Sugar transporter SWEET1 explained

Sugar transporter SWEET1, also known as RAG1-activating protein 1 and stromal cell protein (SCP), is a membrane protein that in humans is encoded by the SLC50A1 gene.^[1] SWEET1 is the sole transporter from the SLC50 (SWEET) gene family present in the genomes of most animal species, with the exception of the nematode Caenorhabditis elegans, which has seven.^[2]

SWEET1 is a broadly-expressed glucose transporter. As the SWEET family has been identified relatively recently, the full range of its functions in animals is not yet clear.^[3] However, the bovine SLC50A1 homologue is associated with lactose concentration in milk,^[4] and the CiRGA homologue in the sea squirt Ciona intestinalis is essential for tissue differentiation during embryogenesis, especially the development of the notochord.^[5] SWEET genes are common in plant genomes, with around twenty paralogues ^[2] functioning as both sucrose and hexose transporters, and are also associated with pathogen susceptibility.^{[2] [6]}

Further reading

• Barnhill JC, Stokes AJ, Koblan-Huberson M, Shimoda LM, Muraguchi A, Adra CN, Turner H . RGA protein associates with a TRPV ion channel during biosynthesis and trafficking . Journal of Cellular Biochemistry . 91 . 4 . Mar 2004 . 14991772 . 10.1002/jcb.10775 . 808–20. 44629547 .
• Pankratz N, Beecham GW, DeStefano AL, Dawson TM, Doheny KF, Factor SA, Hamza TH, Hung AY, Hyman BT, Ivinson AJ, Krainc D, Latourelle JC, Clark LN, Marder K, Martin ER, Mayeux R, Ross OA, Scherzer CR, Simon DK, Tanner C, Vance JM, Wszolek ZK, Zabetian CP, Myers RH, Payami H, Scott WK, Foroud T . Meta-analysis of Parkinson's disease: identification of a novel locus, RIT2 . Annals of Neurology . 71 . 3 . Mar 2012 . 22451204 . 10.1002/ana.22687 . 3354734 . 370–84.
• Chen LQ, Hou BH, Lalonde S, Takanaga H, Hartung ML, Qu XQ, Guo WJ, Kim JG, Underwood W, Chaudhuri B, Chermak D, Antony G, White FF, Somerville SC, Mudgett MB, Frommer WB . Sugar transporters for intercellular exchange and nutrition of pathogens . Nature . 468 . 7323 . Nov 2010 . 21107422 . 10.1038/nature09606 . 527–32 . 3000469. 2010Natur.468..527C .
• Tagoh H, Kishi H, Muraguchi A . Molecular cloning and characterization of a novel stromal cell-derived cDNA encoding a protein that facilitates gene activation of recombination activating gene (RAG)-1 in human lymphoid progenitors . Biochemical and Biophysical Research Communications . 221 . 3 . Apr 1996 . 8630032 . 10.1006/bbrc.1996.0667 . 744–9.

Notes and References

1. Web site: Entrez Gene: Solute carrier family 50 (sugar efflux transporter), member 1 .
2. Feng L, Frommer WB . Structure and function of SemiSWEET and SWEET sugar transporters . Trends in Biochemical Sciences . 40 . 8 . 480–486 . 2015 . 26071195 . 10.1016/j.tibs.2015.05.005 . free .
3. Deng D, Yan N . GLUT, SGLT, and SWEET: Structural and mechanistic investigations of the glucose transporters . Protein Science . 25 . 3 . 546–558 . 2016 . 26650681 . 4815417 . 10.1002/pro.2858.
4. Lopdell TJ, Tiplady K, Struchalin M, Johnson TJ, Keehan M, Sherlock R, Couldrey C, Davis SR, Snell RG, Spelman RJ, Littlejohn MD . DNA and RNA-sequence based GWAS highlights membrane-transport genes as key modulators of milk lactose content . BMC Genomics . 18 . 968 . 2017 . 1 . 29246110 . 5731188 . 10.1186/s12864-017-4320-3 . free .
5. Hamada M, Wada S, Kobayashi K, Satoh N . Ci-Rga, a gene encoding an MtN3/saliva family transmembrane protein, is essential for tissue differentiation during embryogenesis of the ascidian Ciona intestinalis . Differentiation . 73 . 7 . 364–376 . 2005 . 16219040 . 10.1111/j.1432-0436.2005.00037.x .
6. Wright EM . Glucose transport families SLC5 and SLC50 . Molecular Aspects of Medicine . 34 . 2–3 . 183–196 . 2013 . 23506865 . 10.1016/j.mam.2012.11.002 .