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Title: The elaborate route for UDP-arabinose delivery into the Golgi of plants

In plants, L-Arabinose (Ara) is a key component of cell wall polymers, glycoproteins, as well as flavonoids, and signaling peptides. Whereas the majority of Ara found in plant glycans occurs as a furanose ring (Araf), the activated precursor has a pyranose ring configuration (UDP-Arap). The biosynthesis of UDP-Arap mainly occurs via the epimerization of UDP-xylose (UDP-Xyl) in the Golgi lumen. Given that the predominant Ara form found in plants is Araf, UDP-Arap must exit the Golgi to be interconverted into UDPAraf by UDP-Ara mutases that are located outside on the cytosolic surface of the Golgi. Subsequently, UDP-Araf must be transported back into the lumen. During this step it is vital because glycosyltransferases, the enzymes mediating the glycosylation reactions, are located within the Golgi lumen, and UDP-Arap, synthesized within the Golgi, is not their preferred substrate. Therefore, the transport of UDP-Araf into the Golgi is a prerequisite. Although this step is critical for cell wall biosynthesis and the glycosylation of proteins and signaling peptides, the identification of these transporters has remained elusive. In this study, we present data demonstrating the identification and characterization of a family of Golgilocalized UDP-Araf transporters in Arabidopsis. The application of a proteoliposome-based transport assay revealed thatmore » four members of the nucleotide sugar transporter (NST) family can efficiently transport UDP-Araf in vitro. Subsequent analysis of mutant lines affected in the function of these NSTs confirmed their role as UDP-Araf transporters in vivo.« less
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [5] ;  [4] ; ORCiD logo [3] ;  [6] ; ORCiD logo [1] ;  [1]
  1. Univ. of Melbourne (Australia). School of BioSciences; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Joint BioEnergy Inst.
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Joint BioEnergy Inst.
  3. Univ. of Georgia, Athens, GA (United States). Complex Carbohydrate Research Center
  4. Univ. of Melbourne (Australia). School of BioSciences
  5. Univ. of Andres Bello, Santiago (Chile). Center for Plant Biotechnology
  6. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Joint BioEnergy Inst.; Univ. of California, Berkeley, CA (United States). Dept. of Plant and Microbial Biology
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Proceedings of the National Academy of Sciences of the United States of America
Additional Journal Information:
Journal Volume: 114; Journal Issue: 16; Journal ID: ISSN 0027-8424
National Academy of Sciences, Washington, DC (United States)
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
59 BASIC BIOLOGICAL SCIENCES; golgi apparatus; nucleotide sugars; membrane transport; arabinose
OSTI Identifier: