The sugar phosphate/phosphate exchanger family SLC37

摘要

The solute-carrier (SLC) superfamily is divided into 55 different families of genes coding for integral membrane proteins, which transport not only all kinds of endogenous solute substrates, but also exogenous drugs and chemicals. The SLC37 transporters are members of the organophosphate:Pi antiporter family (OPA) and therefore they belong to the major facilitator superfamily (MFS). The SLC37 family members diverged early in evolution. SLC37A1 and SLC37A2 transporters are closely related and they have 57% of identical amino acids, while they have an average of 31% identical amino acids with SLC37A3. SLC37A4 is however quite different from them, sharing an average of 15% identity with the other three members. The SLC37A4 gene (also known as glucose-6-phosphate transporter, G6PT) is mutated in the glycogen storage disease non-1A type, therefore it is well studied both at the DNA and protein levels. Major function of SLC37A4 is to preserve interprandial glucose homeostasis. Data on SLC37A1 and SLC37A2genes expression are available both in humans and in mice, but there is still little information on their protein function. Even if they are homologous to glycerol-3-phosphate transporters, they were described to transport glucose-6-phosphate; therefore, they might be multisolute carriers. SLC37A3 is still poorly investigated and the only described feature is that it seems not to transport glucose-6-phosphate.