PCR GAPDH Genes Parsley
PCR Analysis of GAPDH Genes in Parsley
The purpose of this review is to consider the structure and the function of the protein glyceraldehyde-3-phosphate dehydrogenase (GAPDH, EC 1.2.1.12) in Petroselinum crispum and Coriandrum sativum cells. For over three decades, GAPDH was studied for its pivotal role in glycolysis. As an abundant cell protein, it proved useful as a model for investigations examining basic mechanisms of enzyme action as well as the relationship between amino acid sequence and protein structure. Further, with the advent of molecular technology, GAPDH, as a putative ‘house-keeping’ gene, provided a model with which to use new methods for gene analysis to advance our understanding of the mechanisms through which cells organize and express their genetic information.
As with many things in life, what is thought to be simple and relatively straight-forward turns out to be quite complex and elaborate. In this regard, a number of studies, accelerating in the last decade, have indicated that GAPDH is not an uncomplicated, simple glycolytic protein. Instead, independent laboratories identified diverse biological properties of the mammalian GAPDH protein. These included roles for GAPDH in membrane transport and in membrane fusion, microtubule assembly, nuclear RNA export, protein phosphotransferase/kinase reactions, the translational control of gene expression, DNA replication and DNA repair. Each activity appears to be distinct from its glycolytic function (Sirover, 1999).
The gene that codes for the enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is of the same name. GAPDH is a crucial enzyme in glycolysis. The gene is known as a housekeeping gene — a gene that is expressed constitutively and is necessary for cells to survive. Since GAPDH is abundant in cells and can be purified for study, much is known about the protein structure and function. GAPDH consists of four subunits (hence a tetramer) held together through non-covalent attachments. All four subunits may be identical (designated as A4, a homodimer) or they may consist of pairs of slightly different subunits (designated A2B2, a heterodimer). In both cases, each subunit has an active site and can bind one molecule of NAD+ cofactor.
GAPDH protein has two major domains, the amino terminal has an NAD+ binding domain and the carboxy terminal has glyceraldehyde 3′ phosphate dehydrogenase activity. GAPDH protein domain structure. The active cysteine is in the catalytic site. In addition, recent research has found that GAPDH plays many other roles outside of glycolysis. For example, the human GAPDH gene is overexpressed (i.e., expressed at levels much higher than normal) in 21 different classes of cancer (Altenburg and Greulich, 2004). GAPDH has been shown to play roles in membrane fusion, endocytosis, microtubule bundling, and DNA repair. GAPDH is also involved in viral pathogenesis, regulation of apoptosis (programmed cell death), and human neuronal diseases including Alzheimer’s and Huntington’s disease (reviewed in Sirover 1999).
GAPDH catalyzes the sixth reaction of glycolysis, the pathway by which glucose is converted into pyruvate in a series of ten enzymatic reactions. In mammals, most dietary polysaccharides are broken down to glucose in the bloodstream. In plants, glucose is synthesized from carbon dioxide in the Calvin cycle of photosynthesis.
Glycolysis has a number of useable products:
• The production of ATP and NADH during glycolysis, providing energy for the cells
• Pyruvate, the end product of glycolysis, feeds into the citric acid cycle, producing more energy for the cells
• Many of the intermediate compounds of glycolysis are precursors for the formation of other biological molecules. For example, glucose-6-phosphate is a precursor for the synthesis of ADP, NAD+, and coenzyme Q, and phosphoenolpyruvate is a precursor for the synthesis of the amino acids, tyrosine, phenylalanine, and tryptophan.
The reaction catalyzed by GAPDH is:
Glyceraldehyde-3-phosphate + NAD+ + PiAE1,3-bisphosphoglycerate + NADH + H+
GAPDH oxidizes glyceraldehyde-3-phosphate (GAP) by removing a hydrogen ion (H+) and transferring it to the acceptor molecule, NAD+ (NAD+ + H+AENADH). In addition, GAPDH adds a second phosphate group to GAP. This reaction is catalyzed by a cysteine in the active site of the GAPDH protein.
When the source of carbohydrate for glycolysis is a sugar, glycolysis will occur in the cytosol, as it does in animal cells. When the carbohydrate source is starch however, glycolysis can occur in plastids (a group of organelles that includes chloroplasts).
GAPDH Genes in Plants and their Origins
Plants such as Petroselinum Crispum and Coraindrum sativum contain three forms of GAPDH: a cytosolic form which participates in glycolysis and two chloroplast forms which participates in photosynthesis. These three forms are encoded by distinct genes. In plants there are two metabolic pathways for carbohydrates: the Calvin Cycle in chloroplasts and glycolysis in the cytosol. The pathways share some enzymatic reactions (including the reaction catalyzed by GAPDH), but the enzymes in the two pathways are not identical even though they catalyze the same reactions in both pathways. The enzymes in the two pathways are isozymes or isoenzymes, homologous enzymes that catalyze the same reaction but differ in amino acid sequence. A separate gene encodes each isoenzyme, and all of the genes are nuclear (reviewed in Plaxton 1996).
