High impact information on RSW10

• A mutation in an Arabidopsis ribose 5-phosphate isomerase reduces cellulose synthesis and is rescued by exogenous uridine [1].
• Although RPI is intimately involved with many biochemical pathways, media supplementation experiments suggest that the visible phenotype results from a defect in the production of pyrimidine-based sugar-nucleotide compounds, most likely uridine 5'-diphosphate-glucose, the presumed substrate of cellulose synthase [1].
• Two of three RPI sequences in the nuclear genome are cytoplasmic, while the third has a putative chloroplast transit sequence [1].
• Map-based cloning showed that the mutated gene (At1g71100) encodes a ribose 5-phosphate isomerase (RPI) and that the rsw10 mutation replaces a conserved glutamic acid residue with lysine [1].
• The prominence of the rsw10 phenotype in roots probably reflects RSW10 being the only cytosolic RPI in this tissue and the gene encoding the plastid RPI being relatively weakly expressed [1].

References