Glucose transporter 1 (GLUT1
) or solute carrier family 2 (SLC2A1) is a member of the GLUT family of monosaccharides and polyols transporters. GLUT proteins transport glucose across cellular membranes through facilitative mechanisms and play a key role in glucose homeostasis (1). Fourteen GLUT proteins have been identified in the human, which are encoded by SLC2A genes 1-14 and are broadly expressed in many cell types and tissues. GLUT family members differ in sequence homology, substrate specificity and expression patterns. Based on sequence homology, GLUT family members are classified into Class I (GLUT1, 2
, and GLUT14), Class II (GLUT5
, and 11
), and Class III (GLUT6
and 13) (1). Structurally, GLUT transporters are integral membrane glycoproteins consisting of 12 membrane spanning helical domains, a single N-linked glycosylation site, and having cytoplasmic facing carboxy and amino terminal domains (2).
GLUT1 (Human glycosylated form theoretical molecular weight 55kDa) functions primarily as a glucose transporter but can transport other substrates including mannose, galactose and glucosamine across the membrane (3). Like other GLUT family members, GLUT1 is broadly expressed, nevertheless it is the predominant glucose transporter expressed in red blood cells and brain endothelial cells
(1). SLC2A1 mutations underscore the autosomal dominant disorder GLUT1 deficiency syndrome (GLUTI-DS) which is characterized by low glucose levels in the brain or hypoglycorrhachia due to insufficient glucose transport across the blood brain barrier (2, 4, 5). Phenotypically, GLUT1-DS is characterized by early onset seizures, neurologic developmental
delay, microcephaly, and ataxia (4). GLUT1 is highly expressed in the endothelium of cutaneous vascular lesions and serves as a marker for the diagnosis of juvenile or infantile hemangiomas (6).
1. Augustin, R. (2010). The protein family of glucose transport facilitators: It's not only about glucose after all. IUBMB Life. https://doi.org/10.1002/iub.315
2. Mueckler, M., & Thorens, B. (2013). The SLC2 (GLUT) family of membrane transporters. Molecular Aspects of Medicine. https://doi.org/10.1016/j.mam.2012.07.001
3. Stein, W. D., & Litman, T. (2015). Carrier-Mediated Transport. In Channels, Carriers, and Pumps. https://doi.org/10.1016/b978-0-12-416579-3.00004-6
4. Pearson, T. S., Akman, C., Hinton, V. J., Engelstad, K., & De Vivo, D. C. (2013). Phenotypic spectrum of glucose transporter type 1 deficiency syndrome (Glut1 DS). Current Neurology and Neuroscience Reports. https://doi.org/10.1007/s11910-013-0342-7
5. Messana, T., Russo, A., Vergaro, R., Boni, A., Santucci, M., & Pini, A. (2018). Glucose transporter type 1 deficiency syndrome: Developmental delay and early-onset ataxia in a novel mutation of the SLC2A1 gene. Journal of Pediatric Neurosciences. https://doi.org/10.4103/JPN.JPN_169_17
6. van Vugt, L. J., van der Vleuten, C. J. M., Flucke, U., & Blokx, W. A. M. (2017). The utility of GLUT1 as a diagnostic marker in cutaneous vascular anomalies: A review of literature and recommendations for daily practice. Pathology Research and Practice. https://doi.org/10.1016/j.prp.2017.04.023