Glucose transporter type 8, a Class 3 GLUT, of the Major Facilitator Superfamily of transporters
Glucose transporter type 8 (GLUT8) is also called Solute carrier family 2, facilitated glucose transporter member 8 (SLC2A8) or glucose transporter type X1 (GLUTX1). It is classified as a Class 3 GLUT protein and is an insulin-regulated facilitative glucose transporter predominantly expressed in testis and brain. It can also transport fructose and galactose. SLC2A8 knockout mice were viable, developed normally, and display only a very mild phenotype, including mild alterations in the brain (increased proliferation of hippocampal neurons), heart (impaired transmission of electrical wave through the atrium), and sperm cells (reduced number of motile sperm cells). GLUT proteins are comprised of about 500 amino acid residues, possess a single N-linked oligosaccharide, and have 12 transmembrane segments. They belong to the Glucose transporter -like (GLUT-like) family of the Major Facilitator Superfamily (MFS) of membrane transport proteins. MFS proteins are thought to function through a single substrate binding site, alternating-access mechanism involving a rocker-switch type of movement.
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