TY - JOUR
T1 - Phylogenetic evidence for a fusion of archaeal and bacterial SemiSWEETs to form eukaryotic SWEETs and identification of SWEET hexose transporters in the amphibian chytrid pathogen Batrachochytrium dendrobatidis
AU - Hu, Yi Bing
AU - Sosso, Davide
AU - Qu, Xiao Qing
AU - Chen, Li Qing
AU - Ma, Lai
AU - Chermak, Diane
AU - Zhang, De Chun
AU - Frommer, Wolf B.
PY - 2016/10
Y1 - 2016/10
N2 - SWEETs represent a new class of sugar transporters first described in plants, animals, and humans and later in prokaryotes. PlantSWEETs play key roles in phloemloading, seed filling, and nectar secretion,whereas the role of archaeal, bacterial, and animal transporters remains elusive. Structural analyses show that eukaryotic SWEETs are composed of 2 triple-helix bundles (THBs) fused via an inversion linker helix, whereas prokaryotic SemiSWEETs contain only a single THB and require homodimerization to form transport pores. This study indicates that SWEETs retained sugar transport activity in all kingdoms of life, and that SemiSWEETs are likely their ancestral units. Fusion of oligomeric subunits into single polypeptides during evolution of eukaryotes is commonly found for transporters. Phylogenetic analyses indicate that THBs of eukaryotic SWEETs may not have evolved by tandem duplication of an open reading frame, but rather originated by fusion between an archaeal and a bacterial SemiSWEET, which potentially explains the asymmetry of eukaryotic SWEETs. Moreover, despite the ancient ancestry, SWEETs had not been identified in fungi or oomycetes. Here, we report the identification of SWEETs in oomycetes as well as SWEETs and a potential SemiSWEET in primitive fungi. BdSWEET1 and BdSWEET2 from Batrachochytrium dendrobatidis, a nonhyphal zoosporic fungus that causes global decline in amphibians, showed glucose and fructose transport activities.
AB - SWEETs represent a new class of sugar transporters first described in plants, animals, and humans and later in prokaryotes. PlantSWEETs play key roles in phloemloading, seed filling, and nectar secretion,whereas the role of archaeal, bacterial, and animal transporters remains elusive. Structural analyses show that eukaryotic SWEETs are composed of 2 triple-helix bundles (THBs) fused via an inversion linker helix, whereas prokaryotic SemiSWEETs contain only a single THB and require homodimerization to form transport pores. This study indicates that SWEETs retained sugar transport activity in all kingdoms of life, and that SemiSWEETs are likely their ancestral units. Fusion of oligomeric subunits into single polypeptides during evolution of eukaryotes is commonly found for transporters. Phylogenetic analyses indicate that THBs of eukaryotic SWEETs may not have evolved by tandem duplication of an open reading frame, but rather originated by fusion between an archaeal and a bacterial SemiSWEET, which potentially explains the asymmetry of eukaryotic SWEETs. Moreover, despite the ancient ancestry, SWEETs had not been identified in fungi or oomycetes. Here, we report the identification of SWEETs in oomycetes as well as SWEETs and a potential SemiSWEET in primitive fungi. BdSWEET1 and BdSWEET2 from Batrachochytrium dendrobatidis, a nonhyphal zoosporic fungus that causes global decline in amphibians, showed glucose and fructose transport activities.
KW - Gene Conversion
KW - LECA
KW - Oomycete
KW - Sugar Transport
KW - Transporter Evolution
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U2 - 10.1096/fj.201600576R
DO - 10.1096/fj.201600576R
M3 - Article
C2 - 27411857
AN - SCOPUS:84990854945
VL - 30
SP - 3644
EP - 3654
JO - FASEB Journal
JF - FASEB Journal
SN - 0892-6638
IS - 10
ER -