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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] |
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] |
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] |
CHEK1
Checkpoint kinase 1, commonly referred to as Chk1, is a serine/threonine-specific protein kinase that, in humans, is encoded by the ''CHEK1'' gene. Chk1 coordinates the DNA damage response (DDR) and cell cycle checkpoint response. Activation of Chk1 results in the initiation of cell cycle checkpoints, cell cycle arrest, DNA repair and cell death to prevent damaged cells from progressing through the cell cycle. Discovery In 1993, Beach and associates initially identified Chk1 as a serine/threonine kinase which regulates the G2/M phase transition in fission yeast. Constitutive expression of Chk1 in fission yeast was shown to induce cell cycle arrest. The same gene called Rad27 was identified in budding yeast by Carr and associates. In 1997, homologs were identified in more complex organisms including the fruit fly, human and mouse. Through these findings, it is apparent Chk1 is highly conserved from yeast to humans. Structure Human Chk1 is located on chromosome 11 on the cytogenic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VAV1
Proto-oncogene vav is a protein that in humans is encoded by the ''VAV1'' gene. Function The protein encoded by this proto-oncogene is a member of the Dbl family of guanine nucleotide exchange factors (GEF) for the Rho family of GTP binding proteins. The protein is important in hematopoiesis, playing a role in T-cell and B-cell development and activation. This particular GEF has been identified as the specific binding partner of Nef proteins from HIV-1. Coexpression and binding of these partners initiates profound morphological changes, cytoskeletal rearrangements and the JNK/SAPK signaling cascade, leading to increased levels of viral transcription and replication. Interactions VAV1 has been shown to interact with: * ARHGDIB, * Abl gene, * Cbl gene * EZH2, * Grb2, * JAK2, * Ku70, * LAT, * LCP2, * MAPK1, * PIK3R1, * PLCG1, * PRKCQ, * S100B, * SHB, * SIAH2, and * Syk Tyrosine-protein kinase SYK, also known as spleen tyrosine kinase, is an enzyme which in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telomerase Reverse Transcriptase
Telomerase reverse transcriptase (abbreviated to TERT, or hTERT in humans) is a catalytic subunit of the enzyme telomerase, which, together with the telomerase RNA component (TERC), comprises the most important unit of the telomerase complex. Telomerases are part of a distinct subgroup of RNA-dependent polymerases. Telomerase lengthens telomeres in DNA strands, thereby allowing senescent cells that would otherwise become postmitotic and undergo apoptosis to exceed the Hayflick limit and become potentially immortal, as is often the case with cancerous cells. To be specific, TERT is responsible for catalyzing the addition of nucleotides in a TTAGGG sequence to the ends of a chromosome's telomeres. This addition of repetitive DNA sequences prevents degradation of the chromosomal ends following multiple rounds of replication. hTERT absence (usually as a result of a chromosomal mutation) is associated with the disorder Cri du chat. Function Telomerase is a ribonucleoprotein p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TERF2
Telomeric repeat-binding factor 2 is a protein that is present at telomeres throughout the cell cycle. It is also known as TERF2, TRF2, and TRBF2, and is encoded in humans by the ''TERF2'' gene. It is a component of the shelterin nucleoprotein complex and a second negative regulator of telomere length, playing a key role in the protective activity of telomeres. It was first reported in 1997 in the lab of Titia de Lange, where a DNA sequence similar, but not identical, to TERF1 was discovered, with respect to the Myb-domain. De Lange isolated the new Myb-containing protein sequence and called it TERF2. Structure and domains TERF2 has a similar structure to that of TERF1. Both proteins carry a C-terminus Myb motif and large TERF1-related dimerization domains near their N-terminus. However, both proteins exist exclusively as homodimers and do not heterodimerize with each other, as proven by co-immunoprecipitation assay analysis. Also, TERF2 has a basic N-terminus, differing fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
RPA2
RPA may refer to: Companies * RPA (Rubin Postaer and Associates), advertising agency, Santa Monica, California, US * Republic Airways, ICAO code: RPA Political groups * Republican Party of Arkansas, the affiliate of the Republican Party in Arkansas * Republican Party of Armenia, a national conservative political party in Armenia * Republican Party of Australia, a minor political party * Revolutionary Proletarian Army, a militant communist organization in the Philippines * Richmond Progressive Alliance, Contra Costa County, California, US * Rural Payments Agency of the UK Department for Environment, Food and Rural Affairs * Rwandan Patriotic Army, predecessor of the Rwandan Defence Forces Organizations * Railway Procurement Agency, Ireland * Rajasthan Police Academy, India * Regional Plan Association, New York, US * Register of Professional Archaeologists * Royal Prince Alfred Hospital, Sydney, Australia * Rugby Players' Association, England Media * ''RPA'' (TV series), Austr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PTTG1
