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Insulin Mrna Sequence

Recombinant Dna Technology In The Synthesis Of Human Insulin

Recombinant Dna Technology In The Synthesis Of Human Insulin

Recombinant DNA Technology in the Synthesis of Human Insulin The nature and purpose of synthesising human insulin. Since Banting and Best discovered the hormone, insulin in 1921.(1) diabetic patients, whose elevated sugar levels (see fig. 1) are due to impaired insulin production, have been treated with insulin derived from the pancreas glands of abattoir animals. The hormone, produced and secreted by the beta cells of the pancreas' islets of Langerhans,(2) regulates the use and storage of food, particularly carbohydrates. Fig. 1 Fluctuations in diabetic person's blood glucose levels, compared with healthy individuals. Source: Hillson,R. - Diabetes: A beyond basics guide, pg.16. Although bovine and porcine insulin are similar to human insulin, their composition is slightly different. Consequently, a number of patients' immune systems produce antibodies against it, neutralising its actions and resulting in inflammatory responses at injection sites. Added to these adverse effects of bovine and porcine insulin, were fears of long term complications ensuing from the regular injection of a foreign substance,(3) as well as a projected decline in the production of animal derived insulin.(4) These factors led researchers to consider synthesising Humulin by inserting the insulin gene into a suitable vector, the E. coli bacterial cell, to produce an insulin that is chemically identical to its naturally produced counterpart. This has been achieved using Recombinant DNA technology. This method (see fig. 2) is a more reliable and sustainable(5) method than extracting and purifying the abattoir by-product. Fig. 2 An overview of the recombination process. Source: Novo - Nordisk promotional brochure,pg 6. Understanding the genetics involved. The structure of insulin. Chemically, insuli Continue reading >>

Cloning The Human Insulin Gene, Walter Gilbert

Cloning The Human Insulin Gene, Walter Gilbert

Description: Interviewee: Walter Gilbert. The recombinant DNA moratorium meant Gilbert had to go to England's Porton Down facility to try and isolate human insulin. He only had one chance ... (DNAi Location: Manipulation > Production > Players > Walter Gilbert > It wasn't human insulin) Transcript: We were trying to identify a fragment of DNA corresponding to a human insulin gene, it's actually a DNA copy of an insulin RNA, and we have a human insulin of a tumor, human tumor that makes insulin, which we thought we could take the RNA from, make a copy, identify a piece that would actually be the human insulin sequence. We could identify that by interacting that piece with a fragment of the rat insulin gene, which we already knew and use that as a tag, because the two genes have very, very similar sequences. We went through all the procedure, we run the material on what's called gel electrophoresis, moving up to a jelly-like material between glass plates, and we found what we thought was the human insulin gene. When we got back home we discovered that what we had actually isolated was the same rat insulin gene we had started with, that the gel plates we had brought, the glass plates, were contaminated with rat insulin from earlier experiments done here that had, we had actually by these very, very sensitive techniques been able to re-isolate essentially contaminant, the contaminating material rather than the material we wanted to find. Keywords: human insulin gene,rat insulin,porton down,gene walter,dna copy,gel electrophoresis,walter gilbert,recombinant dna,sensitive techniques,dnai,glass plates,human tumor,interviewee,rna,moratorium,fragment,genes,sequences,manipulation,england Downloads: MPEG 4 Video Theora Video Continue reading >>

