Human SLC2A4 (Glucose Transporter GLUT4) knockout HeLa cell lysate

Supplementary info

This supplementary information is collated from multiple sources and compiled automatically.

Activity summary

Glucose transporter GLUT4 also known as GLUT-4 or GLUT 4 transporter plays an important role in glucose uptake in cells. It is an insulin-responsive class I facilitated glucose transporter. GLUT4 predominantly expresses in insulin-sensitive tissues such as adipose tissue and skeletal and cardiac muscles. The functional transport mechanism facilitates glucose entry into the cell by translocating from intracellular vesicles to the plasma membrane in response to insulin stimulation. The molecular weight of GLUT4 is about 50 kDa and this property is often observed in techniques such as GLUT4 western blot where it aids in the identification of the transporter.

Biological function summary

GLUT4 helps regulate blood sugar levels through its control over glucose uptake in muscle and adipose tissues. As an important component of the insulin-regulated glucose transport system GLUT4 responds to increased insulin levels by moving to the cell's surface aiding in glucose transportation into the cell. This adaptive response reduces blood glucose concentration after food intake. GLUT4 operates largely independently but may interact with other glucose transporters like GLUT1 to maintain normal cellular glucose homeostasis.

Pathways

GLUT4 plays a significant role in the insulin signaling pathway and glucose homeostasis. Activation of the insulin receptor triggers a signaling cascade that includes enzymes like Akt (protein kinase B) which facilitates the translocation of GLUT4 vesicles to the plasma membrane. This translocation is important for glucose entry into the cells. Other key proteins in this pathway include IRS (insulin receptor substrate) proteins which act as signaling intermediates to link insulin receptor activation to downstream targets like GLUT4. Its activity is central to the maintenance of energy balance and storage in the body.

Associated diseases and disorders

GLUT4 is closely associated with conditions like type 2 diabetes and obesity. Impaired GLUT4 function or expression can lead to decreased insulin sensitivity and glucose uptake contributing to the hyperglycemic state found in type 2 diabetes. Additionally obesity often presents a parallel decline in GLUT4 activity exacerbating insulin resistance. The regulation of GLUT4 is influenced by proteins such as insulin receptor and IRS proteins which when dysfunctional contribute to the pathogenesis of these metabolic disorders.