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CYREN (protein)
Cell cycle regulator of non-homologous end joining is a protein that in humans is encoded by the CYREN gene. It prevents classical non-homologous end joining, a method of repair of double-stranded DNA breaks. This protein is therefore important in regulating DNA repair. When alternatively spliced, is predicted to produce three different micropeptides. * MRI-1 was previously found to be a modulator of retrovirus infection. * MRI-2 may be important in non-homologous end joining (NHEJ) of DNA double strand breaks. In Co-Immunoprecipitation experiments, MRI-2 bound to Ku70 and Ku80 Ku80 is a protein that, in humans, is encoded by the ''XRCC5'' gene. Together, Ku70 and Ku80 make up the Ku heterodimer, which binds to DNA double-strand break ends and is required for the non-homologous end joining (NHEJ) pathway of DNA repair ..., two subunits of Ku, which play a major role in the NHEJ pathway. *MRI-3 References DNA repair {{Protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Non-homologous End Joining
Non-homologous end joining (NHEJ) is a pathway that repairs double-strand breaks in DNA. NHEJ is referred to as "non-homologous" because the break ends are directly ligated without the need for a homologous template, in contrast to homology directed repair(HDR), which requires a homologous sequence to guide repair. NHEJ is active in both non-dividing and proliferating cells, while HDR is not readily accessible in non-dividing cells. The term "non-homologous end joining" was coined in 1996 by Moore and Haber. NHEJ is typically guided by short homologous DNA sequences called microhomologies. These microhomologies are often present in single-stranded overhangs on the ends of double-strand breaks. When the overhangs are perfectly compatible, NHEJ usually repairs the break accurately. Imprecise repair leading to loss of nucleotides can also occur, but is much more common when the overhangs are not compatible. Inappropriate NHEJ can lead to translocations and telomere fusion, hallmarks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Repair
DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as radiation can cause DNA damage, resulting in tens of thousands of individual molecular lesions per cell per day. Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell's ability to transcribe the gene that the affected DNA encodes. Other lesions induce potentially harmful mutations in the cell's genome, which affect the survival of its daughter cells after it undergoes mitosis. As a consequence, the DNA repair process is constantly active as it responds to damage in the DNA structure. When normal repair processes fail, and when cellular apoptosis does not occur, irreparable DNA damage may occur, including double-strand breaks and DNA crosslinkages (interstrand crosslinks or ICLs). This can eventually lead to malignant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micropeptides
Micropeptides (also referred to as microproteins) are polypeptides with a length of less than 100-150 amino acids that are encoded by short open reading frames (sORFs). In this respect, they differ from many other active small polypeptides, which are produced through the posttranslational cleavage of larger polypeptides. In terms of size, micropeptides are considerably shorter than "canonical" proteins, which have an average length of 330 and 449 amino acids in prokaryotes and eukaryotes, respectively. Micropeptides are sometimes named according to their genomic location. For example, the translated product of an upstream open reading frame (uORF) might be called a uORF-encoded peptide (uPEP). Micropeptides lack an N-terminal signaling sequences, suggesting that they are likely to be localized to the cytoplasm. However, some micropeptides have been found in other cell compartments, as indicated by the existence of transmembrane micropeptides. They are found in both prokaryotes and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ku70
Ku70 is a protein that, in humans, is encoded by the ''XRCC6'' gene. Function Together, Ku70 and Ku80 make up the Ku heterodimer, which binds to DNA double-strand break ends and is required for the non-homologous end joining (NHEJ) pathway of DNA repair. It is also required for V(D)J recombination, which utilizes the NHEJ pathway to promote antigen diversity in the mammalian immune system. In addition to its role in NHEJ, Ku is also required for telomere length maintenance and subtelomeric gene silencing. Ku was originally identified when patients with systemic lupus erythematosus were found to have high levels of autoantibodies to the protein. Aging Mouse embryonic stem cells with homozygous Ku70 mutations, that is Ku70−/− cells, have markedly increased sensitivity to ionizing radiation compared to heterozygous Ku70+/− or wild-type Ku70+/+ embryonic stem cells. Mutant mice deficient in Ku70 exhibit early aging. Using several specific criteria of aging, the mutant m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ku80
Ku80 is a protein that, in humans, is encoded by the ''XRCC5'' gene. Together, Ku70 and Ku80 make up the Ku heterodimer, which binds to DNA double-strand break ends and is required for the non-homologous end joining (NHEJ) pathway of DNA repair. It is also required for V(D)J recombination, which utilizes the NHEJ pathway to promote antigen diversity in the mammalian immune system. In addition to its role in NHEJ, Ku is required for telomere length maintenance and subtelomeric gene silencing. Ku was originally identified when patients with systemic lupus erythematosus were found to have high levels of autoantibodies to the protein. Nomenclature Ku80 has been referred to by several names including: * Lupus Ku autoantigen protein p80 * ATP-dependent DNA helicase 2 subunit 2 * X-ray repair complementing defective repair in Chinese hamster cells 5 * X-ray repair cross-complementing 5 (XRCC5) Epigenetic repression The protein expression level of Ku80 can be repressed by epig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ku (protein)
Ku is a dimeric protein complex that binds to DNA double-strand break ends and is required for the non-homologous end joining (NHEJ) pathway of DNA repair. Ku is evolutionarily conserved from bacteria to humans. The ancestral bacterial Ku is a homodimer (two copies of the same protein bound to each other). Eukaryotic Ku is a heterodimer of two polypeptides, Ku70 (XRCC6) and Ku80 (XRCC5), so named because the molecular weight of the human Ku proteins is around 70 kDa and 80 kDa. The two Ku subunits form a basket-shaped structure that threads onto the DNA end. Once bound, Ku can slide down the DNA strand, allowing more Ku molecules to thread onto the end. In higher eukaryotes, Ku forms a complex with the DNA-dependent protein kinase catalytic subunit (DNA-PKcs) to form the full DNA-dependent protein kinase, DNA-PK. Ku is thought to function as a molecular scaffold to which other proteins involved in NHEJ can bind, orienting the double-strand break for ligation. The Ku70 and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
