Crystal structure of the human glucose transporter glut1. The healthy heart generates up to 30% of its atp from glucose. Erythritol reduces small intestinal glucose absorption, increases muscle glucose uptake, improves glucose metabolic enzymes activities and increases expression of glut4 and irs1 in type 2 diabetic rats. After a meal, glucose that is absorbed from the digestive system and circulates in the blood now stimulates the release of insulin from the pancreas figure 4. Pdf regulated transport of the glucose transporter glut4. Residues that are unique to glut4 are shown in red. Rab10 delivers glut4 storage vesicles to the plasma membrane. Erythritol reduces small intestinal glucose absorption. The full text of this article is available in pdf format. Each domain of the plasma membrane contributed equally to this effect.
Differential regulation of the glut1 and glut4 glucose transport systems by glucose and insulin in l6 muscle cells in culture received for publication, may 9, 1990. Pdf expression of glucose transporters glut 1 and glut. Each glucose transporter isoform plays a specific role in glucose metabolism determined by its pattern of tissue expression, substrate specificity, transport kinetics, and regulated expression in different physiological conditions. Glucose is transported into the heart by members of the family of facilitative glucose. Glut1 was the first glucose transporter to be characterized. Glucose transporter expression in the central nervous system. In contrast, the glut 1 protein content in these membranes decreased with glucose starvation and increased with insulin treatment. The structure of human glut1 in an inwardopen conformation is reported. This protein is found mainly in the kidneys, specifically in structures called proximal tubules. May 01, 20 the glucose transporter, glut4, redistributes to the plasma membrane pm upon insulin stimulation, but also recycles through endosomal compartments. This shorter version of glut9 reabsorbs urate into the bloodstream more readily than the full length version. Expression of glucose transporters glut1, glut3, glut9 and.
Glut 1 is encoded by the slc2 gene and is one of a family of 14 genes encoding glut proteins. To date, 14 members of the glutslc2 have been identified. Under conditions of cardiac injury or stress, the heart relies even more heavily on glucose as a source of fuel. Pdf glucose transporter expression in the central nervous. Glut4, intracellular traffic, translocation, regulated exocytosis, adipocyte. Glut4, glut1, and glut8 are the dominant glut transcripts. An approach to the hip through the anterior capsule via a lateral incision is described, which gives excellent access to the medullary canal of the upper femur and is, therefore, suitable for hip hemiarthroplasty. Exercise causes muscle glut4 translocation in an insulin. Class ii gluts 5, 7, 9 and 11 are fructose transporters.
The journal of biological chemistry 0 1991 by the american society for biochemistry and molecular biolow, inc. These structures help to reabsorb needed nutrients, water, and other materials into the blood and excrete unneeded substances into the urine. I understand that glut4 has a km similar to the concentration of glucose so it gets saturated fast but how come glucose influx can still occur if the glut4 receptors are. Glut1 sirna enhances radiosensitization of laryngeal cancer stem cells via enhanced dna damage, cell cycle redistribution, and promotion of apoptosis in vitro and in vivo. The slc2a9 gene provides instructions for making a protein called glucose transporter 9 glut9. Aug 24, 2015 more than a decade ago, ben bernanke famously argued that a ballooning u. The overriding question that drove the early work on glut3 was. Glucose transporters repositorio uc pontificia universidad. Different rab proteins control these transport itineraries of glut4.
It is a rare disease affecting between 3000 and 7000 people in the united states and is caused by a mutation of the slc2a1 gene. Dissociation of glut4 translocation and insulinstimulated. To date, 14 members of the glut slc2 have been identified. Glut4 controls glucose transport into fat and muscle tissues in response. The invitae glucose transporter type 1 deficiency syndrome test analyzes the slc2a1 gene, whose pathogenic variants cause glucose transporter type 1 deficiency syndrome glut1ds, which is associated with low glucose concentration in the cerebrospinal fluid. Transgluteal approach for hemiarthroplasty of the hip. Glucose transporter type 4 glut 4, also known as solute carrier family 2, facilitated glucose transporter member 4, is a protein encoded, in humans, by the slc2a4 gene. The heart derives energy from a wide variety of substrates including fatty acids, carbohydrates, ketones, and amino acids. Glut4 slc2a4 is the insulinresponding glucose transporter, found predominantly in muscle cells and adipocytes fat cells. The gluteus medius is split vertically and the anterior portion detached from the. A novel function of lactate transporter mct1 in gastric. A novel function of lactate transporter mct1 in gastric restitution lisamarrone underthedirectionof dr. Crystal structure of the human glucose transporter glut1 nature. Get a printable copy pdf file of the complete article 1.
As you well know, glut 4 is insulinregulated and its present only in skeletal and cardiac muscle, adipose tissue. Differential evolution with time and chronic insulin effect. Test invitae glucose transporter type 1 glut1 deficiency. Translocation of the glucose transporter glut4 in cardiac ncbi. Glut4 has long been known to be an insulin responsive glucose transporter. Glut4 is the primary glucose transporter responsible for insulin stimulated glucose uptake into muscle and adipose tissues. Regulation of glut4 has been a major focus of research on the cause and prevention of type 2 diabetes. The first evidence for this distinct glucose transport protein was provided by david james in 1988. It utilizes the principle that gluteus medius and vastus lateralis are in anatomical continuity. The integral membrane protein glut4 represents the acutely regulated glucose transporter of fat and muscle cells. Many car shoppers might not realize how much the new and usedcar markets feed off each other, says philip reed of. Glut2 glucose transporter 2 is a transmembrane protein that allows the movement of glucose in the cells of the liver, pancreas, kidneys and small intestine. Insulin stimulates glucose uptake by promoting the translocation of the glut4 isoform of glucose transporter to the plasma membrane. The glucose transporter, glut4, redistributes to the plasma membrane pm upon insulin stimulation, but also recycles through endosomal compartments.
