TY - JOUR
T1 - Functional characterization of the α-glucoside transporter Sut1p from Schizosaccharomyces pombe, the first fungal homologue of plant sucrose transporters
AU - Reinders, A.
AU - Ward, J. M.
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2001
Y1 - 2001
N2 - Disaccharide transporters have not previously been identified in Schizosaccharomyces pombe. This is in contrast to Saccharomyces cerevisiae in which several maltose permeases belonging to the sugar porter (SP) family have been characterized. Here we report that a novel S. pombe gene, sut1+, encodes a proton-coupled disaccharide uptake transporter in the glycoside-pentoside-hexuronide (GPH):cation symporter family. Previously, members of the GPH family were restricted to bacteria and plants. The closest homologues of sut1+ are the sucrose uptake transporters (SUTs) from higher plants that transport sucrose with a higher affinity than maltose. The transport function of Sut1p was analysed by expression in S. cerevisiae. Sut1p was found to transport maltose with a Km of 6.5 ± 0.4 mM and sucrose with a Km of 36.3 ± 9.7 mM. Therefore, the substrate specificity of Sut1p from S. pombe is different from that of its plant homologues. Glucose repression of sut1+ at the transcriptional level is also consistent with a physiological function for Sut1p in maltose uptake. These results indicate that, unlike S. cerevisiae, S. pombe utilizes maltose transporters derived from a common ancestor with the plant SUTs.
AB - Disaccharide transporters have not previously been identified in Schizosaccharomyces pombe. This is in contrast to Saccharomyces cerevisiae in which several maltose permeases belonging to the sugar porter (SP) family have been characterized. Here we report that a novel S. pombe gene, sut1+, encodes a proton-coupled disaccharide uptake transporter in the glycoside-pentoside-hexuronide (GPH):cation symporter family. Previously, members of the GPH family were restricted to bacteria and plants. The closest homologues of sut1+ are the sucrose uptake transporters (SUTs) from higher plants that transport sucrose with a higher affinity than maltose. The transport function of Sut1p was analysed by expression in S. cerevisiae. Sut1p was found to transport maltose with a Km of 6.5 ± 0.4 mM and sucrose with a Km of 36.3 ± 9.7 mM. Therefore, the substrate specificity of Sut1p from S. pombe is different from that of its plant homologues. Glucose repression of sut1+ at the transcriptional level is also consistent with a physiological function for Sut1p in maltose uptake. These results indicate that, unlike S. cerevisiae, S. pombe utilizes maltose transporters derived from a common ancestor with the plant SUTs.
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U2 - 10.1046/j.1365-2958.2001.02237.x
DO - 10.1046/j.1365-2958.2001.02237.x
M3 - Article
C2 - 11136464
AN - SCOPUS:0035154989
SN - 0950-382X
VL - 39
SP - 445
EP - 455
JO - Molecular Microbiology
JF - Molecular Microbiology
IS - 2
ER -