What is the function of GAPDH enzyme?
Glyceraldehyde 3-phosphate dehydrogenase (abbreviated GAPDH) (EC 1.2.1.12) is an enzyme of about 37kDa that catalyzes the sixth step of glycolysis and thus serves to break down glucose for energy and carbon molecules.
What is the structure of GAPDH?
In sperm, a testis-specific isoenzyme GAPDHS is expressed. Under normal cellular conditions, cytoplasmic GAPDH exists primarily as a tetramer. This form is composed of four identical 37- kDa subunits containing a single catalytic thiol group each and critical to the enzyme's catalytic function.
What is the role of GAPDH in autophagy?
Data revealed that GAPDH is a phosphorylation substrate for AMPK and its interaction with Sirt1 in the nucleus. The phosphorylation and the nuclear translocation of GAPDH mediate rapid Sirt1 activation and autophagy initiation under glucose deprivation.
What is the function of GAPDH in MEK?
GAPDH is a moonlighting protein that functions as a glycolytic enzyme as well as a uracil DNA glycosylase. Results indicate that CIB1 is uniquely positioned to regulate PI3K/AKT and MEK/ERK signaling and that simultaneous disruption of these pathways synergistically induces a nuclear GAPDH-dependent cell death.
Where is GAPDH used?
Western blottingFor this reason, GAPDH is widely used as a loading control for protein normalization in Western blotting. It is also useful for cell visualization in microscopy assays and can be used to investigate cell metabolism and functional activity.
What type of control is GAPDH?
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), initially identified as a glycolytic enzyme and considered as a housekeeping gene, is widely used as an internal control in experiments on proteins, mRNA, and DNA.
Why GAPDH is a housekeeping gene?
GAPDH is a key regulatory enzyme, which catalyzes the oxidative phosphorylation of glyceraldehyde-3-phosphate during glycolysis. β-actin is a cytoskeletal protein involved in cell structure and motility. Based on these basic and ubiquitous cellular functions, GAPDH and β-actin are considered as housekeeping genes.
What is GAPDH used for in PCR?
GAPDH is frequently used as an endogenous control for quantitative RT-PCR analysis because its expression is consistent at different time points and various experimental manipulations [25].
Is GAPDH a good loading control?
GAPDH can work as a reliable loading control only in Rhesus monkeys model of myocardial ischemia. Total protein level is the best loading control for western blot in animal models of myocardial ischemic infarction.
Is GAPDH an antibody?
This GAPDH antibody can be used as a loading control antibody. GAPDH is a 146 kDa tetramer composed of four 30-40 kDa subunits. There is no cross-reaction with GAPDH from yeast.
What is the role of housekeeping genes?
Housekeeping genes are cellular maintenance genes which regulate basic and ubiquitous cellular functions. In many RT-qPCR reactions, these genes are used as internal control genes without proper validation.
What is the best housekeeping gene?
The top 3 most stable housekeeping genes were: UBC, SDHA and ARBP for all states. Following statistical analysis using the Mann-Whitney-U Test, only UBC and SDHA for the 24 hr ligated, 2 wk ligated and 2 wk ligated + 3 day de-ligated states showed no change from the unoperated control group (>0.05) (Figure 4).
What is a housekeeping gene used for?
The concept of housekeeping genes Housekeeping genes are genes that are required for the maintenance of basal cellular functions that are essential for the existence of a cell, regardless of its specific role in the tissue or organism.
Is GAPDH a primer?
Primers specific to the gene GAPDH, or glyceraldehyde 3-phosphate dehydrogenase, are often used in PCR-based experiments as a type of control. GAPDH is an enzyme involved in glycolysis and is widely expressed among many mammalian cell types.
Is GAPDH a protein?
GAPDH is a moonlighting protein that functions as a glycolytic enzyme as well as a uracil DNA glycosylase.
What are housekeeping proteins?
Housekeeping protein. (Science: molecular biology) Those sets of proteins involved in the basic functioning of a cell or the set of cells in an organism, for example enzymes involved in synthesis and processing of dna, rna, proteins or the major metabolic pathways. as opposed to luxury proteins.
How does GapDH work?
GAPDH acts as a reversible metabolic switch under oxidative stress. When cells are exposed to oxidants, they need excessive amounts of the antioxidant cofactor NADPH. In the cytosol, NADPH is reduced from NADP+ by several enzymes, three of them catalyze the first steps of the Pentose phosphate pathway. Oxidant-treatments cause an inactivation of GAPDH. This inactivation re-routes temporally the metabolic flux from glycolysis to the Pentose Phosphate Pathway, allowing the cell to generate more NADPH. Under stress conditions, NADPH is needed by some antioxidant-systems including glutaredoxin and thioredoxin as well as being essential for the recycling of gluthathione .
How is GAPDH regulated?
GAPDH activity in aerobic and anaerobic glycolysis can be regulated by a leaky channeling complex with L-lactate dehydrogenase that can form only at the limiting NAD (H) concentrations. Positive electric field dominate between the adjacent NAD (H) binding sites on GAPDH tetramers, and merge with the positive electric fields between NAD (H) binding sites on the adjacent subunits in LDH tetramers. The structures indicate that the NAD (H)-channeling within the transient GAPDH-LDH complex can be an extension of NAD (H)-channeling between the adjacent subunits in GAPDH tetramer.
