AtSTP6, a new pollen-specific H+-monosaccharide symporter from Arabidopsis.
This paper describes the molecular, kinetic, and physiological characterization of AtSTP6, a new member of the Arabidopsis H(+)/monosaccharide transporter family. The AtSTP6 gene (At3g05960) is interrupted by two introns and encodes a protein of 507 amino acids containing 12 putative transmembrane helices. Expression in yeast (Saccharomyces cerevisiae) shows that AtSTP6 is a high-affinity (K(m) = 20 microM), broad-spectrum, and uncoupler-sensitive monosaccharide transporter that is targeted to the plasma membrane and that can complement a growth deficiency resulting from the disruption of most yeast hexose transporter genes. Analyses of AtSTP6-promoter::GUS plants and in situ hybridization experiments detected AtSTP6 expression only during the late stages of pollen development. A transposon-tagged Arabidopsis mutant was isolated and homozygous plants were analyzed for potential effects of the Atstp6 mutation on pollen viability, pollen germination, fertilization, and seed production. However, differences between wild-type and mutant plants could not be observed.
Scholz-Starke
Joachim
J
Molekulare Pflanzenphysiologie, Universität Erlangen-Nürnberg, Staudtstrasse 5, D-91058 Erlangen, Germany.
Büttner
Michael
M
Sauer
Norbert
N
D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004251:DNA Transposable Elements / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D005298:Fertility / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D005816:Genetic Complementation Test; D005966:Glucuronidase / Q000235:genetics / Q000378:metabolism; D017403:In Situ Hybridization; D007700:Kinetics; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000235:genetics* / Q000378:metabolism; D016254:Mutagenesis, Insertional; D009154:Mutation; D011058:Pollen / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics; D012639:Seeds / Q000254:growth & development; D017422:Sequence Analysis, DNA; D027981:Symporters
D029681:Arabidopsis Proteins; C490342:AtSTP6 protein, Arabidopsis; D004251:DNA Transposable Elements; D018076:DNA, Complementary; D008565:Membrane Proteins; D009004:Monosaccharide Transport Proteins; D027981:Symporters; C089820:monosaccharide-hydrogen cotransporter; D005966:Glucuronidase