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XRCC2
DNA repair protein XRCC2 is a protein that in humans is encoded by the ''XRCC2'' gene. Function This gene encodes a member of the RecA/Rad51-related protein family that participates in homologous recombination to maintain chromosome stability and repair DNA damage. This gene is involved in the repair of DNA double-strand breaks by homologous recombination and it functionally complements Chinese hamster irs1, a repair-deficient mutant that exhibits hypersensitivity to a number of different DNA-damaging agents. The XRCC2 protein is one of five human paralogs of RAD51, including RAD51B ( RAD51L1), RAD51C (RAD51L2), RAD51D ( RAD51L3), XRCC2 and XRCC3. They each share about 25% amino acid sequence identity with RAD51 and each other. The RAD51 paralogs are all required for efficient DNA double-strand break repair by homologous recombination and depletion of any paralog results in significant decreases in homologous recombination frequency. XRCC2 forms a four-part complex with thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAD51C
RAD51 homolog C (S. cerevisiae), also known as RAD51C, is a protein which in humans is encoded by the ''RAD51C'' gene. Function The RAD51C protein is one of five paralogs of RAD51, including RAD51B ( RAD51L1), RAD51C (RAD51L2), RAD51D ( RAD51L3), XRCC2 and XRCC3. They each share about 25% amino acid sequence identity with RAD51 and each other. The RAD51 paralogs are all required for efficient DNA double-strand break repair by homologous recombination and depletion of any paralog results in significant decreases in homologous recombination frequency. RAD51C forms two distinct complexes with other related paralogs: BCDX2 (RAD51B-RAD51C-RAD51D-XRCC2) and CX3 (RAD51C-XRCC3). These two complexes act at two different stages of homologous recombinational DNA repair. The BCDX2 complex is responsible for RAD51 recruitment or stabilization at damage sites. The BCDX2 complex appears to act by facilitating the assembly or stability of the RAD51 nucleoprotein filament. The CX3 compl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
XRCC3
DNA repair protein XRCC3 is a protein that in humans is encoded by the ''XRCC3'' gene. Function This gene encodes a member of the RecA/Rad51-related protein family that participates in homologous recombination to maintain chromosome stability and repair DNA damage. This gene functionally complements Chinese hamster irs1SF, a repair-deficient mutant that exhibits hypersensitivity to a number of different DNA-damaging agents and is chromosomally unstable. A rare microsatellite polymorphism in this gene is associated with cancer in patients of varying radiosensitivity. The XRCC3 protein is one of five paralogs of RAD51, including RAD51B ( RAD51L1), RAD51C (RAD51L2), RAD51D ( RAD51L3), XRCC2 and XRCC3. They each share about 25% amino acid sequence identity with RAD51 and each other. The RAD51 paralogs are all required for efficient DNA double-strand break repair by homologous recombination and depletion of any paralog results in significant decreases in homologous recombination f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAD51
DNA repair protein RAD51 homolog 1 is a protein encoded by the gene ''RAD51''. The enzyme encoded by this gene is a member of the RAD51 protein family which assists in repair of DNA double strand breaks. RAD51 family members are homologous to the bacterial RecA, Archaeal RadA and yeast Rad51. The protein is highly conserved in most eukaryotes, from yeast to humans. Variants Two alternatively spliced transcript variants of this gene, which encode distinct proteins, have been reported. Transcript variants utilizing alternative polyA signals exist. Family In mammals, seven recA-like genes have been identified: Rad51, Rad51L1/B, Rad51L2/C, Rad51L3/D, XRCC2, XRCC3, and DMC1/Lim15. All of these proteins, with the exception of meiosis-specific DMC1, are essential for development in mammals. Rad51 is a member of thRecA-like NTPases Function In humans, RAD51 is a 339-amino acid protein that plays a major role in homologous recombination of DNA during double strand b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAD51L3
DNA repair protein RAD51 homolog 4 is a protein that in humans is encoded by the ''RAD51L3'' gene. Function The protein encoded by this gene is a member of the RAD51 protein family. RAD51 family members are highly similar to bacterial RecA and Saccharomyces cerevisiae Rad51, which are known to be involved in the homologous recombination and repair of DNA. This protein forms a complex with several other members of the RAD51 family, including RAD51L1, RAD51L2, and XRCC2. The protein complex formed with this protein has been shown to catalyze homologous pairing between single- and double-stranded DNA, and is thought to play a role in the early stage of recombinational repair of DNA. Several alternatively spliced transcript variants of this gene have been described, but the biological validity of some of them has not been determined. Interactions RAD51L3 has been shown to interact with: * Bloom syndrome protein, * RAD51C, and * XRCC2 DNA repair protein XRCC2 is a protein that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RAD51L1