What are the interactions of GapDH?
GAPDH has been implicated in several neurodegenerative diseases and disorders, largely through interactions with other proteins specific to that disease or disorder. These interactions may affect not only energy metabolism but also other GAPDH functions. For example, GAPDH interactions with beta-amyloid precursor protein (betaAPP) could interfere with its function regarding the cytoskeleton or membrane transport, while interactions with huntingtin could interfere with its function regarding apoptosis, nuclear tRNA transport, DNA replication, and DNA repair. In addition, nuclear translocation of GAPDH has been reported in Parkinson's disease (PD), and several anti-apoptotic PD drugs, such as rasagiline, function by preventing the nuclear translocation of GAPDH. It is proposed that hypometabolism may be one contributor to PD, but the exact mechanisms underlying GAPDH involvement in neurodegenerative disease remains to be clarified. The SNP rs3741916 in the 5' UTR of the GAPDH gene may be associated with late onset Alzheimer's disease.
What is the name of the intermediate that collapses to release 1,3-bisphosphoglycerate?
Finally, a molecule of inorganic phosphate attacks the thioester and forms a tetrahedral intermediate, which then collapses to release 1,3-bisphosphoglycerate, and the thiol group of the enzyme's cysteine residue.
Why is GapDH used in Western Blot?
Use as loading control. Because the GAPDH gene is often stably and constitutively expressed at high levels in most tissues and cells , it is considered a housekeeping gene. For this reason, GAPDH is commonly used by biological researchers as a loading control for western blot and as a control for qPCR.
What is the name of the enzyme that converts glyceraldehyde 3-phosphate to D
As its name indicates, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) catalyses the conversion of glyceraldehyde 3-phosphate to D - glycerate 1,3-bisphosphate.
What is the enzyme that breaks down glucose?
Glyceraldehyde 3-phosphate dehydrogenase (abbreviated GAPDH) ( EC 1.2.1.12) is an enzyme of about 37kDa that catalyzes the sixth step of glycolysis and thus serves to break down glucose for energy and carbon molecules.
What are the functions of GAPDH?
These include membrane fusion and cytoskeleton dynamics, as well as DNA repair and RNA export.
What is the enzyme that breaks down glucose?
Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is an enzyme involved in breaking down glucose to obtain energy. More specifically, in eukaryotes, this enzyme catalyzes the sixth step in glycolysis, converting glyceraldehyde 3-phosphate to D-glycerate 1,3-bisphosphate (1,3-BPG).
What is the reaction between aldehyde and acyl phosphate?
The reaction occurs in two coupled steps: first, aldehyde is converted to a carboxylic acid in the presence of NAD +, and secondly a molecule of organic phosphate is added to this to generate the acyl-phosphate end-product. The reaction starts between the aldehyde and one of the sulfhydryl groups in GAPDH to form a hemithioacetal.
Is GAPDH a housekeeping gene?
New roles for GAPDH. Once its function was believed to have been unveiled to the last detail, GAPDH was thrown in the “housekeeping gene” list and considered devoid of any significant research impact. However, recent studies have found that GAPDH is capable of multiple functions completely unrelated to its participation in glycolysis 3.
Does gapdh interact with huntingtin?
It has been tentatively suggested that GAPDH can interact with mutant huntingtin and β-amyloid peptides, respectively 9,10. Browse all GAPDH products.
What is the GAPDH gene?
coli, P. aeruginosa, and C. albicans. GAPDH gene over expression in resected tumor samples is an adverse prognostic factor in non small cell lung cancer.
What is the siah-1 protein?
siah-1 Protein is necessary for high glucose-induced glyceraldehyde-3-phosphate dehydrogenase nuclear accumulation and cell death in Muller. These results suggest that aggregate-prone mutations of GAPDH such as S284C-GAPDH may confer risk of oxidative stress-induced cell death.
Is GAPD a pseudogene?
The GAPD gene and its pseudogene may play a role in the development of late-onset Alzheimer disease. However, the effect, if any, is likely to be limited. identified glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as a new interacting partner of TPPP/p25 within the alpha-synuclein positive Lewy body.
3 Proteins
Has both glyceraldehyde-3-phosphate dehydrogenase and nitrosylase activities, thereby playing a role in glycolysis and nuclear functions, respectively (PMID: 3170585, PMID: 11724794 ).
11 Information Sources
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What is the role of GAPDH in DNA repair?
Role of Glyceraldehyde-3-Phosphate Dehydrogenase (GAPDH) in DNA Repair. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is widely known as a glycolytic enzyme. Nevertheless, various functions of GAPDH have been found that are unrelated to glycolysis.
What is the role of GapDH in apoptosis?
When in the nucleus, GAPDH participates in the initiation of apoptosis and transcription of genes involved in antiapoptotic pathways and cell proliferation and plays a role in the regulation of telomere length.
Does GapDH interact with DNA?