Securin is a protein that in humans is encoded by the ''PTTG1'' gene. Function The encoded protein is a homolog of yeast securin proteins, which prevent separins from promoting sister chromatid separation. It is an anaphase-promoting complex (APC) substrate that associates with a separin until activation of the APC. The gene product has transforming activity in vitro and tumorigenic activity in vivo, and the gene is highly expressed in various tumors. The gene product contains 2 PXXP motifs, which are required for its transforming and tumorigenic activities, as well as for its stimulation of basic fibroblast growth factor expression. It also contains a destruction box (D box) that is required for its degradation by the APC. The acidic C-terminal region of the encoded protein can act as a transactivation domain. The gene product is mainly a cytosolic protein, although it partially localizes in the nucleus. Interactions PTTG1 has been shown to interact with: * DNAJA1, * Ku70 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PCNA
Proliferating cell nuclear antigen (PCNA) is a DNA clamp that acts as a processivity factor for DNA polymerase δ in eukaryotic cells and is essential for replication. PCNA is a homotrimer and achieves its processivity by encircling the DNA, where it acts as a scaffold to recruit proteins involved in DNA replication, DNA repair, chromatin remodeling and epigenetics. Many proteins interact with PCNA via the two known PCNA-interacting motifs PCNA-interacting peptide (PIP) box and AlkB homologue 2 PCNA interacting motif (APIM). Proteins binding to PCNA via the PIP-box are mainly involved in DNA replication whereas proteins binding to PCNA via APIM are mainly important in the context of genotoxic stress. Function The protein encoded by this gene is found in the nucleus and is a cofactor of DNA polymerase delta. The encoded protein acts as a homotrimer and helps increase the processivity of leading strand synthesis during DNA replication. In response to DNA damage, this protein is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutrophil Cytosolic Factor 4
Neutrophil cytosol factor 4 is a protein that in humans is encoded by the ''NCF4'' gene. Function The protein encoded by this gene is a cytosolic regulatory component of the superoxide-producing phagocyte NADPH-oxidase, a multicomponent enzyme system important for host defense. This protein is preferentially expressed in cells of myeloid lineage. It interacts primarily with neutrophil cytosolic factor 2 (NCF2/p67-phox) to form a complex with neutrophil cytosolic factor 1 (NCF1/p47-phox), which further interacts with the small G protein RAC1 and translocates to the membrane upon cell stimulation. This complex then activates flavocytochrome b, the membrane-integrated catalytic core of the enzyme system. The PX domain of this protein can bind phospholipid products of the PI(3) kinase, which suggests its role in PI(3) kinase-mediated signaling events. The phosphorylation of this protein was found to negatively regulate the enzyme activity. Alternatively spliced transcript variants en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NCOA6
Nuclear receptor coactivator 6 is a protein that in humans is encoded by the ''NCOA6'' gene. Function The protein encoded by this gene is a transcriptional coactivator that can interact with nuclear hormone receptors to enhance their transcriptional activator functions. The encoded protein has been shown to be involved in the hormone-dependent coactivation of several receptors, including prostanoid, retinoid, vitamin D3, thyroid hormone, and steroid receptors. The encoded protein may also act as a general coactivator since it has been shown to interact with some basal transcription factors, histone acetyltransferases, and methyltransferases. Interactions NCOA6 has been shown to interact with: * ASCL2 and * Activating transcription factor 2, * Androgen receptor, * CREB-binding protein, * DNA-PKcs, * E2F1, * EP300, * Estrogen receptor alpha, * Estrogen receptor beta, * HBXIP, * HIST2H3C, * HSF1, * Ku70, * Ku80, * Liver X receptor beta, * MLL3, * RBBP5, * Reti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MRE11A
Double-strand break repair protein MRE11 is an enzyme that in humans is encoded by the ''MRE11'' gene. The gene has been designated ''MRE11A'' to distinguish it from the pseudogene ''MRE11B'' that is nowadays named ''MRE11P1''. Function This gene encodes a nuclear protein involved in homologous recombination, telomere length maintenance, and DNA double-strand break repair. By itself, the protein has 3' to 5' exonuclease activity and endonuclease activity. The protein forms a complex with the RAD50 homolog; this complex is required for nonhomologous joining of DNA ends and possesses increased single-stranded DNA endonuclease and 3' to 5' exonuclease activities. In conjunction with a DNA ligase, this protein promotes the joining of noncomplementary ends in vitro using short homologies near the ends of the DNA fragments. This gene has a pseudogene on chromosome 3. Alternative splicing of this gene results in two transcript variants encoding different isoforms. Orthologs Mre11, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
