A CMP-sialic acid transporter cloned from Arabidopsis thaliana

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• 作者：Hans Bakker ; Franç ; oise Routier ; Angel Ashikov ; Detlef Neumann ; Dirk Bosch ; Rita Gerardy-Schahn
• 关键词：CMP-sialic acid ; CMP-Kdo ; Nucleotide sugar transporter ; Golgi transport
• 刊名：Carbohydrate Research
• 出版年：2008
• 出版时间：11 August 2008
• 年：2008
• 卷：343
• 期：12
• 页码：2148-2152
• 全文大小：208 K

文摘

Sialylation of glycans is ubiquitous in vertebrates, but was believed to be absent in plants, arthropods, and fungi. However, recently evidence has been provided for the presence of sialic acid in these evolutionary clades. In addition, homologs of mammalian genes involved in sialylation can be found in the genomes of these taxa and for some Drosophila enzymes, involvement in sialic acid metabolism has been documented. In plant genomes, homologs of sialyltransferase genes have been identified, but there activity could not be confirmed. Several mammalian cell lines exist with defects in the sialylation pathway. One of these is the Chinese hamster ovary cell line Lec2, deficient in CMP-sialic acid transport to the Golgi lumen. These mutants provide the possibility to clone genes by functional complementation. Using expression cloning, we have identified an Arabidopsis thaliana nucleotide sugar transporter that is able to complement the CMP-sialic acid transport deficiency of Lec2 cells. The isolated gene (At5g41760) is a member of the triose-phosphate/nucleotide sugar transporter gene family. Recombinant expression of the gene in yeast and testing in vitro confirmed its ability to transport CMP-sialic acid.