Several authors have shown that GAPDH displays the uracil-DNA glycosylase activity and interacts with some types of DNA damage s, such as apurinic/apyrimidinic sites, nucleotide analogs, and covalent DNA adducts with alkylating agents.
Is GAPDH a glycolytic enzyme?
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is widely known as a glycolytic enzyme. Nevertheless, various functions of GAPDH have been found that are unrelated to glycolysis. Some of these functions presume interaction of GAPDH with DNA, but the mechanism of its translocation to the nucleus is not fully understood.
What is the function of the glyceraldehyde-3-phosphate dehydrogenas
The product of this gene catalyzes an important energy-yielding step in carbohydrate metabolism, the reversible oxidative phosphory lation of glyceraldehyde-3-phosphate in the presence of inorganic phosphate and nicotinamide adenine dinucleotide (NAD). The encoded protein has additionally been identified to have uracil DNA glycosylase activity in the nucleus. Also, this protein contains a peptide that has antimicrobial activity against E. coli, P. aeruginosa, and C. albicans. Studies of a similar protein in mouse have assigned a variety of additional functions including nitrosylation of nuclear proteins, the regulation of mRNA stability, and acting as a transferrin receptor on the cell surface of macrophage. Many pseudogenes similar to this locus are present in the human genome. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2014]
What is the product of glyceraldehyde-3-phosphate?
The product of this gene catalyzes an important energy-yielding step in carbohydrate metabolism, the reversible oxidative phosphorylation of glyceraldehyde-3-phosphate in the presence of inorganic phosphate and nicotinamide adenine dinucleotide (NAD).
What is the moonlighting protein?
The encoded protein has been identified as a moonlighting protein based on its ability to perform mechanistically distinct functions. The product of this gene catalyzes an important energy-yielding step in carbohydrate metabolism, the reversible oxidative phosphorylation of glyceraldehyde... See more...
Overview
Glyceraldehyde 3-phosphate dehydrogenase (abbreviated GAPDH) (EC 1.2.1.12) is an enzyme of about 37kDa that catalyzes the sixth step of glycolysis and thus serves to break down glucose for energy and carbon molecules. In addition to this long established metabolic function, GAPDH has recently been implicated in several non-metabolic processes, including transcription activation, initiation of
Structure
Under normal cellular conditions, cytoplasmic GAPDH exists primarily as a tetramer. This form is composed of four identical 37-kDa subunits containing a single catalytic thiol group each and critical to the enzyme's catalytic function. Nuclear GAPDH has increased isoelectric point (pI) of pH 8.3–8.7. Of note, the cysteine residue C152 in the enzyme's active site is required for the induction of apoptosis by oxidative stress. Notably, post-translational modifications of cytoplasmic GAPDH …
Reaction
Compound C00118 at KEGG Pathway Database. Enzyme 1.2.1.12 at KEGG Pathway Database. Reaction R01063 at KEGG Pathway Database. Compound C00236 at KEGG Pathway Database.
The first reaction is the oxidation of glyceraldehyde 3-phosphate (G3P) at the position-1 (in the diagram it is shown as the 4th carbon from glycolysis), in which an aldehyde is converted into a carboxylic acid (ΔG°'=-50 kJ/mol (−12kcal/mol)) and NAD+ is simultaneously reduced endergoni…
Function
As its name indicates, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) catalyses the conversion of glyceraldehyde 3-phosphate to D-glycerate 1,3-bisphosphate. This is the 6th step in the glycolytic breakdown of glucose, an important pathway of energy and carbon molecule supply which takes place in the cytosol of eukaryotic cells. The conversion occurs in two coupled steps. The first is favourable and allows the second unfavourable step to occur.
Use as loading control
Because the GAPDH gene is often stably and constitutively expressed at high levels in most tissues and cells, it is considered a housekeeping gene. For this reason, GAPDH is commonly used by biological researchers as a loading control for western blot and as a control for qPCR. However, researchers have reported different regulation of GAPDH under specific conditions. For example, the transcription factor MZF-1 has been shown to regulate the GAPDH gene. Hypoxia also strongl…
Cellular distribution
All steps of glycolysis take place in the cytosol and so does the reaction catalysed by GAPDH. In red blood cells, GAPDH and several other glycolytic enzymes assemble in complexes on the inside of the cell membrane. The process appears to be regulated by phosphorylation and oxygenation. Bringing several glycolytic enzymes close to each other is expected to greatly increase the overall speed of glucose breakdown. Recent studies have also revealed that GAPD…
Clinical significance
GAPDH is overexpressed in multiple human cancers, such as cutaneous melanoma, and its expression is positively correlated with tumor progression. Its glycolytic and antiapoptotic functions contribute to proliferation and protection of tumor cells, promoting tumorigenesis. Notably, GAPDH protects against telomere shortening induced by chemotherapeutic drugs that stimulate the sphingolipid ceramide. Meanwhile, conditions like oxidative stress impair GAPDH fu…
Interactions
GAPDH participates in a number of biological functions through its protein–protein interactions with:
• tubulin to facilitate microtubule bundling;
• actin to facilitate actin polymerization;
• VDAC1 to induce mitochondrial membrane permeabilization (MMP) and apoptosis;