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Tax Gene Product
A Tax Gene Product (Tax) is a nuclear protein that has a molecular weight of about 37,000 to 40,000 daltons. Tax gene Tax is produced by members of the retroviral family primate T-lymphotropic virus, which are classified as Deltaretroviruses. This includes Human T-lymphotrophic viruses (HTLVs), bovine leukaemia virus (BLV) and simian T-lymphotropic viruses ( STLVs). The tax protein produced from HTLV-1 and HTLV-2 have been most extensively studied. The gene for Tax is found within the pX region between the ''env'' gene and one of the long terminal repeats of the viral genome; which is where the name Tax comes from (transactivator from the X-gene region). Tax acts as a transactivator, causing the transcription (production of mRNA from genetic code) of viral proteins in the long terminal repeat that are essential for replication. Role in disease HTLV-1 causes an aggressive form of leukaemia: adult T cell leukaemia (ATL), and Tax has largely been implicated in the oncogenic potenti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Protein
A nuclear protein is a protein found in the cell nucleus. Proteins are transported inside the nucleus with the help of the nuclear pore complex, which acts a barrier between cytoplasm and nuclear membrane. The import and export of proteins through the nuclear pore complex plays a fundamental role in gene regulation and other biological functions. References External links *http://npd.hgu.mrc.ac.uk/user/about Cell nucleus {{Protein-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adult T-cell Leukemia/lymphoma
Adult T-cell leukemia/lymphoma (ATL or ATLL) is a rare cancer of the immune system's T-cells caused by human T cell leukemia/lymphotropic virus type 1 (HTLV-1). All ATL cells contain integrated HTLV-1 provirus further supporting that causal role of the virus in the cause of the neoplasm. A small amount of HTLV-1 individuals progress to develop ATL with a long latency period between infection and ATL development. ATL is categorized into 4 subtypes: acute, smoldering, lymphoma-type, chronic. Acute and Lymphoma-type are known to particularity be aggressive with poorer prognosis. Globally, the retrovirus HTLV-1 is estimated to infect 20 million people with the incidence of ATL approximately 0.05 per 100,000 with endemic regions such as regions of Japan, as high as 27 per 100,000. However, cases have increased in non-endemic regions with highest incidence of HTLV-1 in southern/northern islands of Japan, Caribbean, Central and South America, intertropical Africa, Romania, northern Iran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aneuploidy
Aneuploidy is the presence of an abnormal number of chromosomes in a cell, for example a human cell having 45 or 47 chromosomes instead of the usual 46. It does not include a difference of one or more complete sets of chromosomes. A cell with any number of complete chromosome sets is called a ''euploid'' cell. An extra or missing chromosome is a common cause of some genetic disorders. Some cancer cells also have abnormal numbers of chromosomes. About 68% of human solid tumors are aneuploid. Aneuploidy originates during cell division when the chromosomes do not separate properly between the two cells (nondisjunction). Most cases of aneuploidy in the autosomes result in miscarriage, and the most common extra autosomal chromosomes among live births are 21, 18 and 13. Chromosome abnormalities are detected in 1 of 160 live human births. Autosomal aneuploidy is more dangerous than sex chromosome aneuploidy, as autosomal aneuploidy is almost always lethal to embryos that cease develo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mitosis, or meiosis or other types of damage to DNA (such as pyrimidine dimers caused by exposure to ultraviolet radiation), which then may undergo error-prone repair (especially microhomology-mediated end joining), cause an error during other forms of repair, or cause an error during replication (translesion synthesis). Mutations may also result from insertion or deletion of segments of DNA due to mobile genetic elements. Mutations may or may not produce detectable changes in the observable characteristics (phenotype) of an organism. Mutations play a part in both normal and abnormal biological processes including: evolution, cancer, and the development of the immune system, including junctional diversity. Mutation is the ultimate source of all ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nucleotide Excision Repair
Nucleotide excision repair is a DNA repair mechanism. DNA damage occurs constantly because of chemicals (e.g. intercalating agents), radiation and other mutagens. Three excision repair pathways exist to repair single stranded DNA damage: Nucleotide excision repair (NER), base excision repair (BER), and DNA mismatch repair (MMR). While the BER pathway can recognize specific non-bulky lesions in DNA, it can correct only damaged bases that are removed by specific glycosylases. Similarly, the MMR pathway only targets mismatched Watson-Crick base pairs. Nucleotide excision repair (NER) is a particularly important excision mechanism that removes DNA damage induced by ultraviolet light (UV). UV DNA damage results in bulky DNA adducts - these adducts are mostly thymine dimers and 6,4-photoproducts. Recognition of the damage leads to removal of a short single-stranded DNA segment that contains the lesion. The undamaged single-stranded DNA remains and DNA polymerase uses it as a templa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Base Excision Repair