Insulin Synthesis

Insulin Synthesis

Insulin is synthesized in significant quantities only in beta cells in the pancreas. Since it is a protein or a polypeptide structure it is synthesized like most other proteins via transcription and translation of DNA into mRNA and amino acid chains or polypeptide chains. Thereafter the protein undergoes structural changes to achieve its final form. Steps in insulin synthesis The insulin mRNA is translated as a single chain precursor called preproinsulin. Thereafter the removal of its signal peptide during insertion into the endoplasmic reticulum generates proinsulin. Proinsulin consists of three domains: an amino-terminal B chain a carboxy-terminal A chain a connecting peptide in the middle known as the C peptide In the endoplasmic reticulum the proinsulin is exposed to several specific endopeptidases which excise the C peptide. This forms the mature form of insulin. Insulin and free C peptide are packed in the Golgi bodies into secretory granules which accumulate in the cytoplasm. Secretion of insulin When the beta cell is appropriately stimulated, insulin is secreted from the cell by exocytosis. The insulin then diffuses into small blood vessels of the pancreas. C peptide is also secreted into blood, but has no known biological activity. Regulation of insulin synthesis Insulin synthesis is regulated by several mechanisms. These include: Regulation at the transcription from the insulin gene to mRNA formation Stability of the formed mRNA Regulation at the translation of the mRNA to polypeptide chains Regulation at the posttranslational modifications and quaternary structure formation Regulation of insulin secretion Insulin is secreted in primarily in response to elevated blood concentrations of glucose. Thus insulin is secreted as the body detects high blood glucose an Continue reading >>

Lilly's Rdna Insulin

Lilly's Rdna Insulin

Recombinant DNA Technology in the Synthesis of Human Insulin The nature and purpose of synthesising human insulin. Since Banting and Best discovered the hormone, insulin in 1921. (1) diabetic patients, whose elevated sugar levels (see fig. 1) are due to impaired insulin production, have been treated with insulin derived from the pancreas glands of abattoir animals. The hormone, produced and secreted by the beta cells of the pancreas' islets of Langerhans, (2) regulates the use and storage of food, particularly carbohydrates. Fluctuations in diabetic person's blood glucose levels, compared with healthy individuals. Source: Hillson,R. - Diabetes: A beyond basics guide, pg.16. Although bovine and porcine insulin are similar to human insulin, their composition is slightly different. Consequently, a number of patients' immune systems produce antibodies against it, neutralising its actions and resulting in inflammatory responses at injection sites. Added to these adverse effects of bovine and porcine insulin, were fears of long term complications ensuing from the regular injection of a foreign substance, (3) as well as a projected decline in the production of animal derived insulin. (4) These factors led researchers to consider synthesising Humulin by inserting the insulin gene into a suitable vector, the E. coli bacterial cell, to produce an insulin that is chemically identical to its naturally produced counterpart. This has been achieved using Recombinant DNA technology. This method (see fig. 2) is a more reliable and sustainable (5) method than extracting and purifying the abattoir by-product. An overview of the recombination process. Source: Novo -Nordisk promotional brochure,pg 6. Understanding the genetics involved. The structure of insulin. Chemically, insulin is a sm Continue reading >>

Dna Code For Insulin

Dna Code For Insulin

Introduction: Below are two partial sequences of DNA bases (shown for only one strand of DNA) Sequence 1 is from a human and sequence 2 is from a cow. In both humans and cows, this sequence is part of a set of instructions for controlling the production of a protein. In this case, the sequence contains the gene to make the protein insulin. Insulin is necessary for the uptake of sugar from the blood. Without insulin, a person cannot use digest sugars the same way others can, and they have a disease called diabetes. Materials: paper, pencil, codon table Procedure: Using the DNA sequence given in table 1, make a complimentary RNA strand for the human. Write the RNA directly below the DNA strand (remember to substitute U’s for T’s in RNA). Repeat step 1 for the cow. Write the RNA directly below the DNA strand in table 2. Use the codon table in your book to determine what amino acids are assembled to make the insulin protein in both the cow and the human. Write your amino acid chain directly below the RNA sequence. Table 1 Sequence 1 Human DNA C C A T A G C A C G T T A C A A C G T G A A G G T A A RNA Amino Acids Table 2 Sequence 1 Cow DNA C C G T A G C A T G T T A C A A C G C G A A G G C A C RNA Amino Acids Analysis: 1. The DNA sequence is different for the cow and the human, but the amino acid chain produced by the sequence is almost the same. How can this happen? 2. Diabetes is a disease characterized by the inability to break down sugars. Often a person with diabetes has a defective DNA sequence that codes for the making of the insulin protein. Suppose a person has a mutation in their DNA, and the first triplet for the gene coding for insulin is C C C (instead of C C A). Determine what amino acid the new DNA triplet codes for. Will this person be diabetic? 3. What if Continue reading >>