For example, the enzyme hexokinase phosphorylates glucose both in the chloroplast and in the cytosol, but two separate genes in the plant cell nucleus encode cytosolic hexokinase and chloroplastic hexokinase. Isozymes are very common in plants and animals, and typically result from a gene duplication event that occurred millions of years ago. Sometimes the gene duplication event occurred within the nucleus itself. There are also genes located on chromosomal DNA that appear to have been transferred there from mitochondrial or plastid DNA. One of the observations about mitochondria and plastids that led to the endosymbiotic theory of evolution (that these organelles exist due to an ancient symbiotic event between prokaryotes and eukaryotes) is the fact that they contain DNA that is similar to bacterial DNA.
It was more than one billion years ago that photosynthetic cyanobacteria were engulfed by eukaryotic cells, becoming the antecedents of modern plastids. The resulting sub-cellular organelles, plastids, have taken over many reactions for their host cells, including photosynthesis, carbohydrate metabolism, amino acid synthesis, lipid production, photorespiration, and nitrogen/sulfur reduction. At the same time, plastids still have their own DNA, as well as the machinery for replication, transcription, and translation. However, plastids retain only a fraction of the genome that their ancestors had. The plastid genome encodes between 120 — 135 genes (Lopez-Juez 2007), whereas the closest living relative to the plastid ancestor, cyanobacteria of the genus Nostoc (Martin et al., 2002), have between 3,000 — 7,000 genes.
Most genes originally found in the symbiotic cyanobacteria are now found in the plant cell nucleus. Martin et al. (2002) report that about 18% of the protein-coding genes in Arabidopsis thaliana derive from cyanobacteria. However, the gene transfer was not one way. Genes that pre-existed in the nuclear genome have also been transferred to the plastid genome, but gene expression in the plastid is under nuclear control and most plastid proteins are encoded by nuclear DNA. All GAPDH isozymes found in eukaryotes are nuclear-encoded and are believed to have originated in cyanobacteria (Martin et al., 2002). The duplication of GAPDH genes that gave rise to the chloroplastid form is believed to have occurred during the period when land plants first emerged (Teich et al., 2007), and subsequent gene duplications resulted in the multiple forms now present in modern plants.
Analyzing the GAPDH gene of organisms can reveal differences between them that are important for plant evolution and survival. Plastids, the light-harvesting organelles of plants and algae, are the descendants of cyanobacterial endosymbionts that became permanent fixtures inside nonphotosynthetic eukaryotic host cells. The structural, functional and molecular diversity of plastids in the context of current views on the evolutionary relationships among the eukaryotic hosts in which they reside can be revealed through differences in GAPDH. Green algae, land plants, red algae and glaucophyte algae harbor double-membrane-bound plastids whose ancestry is generally believed to trace directly to the original cyanobacterial endosymbiont, like GAPDH. In contrast, the plastids of many other algae, such as dinoflagellates, diatoms and euglenids, are usually bound by more than two membranes, suggesting that these were acquired indirectly via endosymbiotic mergers between nonphotosynthetic eukaryotic hosts and eukaryotic algal endosymbionts. An increasing amount of PCR analysis of GAPDH genes from diverse photosynthetic taxa has made it possible to test specific hypotheses about the evolution of photosynthesis in eukaryotes and, consequently, improve our understanding of the genomic and biochemical diversity of modern-day eukaryotic phototrophs (Kim and Archibald, 2009).
Works Cited
Kim, E. And Archibald, J. (2009) Diversity and Evolution of Plastids and Their Genomes. Plant Cell Monograph. 1-39.
Lopez-Juez, E. 2007. Plastid biogenesis, between light and shadows. J. Exper. Bot. 58: 11 — 26.
Martin, W., Rujan, T., Richly, E., Hansen, A., Cornelsen, S., Lins, T., Leister, D., Stoebe, B., Hasegawa, M, & Penny, D. 2002. Evolutionary analysis of Arabidopsis, cyanobacterial, and chloroplast genomes reveals plastic phylogeny and thousands of cyanobacterial genes in the nucleus. PNAS 99: 12246 — 12251.
Plaxton, W.C. 1996. The organization and regulation of plant glycolysis. Annu. Rev. PlantPhysiol. Plant Mol. Biol. 47: 185 — 214.
Sirover, M.A. 1999. New insights into an old protein: the functional diversity of mammalian glyceraldehyde-3-phosphate dehydrogenase. Bioch. Biophys. Acta 1432: 159 — 184.
Teich, R., Grauvogel, C., & Petersen, J. 2007. Intron distribution in Plantae: 500 million years of stasis during land plant evolution. Gene 394: 96 — 104.
Are you busy and do not have time to handle your assignment? Are you scared that your paper will not make the grade? Do you have responsibilities that may hinder you from turning in your assignment on time? Are you tired and can barely handle your assignment? Are your grades inconsistent?
