Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Rat glucokinase gene: structure and regulation by insulin.

ABSTRACT: The glucokinase gene is 15.5-kilobases long, appears to be present as a single copy, and contains 10 exons that range in size from 96 to 977 base pairs. The transcription start site was located 127 nucleotides upstream from the translation initiation codon. The 5' flanking DNA contains several regions similar to defined promoter elements. These include a probable "TATA box," an Sp1 binding site, and several elements related to liver-specific gene expression. In addition, we determined that transcription of the glucokinase gene increased at least 20-fold when diabetic rats were treated with insulin for 2 hr.

SUBMITTER: Magnuson MA

PROVIDER: S-EPMC297510 | biostudies-other | 1989 Jul

REPOSITORIES: biostudies-other

ACCESS DATA

Json Xml

Publications

Rat glucokinase gene: structure and regulation by insulin.

Magnuson M A MA Andreone T L TL Printz R L RL Koch S S Granner D K DK

Proceedings of the National Academy of Sciences of the United States of America 19890701 13

The glucokinase gene is 15.5-kilobases long, appears to be present as a single copy, and contains 10 exons that range in size from 96 to 977 base pairs. The transcription start site was located 127 nucleotides upstream from the translation initiation codon. The 5' flanking DNA contains several regions similar to defined promoter elements. These include a probable "TATA box," an Sp1 binding site, and several elements related to liver-specific gene expression. In addition, we determined that trans ...[more]

PMID: 2662183

Similar Datasets

Dairy Product Consumption Interacts with Glucokinase (GCK) Gene Polymorphisms Associated with Insulin Resistance.

Project description:Dairy product intake and a person's genetic background have been reported to be associated with the risk of type 2 diabetes (T2D). The objective of this study was to examine the interaction between dairy products and genes related to T2D on glucose-insulin homeostasis parameters. A validated food frequency questionnaire, fasting blood samples, and glucokinase (GCK) genotypes were analyzed in 210 healthy participants. An interaction between rs1799884 in GCK and dairy intake on the homeostasis model assessment of insulin resistance was identified. Secondly, human hepatocellular carcinoma cells (HepG2) were grown in a high-glucose medium and incubated with either 1-dairy proteins: whey, caseins, and a mixture of whey and casein; and 2-four amino acids (AA) or mixtures of AA. The expression of GCK-related genes insulin receptor substrate-1 (IRS-1) and fatty acid synthase (FASN) was increased with whey protein isolate or hydrolysate. Individually, leucine increased IRS-1 expression, whereas isoleucine and valine decreased FASN expression. A branched-chain AA mixture decreased IRS-1 and FASN expression. In conclusion, carriers of the A allele for rs1799884 in the GCK gene may benefit from a higher intake of dairy products to maintain optimal insulin sensitivity. Moreover, the results show that whey proteins affect the expression of genes related to glucose metabolism.

| S-EPMC5618154 | biostudies-literature

Treatment of diabetes and long-term survival after insulin and glucokinase gene therapy.

Project description:Diabetes is associated with severe secondary complications, largely caused by poor glycemic control. Treatment with exogenous insulin fails to prevent these complications completely, leading to significant morbidity and mortality. We previously demonstrated that it is possible to generate a "glucose sensor" in skeletal muscle through coexpression of glucokinase and insulin, increasing glucose uptake and correcting hyperglycemia in diabetic mice. Here, we demonstrate long-term efficacy of this approach in a large animal model of diabetes. A one-time intramuscular administration of adeno-associated viral vectors of serotype 1 encoding for glucokinase and insulin in diabetic dogs resulted in normalization of fasting glycemia, accelerated disposal of glucose after oral challenge, and no episodes of hypoglycemia during exercise for >4 years after gene transfer. This was associated with recovery of body weight, reduced glycosylated plasma proteins levels, and long-term survival without secondary complications. Conversely, exogenous insulin or gene transfer for insulin or glucokinase alone failed to achieve complete correction of diabetes, indicating that the synergistic action of insulin and glucokinase is needed for full therapeutic effect. This study provides the first proof-of-concept in a large animal model for a gene transfer approach to treat diabetes.

| S-EPMC3636629 | biostudies-literature

Structural basis for regulation of human glucokinase by glucokinase regulatory protein.

Project description:Glucokinase (GCK) is responsible for maintaining glucose homeostasis in the human body. Dysfunction or misregulation of GCK causes hyperinsulinemia, hypertriglyceridemia, and type 2 diabetes. In the liver, GCK is regulated by interaction with the glucokinase regulatory protein (GKRP), a 68 kDa polypeptide that functions as a competitive inhibitor of glucose binding to GCK. Formation of the mammalian GCK-GKRP complex is stimulated by fructose 6-phosphate and antagonized by fructose 1-phosphate. Here we report the crystal structure of the mammalian GCK-GKRP complex in the presence of fructose 6-phosphate at a resolution of 3.50 Å. The interaction interface, which totals 2060 Å(2) of buried surface area, is characterized by a small number of polar contacts and substantial hydrophobic interactions. The structure of the complex reveals the molecular basis of disease states associated with impaired regulation of GCK by GKRP. It also offers insight into the modulation of complex stability by sugar phosphates. The atomic description of the mammalian GCK-GKRP complex provides a framework for the development of novel diabetes therapeutic agents that disrupt this critical macromolecular regulatory unit.

| S-EPMC3859847 | biostudies-literature

A glucokinase gene mutation in a young boy with diabetes mellitus, hyperinsulinemia, and insulin resistance.

