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Leucine-rich Nuclear Export Signal
A nuclear export signal (NES) is a short target peptide containing 4 hydrophobic residues in a protein that targets it for export from the cell nucleus to the cytoplasm through the nuclear pore complex using nuclear transport. It has the opposite effect of a nuclear localization signal, which targets a protein located in the cytoplasm for import to the nucleus. The NES is recognized and bound by exportins. NESs serve several vital cellular functions. They assist in regulating the position of proteins within the cell. Through this NESs affect transcription and several other nuclear functions that are essential to proper cell function. The export of many types of RNA from the nucleus is required for proper cellular function. The NES determines what type of pathway the varying types of RNA may use to exit the nucleus and perform their function and the NESs may effect the directionality of molecules exiting the nucleus. Structure Computer analysis of known NESs found the most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Target Peptide
Target may refer to: Physical items * Shooting target, used in marksmanship training and various shooting sports ** Bullseye (target), the goal one for which one aims in many of these sports ** Aiming point, in field artillery, fixed at a specific target * Color chart (or reference card), the reference target used in digital imaging for accurate color reproduction Places * Target, Allier, France * Target Lake, a lake in Minnesota Terms * Target market, marketing strategy ** Target audience, intended audience or readership of a publication, advertisement, or type of message * In mathematics, the target of a function is also called the codomain * Target (cricket), the total number of runs a team needs to win People * Target (rapper), stage name of Croatian hip-hop artist Nenad Šimun * DJ Target, stage name of English grime DJ Darren Joseph, member of Roll Deep * Gui-Jean-Baptiste Target (1733–1807), French lawyer Art and media * The Target, a comic book charact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G-protein
G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior. Their activity is regulated by factors that control their ability to bind to and hydrolyze guanosine triphosphate (GTP) to guanosine diphosphate (GDP). When they are bound to GTP, they are 'on', and, when they are bound to GDP, they are 'off'. G proteins belong to the larger group of enzymes called GTPases. There are two classes of G proteins. The first function as monomeric small GTPases (small G-proteins), while the second function as heterotrimeric G protein complexes. The latter class of complexes is made up of ''alpha'' (α), ''beta'' (β) and ''gamma'' (γ) subunits. In addition, the beta and gamma subunits can form a stable dimeric complex referred to as the beta-gamma complex . Heterotrimeric G proteins located within the cell are activa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CRM1
Exportin 1 (XPO1), also known as chromosomal region maintenance 1 (CRM1), is a eukaryotic protein that mediates the nuclear export of various proteins and RNAs. History XPO1 (CRM1) originally was identified in the fission yeast ''Schizosaccharomyces pombe'' in a genetic screen, and investigators determined that it was involved in control of the chromosome structure. It was later shown to be the nuclear transport receptor for cargos with leucine-rich nuclear export signals (NES). The structural details of the interaction of XPO1 with its cargos were revealed two decades after the gene was identified. Function XPO1 mediates NES-dependent protein transport. It exports several hundreds of different proteins from the nucleus. XPO1 is involved in the nuclear export of ribosomal subunits. XPO1 plays a role in export of various RNAs including U snRNAs, rRNAs (as a part of ribosomal subunits), and some mRNAs. Medical relevance XPO1 is involved in various viral infections. For exampl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karyopherin
Karyopherins are proteins involved in transporting molecules between the cytoplasm and the nucleus of a eukaryotic cell. The inside of the nucleus is called the karyoplasm (or nucleoplasm). Generally, karyopherin-mediated transport occurs through nuclear pores which acts as a gateway into and out of the nucleus. Most proteins require karyopherins to traverse the nuclear pore. Karyopherins can act as ''importins'' (i.e. helping proteins get into the nucleus) or ''exportins'' (i.e. helping proteins get out of the nucleus). They belong to the nuclear pore complex family in the transporter classification database (TCDB). Energy for transport is derived from the Ran gradient. Upon stress, several karyopherins stop shuttling between the nucleus and the cytoplasm and are sequestered in stress granules, cytoplasmic aggregates of ribonucleoprotein complexes. Importin beta Importin beta is a variety of karyopherin that facilitates the transport of cargo proteins into the nucleus. First, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein Kinase Inhibitor
A protein kinase inhibitor is a type of enzyme inhibitor that blocks the action of one or more protein kinases. Protein kinases are enzymes that phosphorylate (add a phosphate, or PO4, group) to a protein and can modulate its function. The phosphate groups are usually added to serine, threonine, or tyrosine amino acids on the protein: most kinases act on both serine and threonine, the tyrosine kinases act on tyrosine, and a number ( dual-specificity kinases) act on all three. There are also protein kinases that phosphorylate other amino acids, including histidine kinases that phosphorylate histidine residues. Phosphorylation regulates many biological processes, and protein kinase inhibitors can be used to treat diseases due to hyperactive protein kinases (including mutant or overexpressed kinases in cancer) or to modulate cell functions to overcome other disease drivers. Clinical use Kinase inhibitors such as dasatinib are often used in the treatment of cancer and infla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Adenosine Monophosphate
