Q000378:metabolism*
D000911:Antibodies, Monoclonal; D008565:Membrane Proteins; D009004:Monosaccharide Transport Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D027981:Symporters; C089820:monosaccharide-hydrogen cotransporter; D014357:Trypsin