Project description:We report the case of a 12-year-old boy with a glucokinase (GCK) mutation, and diabetes with hyperinsulinemia and insulin resistance. For 4 years, the patient intermittently received insulin medications Actrapid HM and Protaphane HM (total dose 5 U/day), with glycated hemoglobin (HbA1c) levels of 6.6%-7.0%. After extensive screening the patient was found to carry a heterozygous mutation (p.E256K) in GCK (MIM #138079, reference sequence NM_000162.3). Insulin therapy was replaced by metformin at 1,700 mg/day. One year later, his HbA1c level was 6.9%, postprandial glycemia at 120 min of oral glucose tolerance test was 15.4 mmol/L, hyperinsulinemia had increased to 508.9 mU/L, homeostasis model assessment index was 114.2 and the Matsuda index was 0.15. Insulin resistance was confirmed by a hyperinsulinemic euglycemic clamp test - M-index was 2.85 mg/kg/min. This observation is a rare case of one of the clinical variants of diabetes, which should be taken into account by a vigilant endocrinologist due to the need for nonstandard diagnostic and therapeutic approaches.

| S-EPMC5348075 | biostudies-literature

Glucokinase links Kruppel-like factor 6 to the regulation of hepatic insulin sensitivity in nonalcoholic fatty liver disease.

Project description:The polymorphism, KLF6-IVS1-27A, in the Krüppel-like factor 6 (KLF6) transcription factor gene enhances its splicing into antagonistic isoforms and is associated with delayed histological progression of nonalcoholic fatty liver disease (NAFLD). To explore a potential role for KLF6 in the development of insulin resistance, central to NAFLD pathogenesis, we genotyped KLF6-IVS1-27 in healthy subjects and assayed fasting plasma glucose (FPG) and insulin sensitivities. Furthermore, we quantified messenger RNA (mRNA) expression of KLF6 and glucokinase (GCK), as an important mediator of insulin sensitivity, in human livers and in liver tissues derived from a murine Klf6 knockdown model (DeltaKlf6). Klf6 overexpression studies in a mouse hepatocyte line were utilized to mechanistically link KLF6 with Gck promoter activity. KLF6-IVS1-27Gwt (i.e., less KLF6 splicing) was associated with stepwise increases in FPG and insulin and reduced hepatic insulin sensitivity. KLF6 binds to the liver-specific Gck promoter and activates a GCK promoter-reporter, identifying GCK as a KLF6 direct transcriptional target. Accordingly, in DeltaKlf6 hepatocytes Gck expression was reduced and stable transfection of Klf6 led to up-regulation of Gck. GCK and KLF6 mRNAs correlate directly in human NAFLD tissues and immunohistochemistry studies confirm falling levels of both KLF6 and GCK in fat-laden hepatocytes. In contrast to full-length KLF6, splice variant KLF6-SV1 increases in NAFLD hepatocytes and inversely correlates with glucokinase regulatory protein, which negatively regulates GCK activity.KLF6 regulation of GCK contributes to the development of hepatic insulin resistance. The KLF6-IVS1-27A polymorphism, which generates more KLF6-SV1, combats this, lowering hepatic insulin resistance and blood glucose.

| S-EPMC3295906 | biostudies-literature

Homotropic allosteric regulation in monomeric mammalian glucokinase.

Project description:Glucokinase catalyzes the ATP-dependent phosphorylation of glucose, a chemical transformation that represents the rate-limiting step of glycolytic metabolism in the liver and pancreas. Glucokinase is a central regulator of glucose homeostasis as evidenced by its association with two disease states, maturity onset diabetes of the young (MODY) and persistent hyperinsulinemia of infancy (PHHI). Mammalian glucokinase is subject to homotropic allosteric regulation by glucose-the steady-state velocity of glucose-6-phosphate production is not hyperbolic, but instead displays a sigmoidal response to increasing glucose concentrations. The positive cooperativity displayed by glucokinase is intriguing since the enzyme functions as a monomer under physiological conditions and contains only a single binding site for glucose. Despite the existence of several models of kinetic cooperativity in monomeric enzymes, a consensus has yet to be reached regarding the mechanism of allosteric regulation in glucokinase. Experimental evidence collected over the last 45 years by a number of investigators supports a link between cooperativity and slow conformational reorganizations of the glucokinase scaffold. In this review, we summarize advances in our understanding of glucokinase allosteric regulation resulting from recent X-ray crystallographic, pre-equilibrium kinetic and high-resolution nuclear magnetic resonance investigations. We conclude with a brief discussion of unanswered questions regarding the mechanistic basis of kinetic cooperativity in mammalian glucokinase.

| S-EPMC3294010 | biostudies-literature

Crystal Structure of Kluyveromyces lactis Glucokinase (KlGlk1).

