What causes translocation of GLUT4?
GLUT4 is present in vesicles in cytoplasm of the cells. Binding of insulin to insulin receptor causes translocation of GLUT4 to cell membrane. GLUT4 vesicles in the skeletal muscle are either transferrin positive or negative and are translocated by different stimuli.
What is the mechanism used to transport glucose?
The GLUTs transport glucose across the plasma membrane by means of a facilitated diffusion mechanism.
How glucose enters the cell GLUT4?
Glucose enters the muscle cell via facilitated diffusion through the GLUT4 glucose transporter which translocates from intracellular storage depots to the plasma membrane and T-tubules upon muscle contraction.
Can GLUT4 work without insulin?
In the absence of insulin (basal), a pool of GLUT4 is targeted to GSVs, which are derived from the TGN and/or endosomes. In the presence of insulin, these GSVs fuse directly with the plasma membrane in an initial burst (insulin burst).
What is GLUT4 translocation?
Insulin stimulates glucose uptake by altering the subcellular distribution of glucose transporter 4 (Glut4) from intracellular stores to the plasma membrane, a process known as Glut4 translocation (1, 2). Defects in this process are observed in insulin resistance, type II diabetes mellitus, and metabolic syndrome.
What is the function of GLUT4?
Skeletal muscle both stores glucose as glycogen and oxidizes it to produce energy following the transport step. The principal glucose transporter protein that mediates this uptake is GLUT4, which plays a key role in regulating whole body glucose homeostasis.
What happens to GLUT4 without insulin?
In the absence of insulin, the majority of GLUT4 is stored in small intracellular vesicles [referred to as GLUT4 storage vesicles (GSVs) (Martin et al., 1998) or insulin responsive vesicles (IRVs) (Kupriyanova et al., 2002)].
What does the GLUT4 do?
GLUT4 is an insulin-regulated glucose transporter that is responsible for insulin-regulated glucose uptake into fat and muscle cells.