Insulin Synthesis And Secretion

Insulin Synthesis And Secretion

Insulin is a small protein, with a molecular weight of about 6000 Daltons. It is composed of two chains held together by disulfide bonds. The figure to the right shows a molecular model of bovine insulin, with the A chain colored blue and the larger B chain green. You can get a better appreciation for the structure of insulin by manipulating such a model yourself. The amino acid sequence is highly conserved among vertebrates, and insulin from one mammal almost certainly is biologically active in another. Even today, many diabetic patients are treated with insulin extracted from pig pancreas. Biosynthesis of Insulin Insulin is synthesized in significant quantities only in beta cells in the pancreas. The insulin mRNA is translated as a single chain precursor called preproinsulin, and removal of its signal peptide during insertion into the endoplasmic reticulum generates proinsulin. Proinsulin consists of three domains: an amino-terminal B chain, a carboxy-terminal A chain and a connecting peptide in the middle known as the C peptide. Within the endoplasmic reticulum, proinsulin is exposed to several specific endopeptidases which excise the C peptide, thereby generating the mature form of insulin. Insulin and free C peptide are packaged in the Golgi into secretory granules which accumulate in the cytoplasm. When the beta cell is appropriately stimulated, insulin is secreted from the cell by exocytosis and diffuses into islet capillary blood. C peptide is also secreted into blood, but has no known biological activity. Control of Insulin Secretion Insulin is secreted in primarily in response to elevated blood concentrations of glucose. This makes sense because insulin is "in charge" of facilitating glucose entry into cells. Some neural stimuli (e.g. sight and taste of food) Continue reading >>

Structural Biochemistry/protein Function/insulin

Structural Biochemistry/protein Function/insulin

Insulin is a hormone secreted by the pancreas that regulates glucose levels in the blood. Without insulin, cells cannot use the energy from glucose to carry out functions within the body. Insulin was first discovered in 1921 by Frederick Grant Banting and Charles Best from extracted substances from the pancreas of dogs in their laboratory. The material was then used to keep diabetic dogs alive, and then used in 1922 on a 14 year old diabetic boy. The FDA approved insulin in 1939. In 1966 insulin was synthesized by Michael Katsoyannis in his laboratory, which marked the first complete hormone to be successfully synthesized. Synthetic insulin is used as a drug to treat diabetes, and the current forms on the market include insulin from bovine and porcine pancreases, but the most widely used is a form made from recombinant human insulin. Insulin is made in the pancreas by beta cells. After the body takes in food, these beta cells release insulin, which enables cells in the liver, muscles and fat tissues to take up glucose and either store it as glycogen or allow blood to transfer it to organs in the body for use as an energy source. This process stops the use of fat as a source of energy. When glucose levels are elevated in the blood, insulin is produced at higher rates by the pancreas in order to maintain normal sugar concentrations in the blood. Without insulin, the body cannot process glucose effectively and glucose begins to build up in the blood stream instead of being transported to different cells . In contrast with elevated levels of glucose in the blood, when there is a deficit of glucose available to the body, alpha cells in the pancreas release glucagon, a hormone that causes the liver to convert stored glycogen into usable glucose which is then released into the Continue reading >>

