Passive fructose transporters in disease: a molecular overview of their structural specificity

The SLC2 family of facilitative Glucose transporters (Gluts) contains 14 isoforms divided into three classes based on amino acid sequence. While the majority of these proteins transport glucose, a subset can transport fructose. Recently, fructose and the Gluts responsible for fructose uptake have received increased interest due to the correlation between high fructose consumption and early onset of metabolic syndrome. In addition, the up-regulation of Gluts in certain cancers has made possible the development of a number of fructose probes for imaging cancer. Although structure activity data has defined some aspects of fructose-specific uptake, a far more detailed clarification of the variables governing the onset and progression of fructose-correlated diseases is still needed. Here, we summarize what is known about molecular structure and fructose uptake as it relates to the correlation of fructose and disease.