Identification and characterization of a sucrose transporter isolated from the developing cotyledons of soybean.
Reduced carbon produced in mature leaves is distributed throughout plants in the form of sucrose. Sucrose transporter proteins (SUT) play a crucial role in transporting sucrose. We isolated a cDNA encoding a sucrose transporter, GmSUT1, which is expressed in the developing cotyledons of soybean (Glycine max). [14C]sucrose uptake assays demonstrate that GmSUT1 has a K(m) of 5.6mM and a V(max) of 5.8 nmol sucrose min(-1)(mg cells)(-1), which are similar to those of the low-affinity-high-capacity sucrose transporter family. GmSUT1 protein accumulates gradually during cotyledon development, correlating with increasing sucrose levels in the maturing cotyledons. Collectively, these data suggest that GmSUT1 plays an active role in the movement of sucrose into the developing seeds.
Aldape
Mike J
MJ
School of Molecular Biosciences, Washington State University, Pullman, WA 99163-4234, USA.
Elmer
Aaron M
AM
Chao
Wun S
WS
Grimes
Howard D
HD
D001692:Biological Transport; D002244:Carbon / Q000378:metabolism; D018548:Cotyledon / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D018745:Genome, Plant; D006863:Hydrogen-Ion Concentration; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000235:genetics; D013025:Glycine max / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013395:Sucrose / Q000378:metabolism* / Q000493:pharmacokinetics
D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D010940:Plant Proteins; C078729:sucrose transport protein, plant; D013395:Sucrose; D002244:Carbon