Is GLUT4 insulin dependent?
GLUT4 is an insulin-regulated glucose transporter that is responsible for insulin-regulated glucose uptake into fat and muscle cells. In the absence of insulin, GLUT4 is mainly found in intracellular vesicles referred to as GLUT4 storage vesicles (GSVs).
Why is GLUT4 insulin dependent?
GLUT4 functions for the insulin-dependent translocation of glucose. Thus, insulin stimulates the uptake of glucose by GLUT4 in the muscle cell where hexokinase converts it to glucose-6-phosphate so that the cell may utilize it for either glycolysis for energy or for the formation of glycogen when glucose is abundant.
What is flotillin?
Flotillins, which are proteins that localize to specific microdomains or lipid rafts in the plasma membrane, mediate a clathrin-independent endocytosis pathway that is regulated by the Src family tyrosine kinase Fyn [1], [2].
Which glut is insulin independent?
GLUT1 is insulin-independent and is widely distributed in different tissues. GLUT4 is insulin-dependent and is responsible for the majority of glucose transport into muscle and adipose cells in anabolic conditions.
What is the role of caveolin?
The caveolin proteins (caveolin-1, -2, and -3) serve as the structural components of caveolae, while also functioning as scaffolding proteins, capable of recruiting numerous signaling molecules to caveolae, as well as regulating their activity.
Does skeletal muscle have Caveolae?
Caveolae are extremely abundant in adipocytes, skeletal muscle cells, endothelia, and fibroblasts but undetectable in some other cell types. Caveolae are generally classified as uncoated structures as they do not possess the prominent coat structure characteristic of clathrin-coated pits.
Is GLUT3 insulin-dependent?
In other cells and tissues, glucose uptake is mainly provided by the transporters GLUT1 and GLUT3 or by other special, not yet specified, transporters of the GLUT family. These transporters function independent of insulin.
Is GLUT2 insulin-dependent?
GLUT4 is an insulin-dependent GLUT (Brosius et al., 1992; Cooper et al., 1993; Standley and Rose, 1994; Kahn et al., 1995; Banz et al., 1996) whereas GLUT2 is, in contrast, an insulin-independent transporter (Pyla et al., 2013).
Is GLUT2 insulin dependent?
It is the principal transporter for transfer of glucose between liver and blood Unlike GLUT4, it does not rely on insulin for facilitated diffusion.
What is Caveolae in smooth muscle?
Caveolae are flask-shaped invaginations of the plasma membrane that are abundant features of smooth muscle.
Is Flotillin-1 palmitoylation independent of IGF-1 stimulation?
(C) Palmitoylation of newly synthesized flotillin-1 occurs independently of IGF-1 stimulation. HEK293T cells were treated with 100 μM 2-BP and 50 µM CHX for 15 h, rinsed, and chased for the indicated times in serum-free medium (control) or 10 nM IGF-1-containing medium (IGF-1) and subjected to FAE analysis.
Is there a role for Flotillin-1 in the intracellular growth of chlamydial inclusion?
Although the molecular function of flotillin-1 in chlamydial inclusion remains to be elucidated, our findings suggest a role for flotillin-1 in the intracellular growth of C. pneumoniae. ACKNOWLEDGMENTS
What is Flotillin-1 (reggie-2) (flotillin)?
Flotillin-1 (also known as reggie-2) and flotillin-2 (also known as reggie-1) are membrane-associated oligomeric proteins that are ubiquitously expressed ( Lang et al., 1998; Neumann-Giesen et al., 2004; Solis et al., 2007; Stuermer et al., 2001 ).
How are Reggie/flotillin proteins organized in membrane microdomains?
Reggie/flotillin proteins are organized into stable tetramers in membrane microdomains. Biochem. J.403:313–322 [PMC free article][PubMed] [Google Scholar] 58. Stuermer CA. 2011. Reggie/flotillin and the targeted delivery of cargo. J. Neurochem.116:708–713 [PubMed] [Google Scholar] 59. Stuermer CA, et al. 2001.