Mutations In The Insulin Gene

Mutations In The Insulin Gene

Insulin plays a key role in the regulation of glucose homeostasis with diabetes resulting from insulin deficiency, whether complete deficiency as in type 1 diabetes or relative deficiency as in type 2 diabetes. Insulin, which is secreted from the pancreatic beta cells in a tightly regulated manner to maintain plasma glucose within a narrow range, is synthesized as the prohormone, preproinsulin. Post-translational proteolytic processing generates the mature two-chain insulin molecule. Mutations in the insulin gene cause disorders of glucose homeostasis through effects of the mutant insulin on beta cell function, insulin receptor affinity, or processing of proinsulin to insulin. The effects of the mutations on glucose homeostasis are variable with associated phenotypes ranging from permanent neonatal diabetes with complete insulin deficiency to near-normal glucose homeostasis. Maturity-onset diabetes of the young (MODY) and type 1b diabetes mellitus are other clinical manifestations of heterozygous insulin gene mutations. Insulin biosynthesis Insulin is the major biosynthetic and secretory product of the beta cell accounting for 50% or more of total protein synthesis when maximally stimulated corresponding to 1.3 x 106 molecules of insulin per minute [1]. The initial product of translation of human insulin mRNA is the single chain prohormone preproinsulin. The signal peptide of preproinsulin interacts with the signal recognition particle in the beta cell cytosol which targets proinsulin to the endoplasmic reticulum (ER). The signal peptide is rapidly cleaved and degraded Figure 1: (Click to enlarge)Diagrammatic representation of the amino acid sequence of human preproinsulin (signal peptide–green, B-chain–red, C-peptide–orange, A-chain–dark blue) indicating sites Continue reading >>

Sequence Of Human Insulin Gene

Sequence Of Human Insulin Gene

Abstract The human insulin gene contains two intervening sequences, one is within the region transcribed into the 5'-untranslated segment of the mRNA and the other interrupts the C-peptide encoding region. A comparison of the human with the rat insulin genes indicates potential regulatory regions in the DNA segment preceding the gene and suggests that the ancestral form of the insulin gene had two intervening sequences. Discover the world's research 14+ million members 100+ million publications 700k+ research projects Join for free Continue reading >>

Omim Entry - * 176730 - Insulin; Ins

Omim Entry - * 176730 - Insulin; Ins

Insulin, synthesized by the beta cells of the islets of Langerhans, consists of 2 dissimilar polypeptide chains, A and B, which are linked by 2 disulfide bonds. However, unlike many other proteins, e.g., hemoglobin, made up of structurally distinct subunits, insulin is under the control of a single genetic locus; chains A and B are derived from a 1-chain precursor, proinsulin, which was discovered by Steiner and Oyer (1967). Proinsulin is converted to insulin by the enzymatic removal of a segment that connects the amino end of the A chain to the carboxyl end of the B chain. This segment is called the C (for 'connecting') peptide. The human insulin gene contains 3 exons; exon 2 encodes the signal peptide, the B chain, and part of the C-peptide, while exon 3 encodes the remainder of the C-peptide and the A chain (Steiner and Oyer, 1967). The rat, mouse, and at least 3 fish species have 2 insulin genes (Lomedico et al., 1979). The single human insulin gene corresponds to rat gene II; each has 2 introns at corresponding positions. Deltour et al. (1993) showed that in the mouse embryo the 2 proinsulin genes are regulated independently, at least in part. The existence of a single insulin gene in man is supported by the findings in patients with mutations. The greatest variation among species is in the C-peptide. Receptor binding parts have been highly conserved. Some of these sites are involved with insulin-like activity, some with growth-factor activity, and some with both. INS-IGF2 Spliced Read-Through Transcripts By EST database analysis and RT-PCR, Monk et al. (2006) identified 2 read-through transcripts, which they called the INSIGF long and short isoforms, that contain exons from both the INS gene and the downstream IGF2 gene (147470). The INSIGF short isoform contains Continue reading >>

