Overview
- Peptide (C)KPSTELEYLGPDE, corresponding to amino acid residues 495-507 of human Glucose Transporter 4 (Accession P14672). Intracellular, C-terminus.
- Rat brain sections (1:40).
Expression of Glucose Transporter 4 in rat olfactory bulbImmunohistochemical staining of rat olfactory bulb free floating frozen sections using Anti-GLUT4-ATTO Fluor-594 Antibody (#AGT-024-AR), (1:40). GLUT4 immunoreactivity (red) is strongly detected in some glomeruli (vertical arrows). Lower immunoreactivity in other glomeruli (horizontal arrows) is also observed. Nuclei are stained using DAPI as the counterstain.
The GLUT protein family is a member of the major facilitator superfamily of membrane transporters and is encoded by the SLC2 genes. GLUT proteins contain 12 membrane-spanning domains, an N-linked glycosylation site, and intracellular NH2 and COOH termini. In addition, there are several conserved residues and motifs designated “sugar transporter signatures”.
To date, 14 GLUT isoforms have been identified and divided into 3 different classes based on sequence similarity and structural and functional characteristics. GLUT4 together with GLUT 1-3 and 14 belong to Class I.
GLUT4 is an insulin-regulated glucose transporter responsible for insulin-regulated glucose uptake into fat and muscle cells. GLUT4 translocates from intracellular stores to the cell surface, from an inactive site to an active one in order to enhance glucose uptake1.
GLUT4 is expressed mainly in adipose tissue and skeletal muscle. It is also detected in brain, kidney and intestine.
There is no evidence for mutation in GLUT4 that is linked to metabolic disease in humans. However, GLUT4 polymorphisms are rare and equally common in normoglycaemic individuals and type 2 diabetics. General decrease in GLUT4 levels show signs of diabetes, while a disruption in GLUT4 expression in muscle or adipose tissue might contribute to the development of whole-body insulin resistance in humans2.
