DNA Repair
DNA Repair Antibodies | Non-homologous End-joining| Nucleotide Excision Repair | Homologous Recombination | Direct Reversal of DNA Method
DNA repair refers to a collection of processes by which cells identify and correct damaged DNA. In human cells, normal metabolic activities and environmental factors cause DNA damage. Lesions resulting from DNA damage cause structural changes that can prevent gene transcription and induce harmful mutations in the cells genome. The rate of DNA repair is dependent of many factors, including cell type, cell age and the extracellular environment. The DNA repair ability of a cell is vital to the integrity of its genome, and thus to its normal function. A cell that has accumulated a large amount of DNA damage or that can no longer effectively repair damage can enter one of three stages: senescence, apoptosis or unregulated cell division, which can lead to the formation of a malignant tumor.
Antibodies Used in DNA Repair
Antibodies are a common tool in DNA repair, with hundreds of subgroups that mark specific proteins. For example, the p53 antibody family includes the 53BP1 antibody, which acts on an associated protein. However, it is still part of the p53 pathway.
We, at Novus Biologicals, have a vast catalog of antibodies, allowing highly specific assays of a full range of DNA-related proteins. Our ATM, FANCD2, RAD51, p53, TERT and PARP antibody ranges are routinely used in laboratories across the world.
The p53 antibody family
p53 is a tumor-suppressing protein which plays an important role in the development of cancer cells. It is sited at the junction of a network of signalling pathways. Depending on its interaction with other proteins, it can either prevent or initiate programmed cell death. Its disruption is implicated in a wide range of cancers.
p53 antibody nomenclature relates to the action of that antibody in the p53 pathway. For instance, the rabbit polyclonal anti-p53 antibody (catalog number: NB200-171) acts upon the p53 protein itself, whereas the rabbit polyclonal anti-53BP1 antibody (catalog number: NB100-904) maps to a specific region of p53 binding protein 1.
The 53BP1 Antibody
The tumor binding protein 53BP1 plays a critical role in tumor suppression in the p53 pathway. It is also thought to be involved with DNA repair.
Different 53BP1 antibody types are specific to particular residues on the 53BP1 protein. For example, rabbit polyclonal anti-53BP1 antibody (catalog number: NB100-305) maps to a region between amino acid residues 1925 and 1972. A different rabbit polyclonal anti-53BP1 antibody (catalog number: NB100-304) maps to a region between amino acid residues 350 and 400.
The FANCD2 Antibody
The FANCD2 antibody interacts with FANCD proteins, which are implicated in Fanconi anaemia - a genetic disease. FANCD is essential for cellular repair after cancer therapy. Disruption of its pathway leads to increased cell sensitivity and progressive bone marrow failure.
The FANCD2 antibody is routinely used in the study of cancer cell lines. FANCD2 antibody products are selective for human FANCD2, and are used in numerous cancer assays. The FANCD2 antibody is of particular use in Western blot assays.
The PARP Antibody
PARP is involved in DNA repair following environmental stress. It is cleaved by a number of caspase proteins in vitro, including Caspase-3. PARP cleavage is a useful marker in cells subjected to apoptosis.
PARP antibody detects PARP1 at all cleavage stages, both as a full-length protein and as cleavage fragments.
The RAD51 Antibody
The RAD51 protein plays a major role in the repair of double strand DNA breakages. It reacts with the BRCA1 and BRCA2 proteins, and this interaction is thought to be important to DNA damage cell response.
RAD51 alteration, and inactivation of BRCA2, are linked to breast cancer development. The RAD51 antibody is used in studies of both of these proteins. Both polyclonal and monoclonal RAD51 antibody products are available from Novus Biologicals, purified from a range of mammalian sera. In humans, the RAD51 antibody reacts with the recumbent full-length protein.
As with all of our products, the RAD51 antibodies that we supply come with full technical data and are guaranteed to work in the applications and species stated on the datasheet. We aim to provide competitively priced, high quality antibodies to research facilities across the globe.
Non-homologous End-joining (NHEJ)
Non-homologous end-joining (NHEJ) is one mechanism used in the repair of DNA double-strand breaks (DSB). NHEJ is referred to as 'non-homologous' because the broken ends are directly ligated without the need for a homologous template, as is necessary for homologous recombination. NHEJ is evolutionarily conserved throughout all kingdoms of life and is the predominant DSB repair pathway in many organisms. This mechanism typically utilizes short homologous DNA sequences (microhomologies) to guide repair. Microhomologies in the single-stranded overhangs that are often present on the ends of DSB are used to promote restorative repair. When these overhangs are compatible, NHEJ almost always repairs the break accurately with no sequence loss. Imprecise repair leading to the loss of nucleotides can also occur, but is much less common. The NHEJ pathway is also responsible for fusing the ends of chromosomes that have undergone telomere failure.
Nucleotide Excision Repair (NER)
Nucleotide excision repair (NER) is an important DNA repair mechanism by which the cell repairs DNA damage occurring to bases. Base damage can be caused by a variety of sources including chemicals and UV light. NER is the mechanism by which the cell can prevent unwanted mutations by removing the majority of UV-induced DNA damage (mostly in the form of thymine dimmers and 6-4-photoproducts). The importance of this repair mechanism is evidenced by the severe human diseases that result from in-born genetic mutations of NER proteins, including Xeroderma pigmentosum and Cockayne's syndrome. NER recognizes bulky distortions in the shape of the DNA double helix. Recognition of these distortions leads to the removal of a short single-stranded DNA segment that includes the lesion, creating a single-stranded gap in the DNA. This gap is subsequently filed in by DNA polymerase, using the undamaged strand as a template.
Homologous Recombination (HR)
Homologous recombination (HR) is one mechanism used in the repair of double-strand breaks (DSB) in DNA. In the process of HR, a DSB is repaired by copying the missing information from the sister chromatid or homologous chromosome, resulting in the exact restoration of DNA.
Direct Reversal of DNA as a Method to Repair Damage
Direct reversal of DNA damage is one repair mechanism used to restore damaged DNA. Although this is the most energy efficient method, few types of damaged DNA are repaired in this way. The formation of pyrimidine dimmers, the major type of damage caused by UV light, distorts the double helix and blocks transcription or replication past the damaged site. The process of photoreactivation causes direct reversal of the dimerized reaction, thus the original pyrimidine bases are restored. Direct reversal of O6 adducts caused by chemotherapy agents is accomplished in mammalian cells by the protein O6-methylguanine DNA methyltransferase (MGMT). Some tumors overexpress MGMT and are resistance to alkylator therapy.