Whichever your reason is, it is valid! You can get professional academic help from our service at affordable rates. We have a team of professional academic writers who can handle all your assignments.
Students barely have time to read. We got you! Have your literature essay or book review written without having the hassle of reading the book. You can get your literature paper custom-written for you by our literature specialists.
Do you struggle with finance? No need to torture yourself if finance is not your cup of tea. You can order your finance paper from our academic writing service and get 100% original work from competent finance experts.
Computer science is a tough subject. Fortunately, our computer science experts are up to the match. No need to stress and have sleepless nights. Our academic writers will tackle all your computer science assignments and deliver them on time. Let us handle all your python, java, ruby, JavaScript, php , C+ assignments!
While psychology may be an interesting subject, you may lack sufficient time to handle your assignments. Don’t despair; by using our academic writing service, you can be assured of perfect grades. Moreover, your grades will be consistent.
Engineering is quite a demanding subject. Students face a lot of pressure and barely have enough time to do what they love to do. Our academic writing service got you covered! Our engineering specialists follow the paper instructions and ensure timely delivery of the paper.
In the nursing course, you may have difficulties with literature reviews, annotated bibliographies, critical essays, and other assignments. Our nursing assignment writers will offer you professional nursing paper help at low prices.
Truth be told, sociology papers can be quite exhausting. Our academic writing service relieves you of fatigue, pressure, and stress. You can relax and have peace of mind as our academic writers handle your sociology assignment.
We take pride in having some of the best business writers in the industry. Our business writers have a lot of experience in the field. They are reliable, and you can be assured of a high-grade paper. They are able to handle business papers of any subject, length, deadline, and difficulty!
We boast of having some of the most experienced statistics experts in the industry. Our statistics experts have diverse skills, expertise, and knowledge to handle any kind of assignment. They have access to all kinds of software to get your assignment done.
Writing a law essay may prove to be an insurmountable obstacle, especially when you need to know the peculiarities of the legislative framework. Take advantage of our top-notch law specialists and get superb grades and 100% satisfaction.
We have highlighted some of the most popular subjects we handle above. Those are just a tip of the iceberg. We deal in all academic disciplines since our writers are as diverse. They have been drawn from across all disciplines, and orders are assigned to those writers believed to be the best in the field. In a nutshell, there is no task we cannot handle; all you need to do is place your order with us. As long as your instructions are clear, just trust we shall deliver irrespective of the discipline.
Our essay writers are graduates with bachelor's, masters, Ph.D., and doctorate degrees in various subjects. The minimum requirement to be an essay writer with our essay writing service is to have a college degree. All our academic writers have a minimum of two years of academic writing. We have a stringent recruitment process to ensure that we get only the most competent essay writers in the industry. We also ensure that the writers are handsomely compensated for their value. The majority of our writers are native English speakers. As such, the fluency of language and grammar is impeccable.
There is a very low likelihood that you won’t like the paper.
Not at all. All papers are written from scratch. There is no way your tutor or instructor will realize that you did not write the paper yourself. In fact, we recommend using our assignment help services for consistent results.
We check all papers for plagiarism before we submit them. We use powerful plagiarism checking software such as SafeAssign, LopesWrite, and Turnitin. We also upload the plagiarism report so that you can review it. We understand that plagiarism is academic suicide. We would not take the risk of submitting plagiarized work and jeopardize your academic journey. Furthermore, we do not sell or use prewritten papers, and each paper is written from scratch.
You determine when you get the paper by setting the deadline when placing the order. All papers are delivered within the deadline. We are well aware that we operate in a time-sensitive industry. As such, we have laid out strategies to ensure that the client receives the paper on time and they never miss the deadline. We understand that papers that are submitted late have some points deducted. We do not want you to miss any points due to late submission. We work on beating deadlines by huge margins in order to ensure that you have ample time to review the paper before you submit it.
We have a privacy and confidentiality policy that guides our work. We NEVER share any customer information with third parties. Noone will ever know that you used our assignment help services. It’s only between you and us. We are bound by our policies to protect the customer’s identity and information. All your information, such as your names, phone number, email, order information, and so on, are protected. We have robust security systems that ensure that your data is protected. Hacking our systems is close to impossible, and it has never happened.
You fill all the paper instructions in the order form. Make sure you include all the helpful materials so that our academic writers can deliver the perfect paper. It will also help to eliminate unnecessary revisions.
Proceed to pay for the paper so that it can be assigned to one of our expert academic writers. The paper subject is matched with the writer’s area of specialization.
You communicate with the writer and know about the progress of the paper. The client can ask the writer for drafts of the paper. The client can upload extra material and include additional instructions from the lecturer. Receive a paper.
The paper is sent to your email and uploaded to your personal account. You also get a plagiarism report attached to your paper.
GET A PERFECT SCORE!!! 
Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.
You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.
Read moreEach paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.
Read moreThanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.
Read moreYour email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.
Read moreBy sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.
Read more