Overview: Dna Cloning

Overview: Dna Cloning

DNA cloning is a molecular biology technique that makes many identical copies of a piece of DNA, such as a gene. In a typical cloning experiment, a target gene is inserted into a circular piece of DNA called a plasmid. The plasmid is introduced into bacteria via process called transformation, and bacteria carrying the plasmid are selected using antibiotics. Bacteria with the correct plasmid are used to make more plasmid DNA or, in some cases, induced to express the gene and make protein. When you hear the word “cloning,” you may think of the cloning of whole organisms, such as Dolly the sheep. However, all it means to clone something is to make a genetically exact copy of it. In a molecular biology lab, what’s most often cloned is a gene or other small piece of DNA. If your friend the molecular biologist say that her “cloning” isn’t working, she's almost certainly talking about copying bits of DNA, not making the next Dolly! DNA cloning is the process of making multiple, identical copies of a particular piece of DNA. In a typical DNA cloning procedure, the gene or other DNA fragment of interest (perhaps a gene for a medically important human protein) is first inserted into a circular piece of DNA called a plasmid. The insertion is done using enzymes that “cut and paste” DNA, and it produces a molecule of recombinant DNA, or DNA assembled out of fragments from multiple sources. Diagram showing the construction of a recombinant DNA molecule. A circular piece of plasmid DNA has overhangs on its ends that match those of a gene fragment. The plasmid and gene fragment are joined together to produce a gene-containing plasmid. This gene-containing plasmid is an example of recombinant DNA, or a DNA molecule assembled from DNA from multiple sources. Next, the reco Continue reading >>

Cloning Insulin

Cloning Insulin

In 1978, Genentech scientist Dennis Kleid toured a factory in Indiana where insulin was being made from pigs and cattle. “There was a line of train cars filled with frozen pancreases,” he says. At the time, it took 8,000 pounds of pancreas glands from 23,500 animals to make one pound of insulin. Diabetics lack this hormone, which regulates the amount of glucose in the blood. The manufacturer, Eli Lilly, needed 56 million animals per year to meet the increasing U.S. demand for the drug. They had to find a new insulin alternative, fast. Genentech had the expertise to make synthetic human insulin—in laboratories, from bacteria, using their recently-proven recombinant DNA technology. But could they make enough of the miniscule insulin molecules to replace these trainloads of pancreases and provide an alternative option for people living with diabetes? The scientists would have to coax the bacteria to produce insulin from the synthetic DNA at high enough concentrations to make an economically viable product. This meant that each bacteria needed to churn out so much of the protein per cell that if they could do it, they’d look like stuffed olives under a microscope. If not, Genentech’s work would have ended as a scientific curiosity, with no new option for diabetics. I don’t want to hear that word, impossible...tell me what you need to get it done. Kleid didn’t think they could get that kind of yield. He told Genentech founder, Bob Swanson, flat-out that it couldn’t be done. But Swanson refused to accept it. “I don’t want to hear that word, impossible,” he told Kleid. “Tell me what you need to get it done.” The high-stakes, high-pressure race to create synthetic insulin had started over a year earlier. Eli Lilly, the main U.S. producer of insulin, ha Continue reading >>