Base excision repair (BER) is a cellular mechanism, studied in the fields of biochemistry and genetics, that repairs damaged DNA throughout the cell cycle. It is responsible primarily for removing small, non-helix-distorting base lesions from the genome. The related nucleotide excision repair pathway repairs bulky helix-distorting lesions. BER is important for removing damaged bases that could otherwise cause mutations by mispairing or lead to breaks in DNA during replication. BER is initiated by DNA glycosylases, which recognize and remove specific damaged or inappropriate bases, forming AP sites. These are then cleaved by an AP endonuclease. The resulting single-strand break can then be processed by either short-patch (where a single nucleotide is replaced) or long-patch BER (where 2–10 new nucleotides are synthesized). Lesions processed by BER Single bases in DNA can be chemically damaged by a variety of mechanisms, the most common ones being deamination, oxidation, ... [...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] |
Cell Cycle
The cell cycle, or cell-division cycle, is the series of events that take place in a cell that cause it to divide into two daughter cells. These events include the duplication of its DNA (DNA replication) and some of its organelles, and subsequently the partitioning of its cytoplasm, chromosomes and other components into two daughter cells in a process called cell division. In cells with nuclei ( eukaryotes, i.e., animal, plant, fungal, and protist cells), the cell cycle is divided into two main stages: interphase and the mitotic (M) phase (including mitosis and cytokinesis). During interphase, the cell grows, accumulating nutrients needed for mitosis, and replicates its DNA and some of its organelles. During the mitotic phase, the replicated chromosomes, organelles, and cytoplasm separate into two new daughter cells. To ensure the proper replication of cellular components and division, there are control mechanisms known as cell cycle checkpoints after each of the key steps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serum Response Factor
Serum response factor, also known as SRF, is a transcription factor protein. Function Serum response factor is a member of the MADS (MCM1, Agamous, Deficiens, and SRF) box superfamily of transcription factors. This protein binds to the serum response element (SRE) in the promoter region of target genes. This protein regulates the activity of many immediate early genes, for example c-fos, and thereby participates in cell cycle regulation, apoptosis, cell growth, and cell differentiation. This gene is the downstream target of many pathways; for example, the mitogen-activated protein kinase pathway (MAPK) that acts through the ternary complex factors (TCFs). SRF is important during the development of the embryo, as it has been linked to the formation of mesoderm. In the fully developed mammal, SRF is crucial for the growth of skeletal muscle. Interaction of SRF with other proteins, such as steroid hormone receptors, may contribute to regulation of muscle growth by steroids. Int ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AP-1 (transcription Factor)
Activator protein 1 (AP-1) is a transcription factor that regulates gene expression in response to a variety of stimuli, including cytokines, growth factors, stress, and bacterial and viral infections. AP-1 controls a number of cellular processes including differentiation, proliferation, and apoptosis. The structure of AP-1 is a heterodimer composed of proteins belonging to the c-Fos, c-Jun, ATF and JDP families. History AP-1 was first discovered as a TPA-activated transcription factor that bound to a cis-regulatory element of the human metallothionein IIa ( hMTIIa) promoter and SV40. The AP-1 binding site was identified as the 12-O-Tetradecanoylphorbol-13-acetate ( TPA) response element (TRE) with the consensus sequence 5’-TGA G/C TCA-3’. The AP-1 subunit Jun was identified as a novel oncoprotein of avian sarcoma virus, and Fos-associated p39 protein was identified as the transcript of the cellular Jun gene. Fos was first isolated as the cellular homologue of two ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NF-κB
Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a protein complex that controls transcription of DNA, cytokine production and cell survival. NF-κB is found in almost all animal cell types and is involved in cellular responses to stimuli such as stress, cytokines, free radicals, heavy metals, ultraviolet irradiation, oxidized LDL, and bacterial or viral antigens. NF-κB plays a key role in regulating the immune response to infection. Incorrect regulation of NF-κB has been linked to cancer, inflammatory and autoimmune diseases, septic shock, viral infection, and improper immune development. NF-κB has also been implicated in processes of synaptic plasticity and memory. Discovery NF-κB was discovered by Ranjan Sen in the lab of Nobel laureate David Baltimore via its interaction with an 11-base pair sequence in the immunoglobulin light-chain enhancer in B cells. Later work by Alexander Poltorak and Bruno Lemaitre in mice and ''Drosophila'' frui ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