DNA repair protein RAD51 homolog 2 is a protein that in humans is encoded by the ''RAD51L1'' gene. Function The protein encoded by this gene is a member of the RAD51 protein family. RAD51 family members are evolutionarily conserved proteins essential for DNA repair by homologous recombination. This protein has been shown to form a stable heterodimer with the family member RAD51C, which further interacts with the other family members, such as RAD51, XRCC2, and XRCC3. Overexpression of this gene was found to cause cell cycle G1 delay and cell apoptosis, which suggested a role of this protein in sensing DNA damage. At least three alternatively spliced transcript variants encoding distinct isoforms have been observed. Interactions RAD51L1 has been shown to interact with RAD51C RAD51 homolog C (S. cerevisiae), also known as RAD51C, is a protein which in humans is encoded by the ''RAD51C'' gene. Function The RAD51C protein is one of five paralogs of RAD51, including RAD51B ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bloom Syndrome Protein
Bloom syndrome protein is a protein that in humans is encoded by the ''BLM'' gene and is not expressed in Bloom syndrome. The Bloom syndrome gene product is related to the RecQ subset of DExH box-containing DNA helicases and has both DNA-stimulated ATPase and ATP-dependent DNA helicase activities. Mutations causing Bloom syndrome delete or alter helicase motifs and may disable the 3' → 5' helicase activity. The normal protein may act to suppress inappropriate homologous recombination. Meiosis Genetic recombination, Recombination during meiosis is often initiated by a DNA double-strand break (DSB). During recombination, sections of DNA at the Directionality (molecular biology), 5' ends of the break are cut away in a process called resection. In the strand invasion step that follows, an overhanging Directionality (molecular biology), 3' end of the broken DNA molecule then "invades" the DNA of an homologous chromosome that is not broken. After strand invasion, the further sequen ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Methylation
DNA methylation is a biological process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter, DNA methylation typically acts to repress gene transcription. In mammals, DNA methylation is essential for normal development and is associated with a number of key processes including genomic imprinting, X-chromosome inactivation, repression of transposable elements, aging, and carcinogenesis. As of 2016, two nucleobases have been found on which natural, enzymatic DNA methylation takes place: adenine and cytosine. The modified bases are N6-methyladenineD. B. Dunn, J. D. Smith: ''The occurrence of 6-methylaminopurine in deoxyribonucleic acids.'' In: ''Biochem J.'' 68(4), Apr 1958, S. 627–636. PMID 13522672. ., 5-methylcytosineB. F. Vanyushin, S. G. Tkacheva, A. N. Belozersky: ''Rare bases in animal DNA.'' In: ''Nature.'' 225, 1970, S. 948–949. PMID 4391887. and N4 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epigenetics
In biology, epigenetics is the study of stable phenotypic changes (known as ''marks'') that do not involve alterations in the DNA sequence. The Greek prefix '' epi-'' ( "over, outside of, around") in ''epigenetics'' implies features that are "on top of" or "in addition to" the traditional genetic basis for inheritance. Epigenetics most often involves changes that affect the regulation of gene expression, but the term can also be used to describe any heritable phenotypic change. Such effects on cellular and physiological phenotypic traits may result from external or environmental factors, or be part of normal development. The term also refers to the mechanism of changes: functionally relevant alterations to the genome that do not involve mutation of the nucleotide sequence. Examples of mechanisms that produce such changes are DNA methylation and histone modification, each of which alters how genes are expressed without altering the underlying DNA sequence. Gene express ... [...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 malign ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Conversion
Gene conversion is the process by which one DNA sequence replaces a homologous sequence such that the sequences become identical after the conversion event. Gene conversion can be either allelic, meaning that one allele of the same gene replaces another allele, or ectopic, meaning that one paralogous DNA sequence converts another. Allelic gene conversion Allelic gene conversion occurs during meiosis when homologous recombination between heterozygotic sites results in a mismatch in base pairing. This mismatch is then recognized and corrected by the cellular machinery causing one of the alleles to be converted to the other. This can cause non-Mendelian segregation of alleles in germ cells. Nonallelic/ectopic gene conversion Recombination occurs not only during meiosis, but also as a mechanism for repair of double-strand breaks (DSBs) caused by DNA damage. These DSBs are usually repaired using the sister chromatid of the broken duplex and not the homologous chromosome, so they w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
