DNA Repair

The dynamic use of a PCNA antibody in fish, porcine and primate species

Proliferating cell nuclear antigen (PCNA) plays a crucial role in nucleic acid metabolism as it pertains to DNA replication and repair.  Most noted for its activation of subunits of DNA polymerase, it has also been found to interact with cell-cycle progression proteins.  Modifications of PCNA as a result of cellular response put PCNA in a pivotal position with DNA replication, DNA damage, and chromatin structure and function.  In response to DNA damage, PCNA is ubiquitinated and becomes part of the RAD-6 dependent DNA repair pathway, where it acts as a substrate with a variety of p

The recent relationship of BRCA1 and 53BP1

The p53-binding protein 1 (53BP1) is a DNA damage response factor, which is recruited to nuclear structures at the site of DNA damage.  DNA double-strand breaks (DSBs) are mutations that are detrimental to cell viability and genome stability, and must be repaired either through homologous recombination (HR) or non-homologous end joining (NHEJ). 53BP1 specifically promotes both NHEJ as well as the inhibition of HR repair, yet the decision making on a molecular level between these two routes not clearly understood.

FANCD2 and DNA damage repair

Fanconi anemia (FA) is a genetically inherited disorder that yields cytogenetic instability, hypersensitivity to DNA crosslinking compounds and defective DNA repair. A variety of genes have been identified within the FA pathway that are referred to as the Fanconi anemia complementation group.  One member of this group, FANCD2, is monoubiquitinated in response to DNA damage.  At this point, FANCD2 specifically localizes to the nucleus to represent the site of DNA repair, often times to the DNA replication fork.

Using SCP3/SYCP3 Antibodies as Meiosis Markers in Gametogenesis and DNA Repair Studies

The synaptonemal complex (SC) is a protein structure that forms during the synapsis of homologous chromosomes during meiosis. This structure is involved in the processes of chromosome synapsis, genetic recombination and subsequent chromosome segregation, and is essential for gametogenesis.

The role of PARP-1 in the repair of single stranded break (SSB)

PARPs (poly ADP ribose polymerases) are DNA repair enzymes that promote single stranded break (SSB) repair by binding to DNA at the sites of SSBs and recruiting repair machinery. In humans, the PARP superfamily consists of 17 members, of which five play known roles in SSB repair. PARP-1, the most well-studied family member, is required for base excision repair and is thought to be responsible for 90% of PARP activity (5).

GAPDH - A "housekeeping" gene with diverse functions in cellular homeostasis

Glyceraldehyde 3-phosphate dehydrogenase (GAPDH) is a well-known housekeeping gene with functions in glycolysis. Many biologists are familiar with the gene and use GAPDH antibodies for a loading control when performing west blots. However, this primarily cytoplasmic protein is an essential metabolic regulator and has been shown to be involved in a variety of cellular processes like DNA repair, membrane fusion, and cell death (1). Cytoplasmic GAPDH exists as a tetramer and normally mediates the formation of ATP and NADH during glycolysis (1).

Dnmt1 - A ubiquitous DNA methyltransferase

The Dnmt1 enzyme is a member of the C5-methyltransferase family responsible for repairing cytosines in double-stranded DNA (dsDNA). This enzyme uses a nucleophilic attack mechanism and is the most abundantly found mammalian DNA methyltransferase. It primarily acts upon CpG residues and prefers hemimethylated residues, but can also methylating unmethylated DNA. The cell relies upon Dnmt1 as its key methylation maintenance enzyme both for DNA replication and repair as well as for de novo methylation during somatic cell development and differentiation.

PCNA (Proliferating cell nuclear antigen, polymerase delta auxiliary protein)

PCNA is a nuclear protein essential for DNA replication as well as DNA excision and mismatch repair pathways. It coordinates the recruitment and association of needed components during both of these processes, both of which are essential for cell cycle regulation and cell response to stress.  Through the symmetric association of three identical monomers, PCNA forms a toroidal, ring-shaped structure that encircles DNA. This serves as the scaffold upon which polymerases and other proteins dock and associate.

FANCD2: A big component of the DNA repair crew

The genetic disorder known as Fanconi anemia (FANC) is a heterogeneous, autosomal-recessive cancer susceptibility condition characterized by a wide array of symptoms. These include congenital malformations, progressive bone marrow failure, DNA-damage hypersensitivity, and genome instability. The protein FANCD2 is a subunit of the protein complex involved in cellular resistance to DNA cross-linking and DNA synthesis arrest triggered by ionizing radiation (IR).

53BP1 - DNA damage is no fun

The 53BP1 (p53 binding protein 1) was initially believed to be a p53 transcriptional enhancing partner, but it has now been established as an ataxia telangiectasia mutated (ATM) substrate. As a late DNA damage response (DDR) marker, 53BP1 appears during the telophase and cytokinesis phase of mitotic mammalian cells1.