Detection of glut mrnas in the left ventricle of c57bl6j mice. May 18, 2014 the glucose transporter glut1 catalyses facilitative diffusion of glucose into erythrocytes and is responsible for glucose supply to the brain and other organs. As you well know, glut4 is insulinregulated and its present only in skeletal and cardiac muscle, adipose tissue. Used car glut music to your ears if youre buying soon.
The first step is to install the development libraries of openglglut in ubuntu. Glucose transporter type 4 glut4, also known as solute carrier family 2, facilitated glucose transporter member 4, is a protein encoded, in humans, by the slc2a4 gene. Because glucose transport is a key component in insulin action, the overall objective here is to focus on the mechanisms by which nuclear transcription factors and their ligands i. An extremely good looking guy, who happens to be an enormous cunt. Apigenin inhibits the glut1 glucose transporter and the. Molecular mechanisms of glut4 regulation in adipocytes em. In the absence of insulin, glut 4 is largely excluded. Herbal antihyperglycemic compound increases expression of. Regulation of glut4 and insulindependent glucose flux. Myocardial ischemia results in the translocation of the glucose transporter proteins glut1 and glut4 to the sarcolemma.
Structure, function and consequences of deficiency. Glut1 ds interferes with the ability of glucosethe bodys primary energy sourceto cross the bloodbrain barrier. Glut4 is the insulinregulated glucose transporter found primarily in adipose tissues and striated muscle skeletal and cardiac. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. Imaging glut4 translocation to the plasma membrane. This transporter has a low affinity but a high capacity for transporting glucose, meaning that glucose will only be transported across the membrane when it is in high concentration inside a cell.
Glucose uptake in skeletal muscle is dependent on the translocation of glut4 glucose transporters to the plasma membrane. Understanding how insulin signaling alters the intracellular trafficking of glut4 as well as understanding the fate of glucose transported into the cell by glut4 will be critically important for seeking solutions to. Expression of glucose transporters glut 1, glut 3, glut 9 and hif1 in normal and degenerate human intervertebral disc. Glucose transporter translocation because insulinstimulated glucose transport in skeletal muscle is mediated by glut4 26, 28, and there is a normal level of total glut4 protein expressed in the muscles of the glut1 transgenic mice, we examined the possibility that glut4 translocation in insulinstimulated muscle is defective in the glut1. Expression of glucose transporters glut 1 and glut 4 in primary cultured rat adipocytes.
The altered activity of the fructose transporter glut5, an isoform of the facilitateddiffusion glucose transporter family, has been linked to disorders such. The diagram shows a homology plot between glut1 and glut4. Responses of glut4deficient hearts to ischemia underscore the. Materials and methods human tissues for realtime pcr study. Using cut 4 specific antisera, we and our colleagues examine d the distribution of glut 4 in adipose tissue and in muscle using immunogold electron microscopy s fig. Falling used car prices, brought on by a glut of vehicles hitting the usedcar market, may be music to your ears if youre buying, says. Glut1 ds stands for glucose transporter type1 deficiency syndrome. The typical insulin responsive glut transporter isoform was. In this study, we evaluated the effects of the flavonoid apigenin on glucose uptake, on the expression of the glucose transporter 1 glut 1, and on the phosphoinositide 3kinase pi3kakt pathway in human pancreatic cancer cells. Expression of glucose transporters glut1, glut3, glut9 and hif1 in normal and degenerate human intervertebral disc. Expression of glucose transporters glut1, glut3, glut9.
Glut4 facilitates insulin stimulation and campmediated inhibition. Glunts are usually people who know how attractive they are, therefore feel they are entitled to act like douchebags. Objectives the antiproliferative mechanisms of flavonoid drugs inpancreatic cancer cells remain unclear. More than a decade ago, ben bernanke famously argued that a ballooning u. A pcr was employed to identify each known murine member of the facilitative glucose transporter family in the left ventricle of 10weekold male c57bl6j mice. How come glut2 is said to be insulin independent if it senses the release of insulin to store glut2 in hepatocytes. The glucose transporter isoform glut4 is found only in cells that exhibit. Glut 1 of humans and mice have 98% identity at the amino acid level. Glut4positive, clathrincoated pits were also present at each cell surface domain.
Carnitine palmitoyltransferase1 cpt1 is thought to be the ratelimiting enzyme in fao and is inhibited by malonylcoa. We have been able to follow glut4 movements in living cells using timelapse confocal microscopy. Glut 4 and glut 1 proteins in the plasma mem brane. This insulin is the signal for a rapid transfer of glut4 in muscle and adipose cells to the cell membranes.
View pdf in oncotargets and therapy on 7 december 2019 by zhong, j. In this study, we evaluated the effects of the flavonoid apigenin on glucose uptake, on the expression of the glucose transporter 1 glut1, and on the phosphoinositide 3kinase pi3kakt pathway in human pancreatic cancer cells. Glut1 belongs to the facilitative glucose transport protein family that comprises members. Slc2a7 does not transport galactose, 2deoxydglucose or xylose.
883 564 306 797 1238 310 83 610 1606 817 85 896 170 235 1493 1385 660 1622 982 856 1384 1045 1418 950 99 757 1096 1552 601 956 1565 938 1323 674 1441 150 805 881 659 289 351 923 767 38 1445 431 247 1341 96