Project description:Glucose phosphorylating enzymes are crucial in the regulation of basic cellular processes, including metabolism and gene expression. Glucokinases and hexokinases provide a pool of phosphorylated glucose in an adenosine diphosphate (ADP)- and ATP-dependent manner to shape the cell metabolism. The glucose processing enzymes from Kluyveromyces lactis are poorly characterized despite the emerging contribution of this yeast strain to industrial and laboratory scale biotechnology. The first reports on K. lactis glucokinase (KlGlk1) positioned the enzyme as an essential component required for glucose signaling. Nevertheless, no biochemical and structural information was available until now. Here, we present the first crystal structure of KlGlk1 together with biochemical characterization, including substrate specificity and enzyme kinetics. Additionally, comparative analysis of the presented structure and the prior structures of lactis hexokinase (KlHxk1) demonstrates the potential transitions between open and closed enzyme conformations upon ligand binding.

| S-EPMC6801647 | biostudies-literature

Hypothalamic arcuate nucleus glucokinase regulates insulin secretion and glucose homeostasis.

Project description:AimsTo investigate the role of arcuate glucokinase (GK) in the regulation of glucose homeostasis.Materials and methodsA recombinant adeno-associated virus expressing either GK or an antisense GK construct was used to alter GK activity specifically in the hypothalamic arcuate nucleus (arc). GK activity in this nucleus was also increased by stereotactic injection of the GK activator, compound A. The effect of altered arc GK activity on glucose homeostasis was subsequently investigated using glucose and insulin tolerance tests.ResultsIncreased GK activity specifically within the arc increased insulin secretion and improved glucose tolerance in rats during oral glucose tolerance tests. Decreased GK activity in this nucleus reduced insulin secretion and increased glucose levels during the same tests. Insulin sensitivity was not affected in either case. The effect of arc GK was maintained in a model of type 2 diabetes.ConclusionsThese results demonstrate a role for arc GK in systemic glucose homeostasis.

| S-EPMC6099255 | biostudies-literature

Structure, function, and regulation of insulin-degrading enzyme.

Project description:The short half-life of insulin in the human body (4-6 min) prompted the search and discovery of insulin-degrading enzyme (IDE), a 110-kDa metalloprotease that can rapidly degrade insulin into inactive fragments. Genetic and biochemical evidence accumulated in the last sixty years has implicated IDE as an important physiological contributor in the maintenance of insulin levels. Recent structural and biochemical analyses reveal the molecular basis of how IDE uses size and charge distribution of the catalytic chamber and structural flexibility of substrates to selectively recognize and degrade insulin, as well as the regulatory mechanisms of this enzyme. These studies provide a path for potential therapeutics in the control of insulin metabolism by the degradation of insulin.

| S-EPMC3656499 | biostudies-literature

Insulin-receptor substrate-2 (irs-2) is required for maintaining glucokinase and glucokinase regulatory protein expression in mouse liver.

Project description:Insulin receptor substrate (IRS) proteins play important roles in hepatic nutrient homeostasis. Since glucokinase (GK) and glucokinase regulatory protein (GKRP) function as key glucose sensors, we have investigated the expression of GK and GKRP in liver of Irs-2 deficient mice and Irs2(-/-) mice where Irs2 was reintroduced specifically into pancreatic ?-cells [RIP-Irs-2/IRS-2(-/-)]. We observed that liver GK activity was significantly lower (p<0.0001) in IRS-2(-/-) mice. However, in RIP-Irs-2/IRS-2(-/-) mice, GK activity was similar to the values observed in wild-type animals. GK activity in hypothalamus was not altered in IRS-2(-/-) mice. GK and GKRP mRNA levels in liver of IRS-2(-/-) were significantly lower, whereas in RIP-Irs-2/IRS-2(-/-) mice, both GK and GKRP mRNAs levels were comparable to wild-type animals. At the protein level, the liver content of GK was reduced in IRS-2(-/-) mice as compared with controls, although GKRP levels were similar between these experimental models. Both GK and GKRP levels were lower in RIP-Irs-2/IRS-2(-/-) mice. These results suggest that IRS-2 signalling is important for maintaining the activity of liver GK. Moreover, the differences between liver and brain GK may be explained by the fact that expression of hepatic, but not brain, GK is controlled by insulin. GK activity was restored by the ?-cell compensation in the RIP-Irs-2/IRS-2 mice. Interestingly, GK and GKRP protein expression remained low in RIP-Irs-2/IRS-2(-/-) mice, perhaps reflecting different mRNA half-lives or alterations in the process of translation and post-translational regulation.

| S-EPMC3613347 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data