The Insulin Receptor Cellular Ires Confers Resistance To Eif4a Inhibition

The Insulin Receptor Cellular Ires Confers Resistance To Eif4a Inhibition

Under conditions of stress, such as limited growth factor signaling, translation is inhibited by the action of 4E-BP and PDCD4. These proteins, through inhibition of eIF4E and eIF4A, respectively, impair cap-dependent translation. Under stress conditions FOXO transcription factors activate 4E-BP expression amplifying the repression. Here we show that Drosophila FOXO binds the PDCD4 promoter and stimulates the transcription of PDCD4 in response to stress. We have shown previously that the 5′ UTR of the Drosophila insulin-like receptor (dINR) supports cap-independent translation that is resistant to 4E-BP. Using hippuristanol, an eIF4A inhibitor, we find that translation of dINR UTR containing transcripts are also resistant to eIF4A inhibition. In addition, the murine insulin receptor and insulin-like growth factor receptor 5′ UTRs support cap-independent translation and have a similar resistance to hippuristanol. This resistance to inhibition of eIF4E and eIF4A indicates a conserved strategy to allow translation of growth factor receptors under stress conditions. Protein synthesis in eukaryotes occurs in two stages: transcription of DNA into messenger RNA (mRNA) in the nucleus, and then translation of that mRNA into a protein by ribosomes in the cytoplasm. These processes are regulated by a complex network of signaling pathways that enables cells to tailor protein synthesis to match current conditions. This involves regulating the expression of the genes that code for these proteins. When cells experience stressful events, such as a shortage of oxygen or nutrients, they reduce the synthesis of most proteins. This response is regulated, in part, by a signaling pathway known as the insulin and insulin-like receptor pathway. In particular, stressful events inhibit a pro Continue reading >>

Answers To Text Questions

Answers To Text Questions

(See related pages) Inquiry Questions None for this chapter. Self Test 1). The bases of RNA are the same as those of DNA with the exception that RNA contains a). cysteine instead of cytosine. b). uracil instead of thymine. c). cytosine instead of guanine. d). uracil instead of adenine. Answer: b 2). Which one of the following is not a type of RNA? a). nRNA (nuclear RNA) b). mRNA (messenger RNA) c). rRNA (ribosomal RNA) d). tRNA (transfer RNA) Answer: a 3). Each amino acid in a protein is specified by a). several genes. b). a promoter. c). an mRNA molecule. d). a codon. Answer: d 4). The three-nucleotide codon system can be arranged into ______________ combinations. a). 16 b). 20 c). 64 d). 128 Answer: c 5). The TATA box in eukaryotes is a a). core promoter. b). – 35 sequence. c). – 10 sequence. d). 5' cap. Answer: a 6). The site where RNA polymerase attaches to the DNA molecule to start the formation of RNA is called a(n) a). promoter. b). exon. c). intron. d). GC hairpin. Answer: a 7). When mRNA leaves the cell's nucleus, it next becomes associated with a). proteins. b). a ribosome. c). tRNA. d). RNA polymerase. Answer: b 8). If an mRNA codon reads UAC, its complementary anticodon will be a). TUC. b). ATG. c). AUG. d). CAG. Answer: c 9). The nucleotide sequences on DNA that actually have information encoding a sequence of amino acids are a). introns. b). exons. c). UAA. d). UGA. Answer: b 10). Which of the following statements is correct about prokaryotic gene expression? a). Prokaryotic mRNAs must have introns spliced out. b). Prokaryotic mRNAs are often translated before transcription is complete. c). Prokaryotic mRNAs contain the transcript of only one gene. d). All of these statements are correct. Answer: b Test Your Visual Understanding 1). Match the correct l Continue reading >>

Ins Insulin [ Homo Sapiens (human) ]

Ins Insulin [ Homo Sapiens (human) ]

Data suggest early peaks in glucagon-like peptide-1 and glucagon secretion/blood level together trigger exaggerated insulinotropic response (high insulin secretion/level) to eating and consequent hypoglycaemia in patients with postprandial hypoglycaemia as a postoperative complication following Roux-en-Y gastric bypass for obesity complicated by type 2 diabetes; this retrospective cohort study was conducted in London. Studies on the susceptibility to aggregation of truncated analogs of insulin amyloidogenic core show three groups of peptides. Truncation of A13-A419 fragment shows that fibrous structures are formed by all peptides bearing (13)H-LeuTyr-OH(14). Propensity to aggregation was found for (16)H-TyrLeu-OH(17) B12-B17 fragment. Insulin secretion by pancreatic beta-cells increases after adrenalectomy for aldosterone-producing adenomas; adrenalectomy in these patients prevents primary aldosteronism; such data suggest that aldosterone excess inhibits insulin secretion by pancreatic beta-cells. This retrospective study was conducted in Japan. Continue reading >>

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