Cyclic adenosine monophosphate (cAMP, cyclic AMP, or 3',5'-cyclic adenosine monophosphate) is a second messenger important in many biological processes. cAMP is a derivative of adenosine triphosphate (ATP) and used for intracellular signal transduction in many different organisms, conveying the cAMP-dependent pathway. History Earl Sutherland of Vanderbilt University won a Nobel Prize in Physiology or Medicine in 1971 "for his discoveries concerning the mechanisms of the action of hormones", especially epinephrine, via second messengers (such as cyclic adenosine monophosphate, cyclic AMP). Synthesis Cyclic adenosine monophosphate, AMP is synthesized from Adenosine triphosphate, ATP by adenylate cyclase located on the inner side of the plasma membrane and anchored at various locations in the interior of the cell. Adenylate cyclase is ''activated'' by a range of signaling molecules through the activation of adenylate cyclase stimulatory G (Gs alpha subunit, Gs)-protein-coupled recep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Immunodeficiency Virus 1
The subtypes of HIV include two major types, HIV type 1 (HIV-1) and HIV type 2 (HIV-2). HIV-1 is related to viruses found in chimpanzees and gorillas living in western Africa, while HIV-2 viruses are related to viruses found in the sooty mangabey, a vulnerable West African primate. HIV-1 viruses can be further divided into groups M, N, O and P. The HIV-1 group M viruses predominate and are responsible for the AIDS pandemic. Group M can be further subdivided into subtypes based on genetic sequence data. Some of the subtypes are known to be more virulent or are resistant to different medications. Likewise, HIV-2 viruses are thought to be less virulent and transmissible than HIV-1 M group viruses, although HIV-2 is also known to cause AIDS. One of the obstacles to treatment of the human immunodeficiency virus (HIV) is its high genetic variability. Major types HIV-1 HIV-1 is the most common and pathogenic strain of the virus. Over 2 million such infections occur annually. Scientists ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibody
An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the pathogen, called an antigen. Each tip of the "Y" of an antibody contains a paratope (analogous to a lock) that is specific for one particular epitope (analogous to a key) on an antigen, allowing these two structures to bind together with precision. Using this binding mechanism, an antibody can ''tag'' a microbe or an infected cell for attack by other parts of the immune system, or can neutralize it directly (for example, by blocking a part of a virus that is essential for its invasion). To allow the immune system to recognize millions of different antigens, the antigen-binding sites at both tips of the antibody come in an equally wide variety. In contrast, the remainder of the antibody is relatively constant. It only occurs in a few varia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitotic Spindles
In cell biology, the spindle apparatus refers to the cytoskeletal structure of eukaryotic cells that forms during cell division to separate sister chromatids between daughter cells. It is referred to as the mitotic spindle during mitosis, a process that produces genetically identical daughter cells, or the meiotic spindle during meiosis, a process that produces gametes with half the number of chromosomes of the parent cell. Besides chromosomes, the spindle apparatus is composed of hundreds of proteins. Microtubules comprise the most abundant components of the machinery. Spindle structure Attachment of microtubules to chromosomes is mediated by kinetochores, which actively monitor spindle formation and prevent premature anaphase onset. Microtubule polymerization and depolymerization dynamic drive chromosome congression. Depolymerization of microtubules generates tension at kinetochores; bipolar attachment of sister kinetochores to microtubules emanating from opposite cell pol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apoptosis
Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, DNA fragmentation, and mRNA decay. The average adult human loses between 50 and 70 billion cells each day due to apoptosis. For an average human child between eight and fourteen years old, approximately twenty to thirty billion cells die per day. In contrast to necrosis, which is a form of traumatic cell death that results from acute cellular injury, apoptosis is a highly regulated and controlled process that confers advantages during an organism's life cycle. For example, the separation of fingers and toes in a developing human embryo occurs because cells between the digits undergo apoptosis. Unlike necrosis, apoptosis produces cell fragments called apoptotic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Survivin
Survivin, also called baculoviral inhibitor of apoptosis repeat-containing 5 or BIRC5, is a protein that, in humans, is encoded by the ''BIRC5'' gene. Survivin is a member of the inhibitor of apoptosis (IAP) family. The survivin protein functions to inhibit caspase activation, thereby leading to negative regulation of apoptosis or programmed cell death. This has been shown by disruption of survivin induction pathways leading to increase in apoptosis and decrease in tumour growth. The survivin protein is expressed highly in most human tumours and fetal tissue, but is completely absent in terminally differentiated cells. These data suggest survivin might provide a new target for cancer therapy that would discriminate between transformed and normal cells. Survivin expression is also highly regulated by the cell cycle and is only expressed in the G2-M phase. It is known that Survivin localizes to the mitotic spindle by interaction with tubulin during mitosis and may play a contributing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherapy may be given with a curative intent (which almost always involves combinations of drugs) or it may aim to prolong life or to reduce symptoms ( palliative chemotherapy). Chemotherapy is one of the major categories of the medical discipline specifically devoted to pharmacotherapy for cancer, which is called ''medical oncology''. The term ''chemotherapy'' has come to connote non-specific usage of intracellular poisons to inhibit mitosis (cell division) or induce DNA damage, which is why inhibition of DNA repair can augment chemotherapy. The connotation of the word chemotherapy excludes more selective agents that block extracellular signals (signal transduction). The development of therapies with specific molecular or genetic targets, wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
