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Atlastin
Atlastins (ATLs) are a class of endoplasmic reticulum (ER) GTPases. Invertebrates have a single ATL, while vertebrates possess three ATL proteins (ATL1-3) that are differentially expressed. ATL1 is the predominant paralog of the central nervous system, whereas ATL2 and ATL3 are mainly expressed in tissues outside of the CNS. Loss of all ATLs in mammalian cells dramatically impacts ER structure, including a reduction in tubule three-way junctions. Function and Regulation ATLs maintain the ER tubular network via homotypic fusion. ATLs have a conserved domain structure consisting of a globular G domain, a three-helix bundle, two transmembrane domains, and an amphipathic helix. The ATL fusion cycle consists of two ATL monomers in opposing membranes binding GTP, which induces trans G domain dimerization and a crossing over of the three-helix bundle. Crossover and subsequent insertion of the amphipathic helix into the lipid bilayer triggers lipids to mix for fusion. Lastly, GTP is hyd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hereditary Spastic Paraplegia
Hereditary spastic paraplegia (HSP) is a group of inherited diseases whose main feature is a progressive gait disorder. The disease presents with progressive stiffness (spasticity) and contraction in the lower limbs. HSP is also known as hereditary spastic paraparesis, familial spastic paraplegia, French settlement disease, Strumpell disease, or Strumpell-Lorrain disease. The symptoms are a result of dysfunction of long axons in the spinal cord. The affected cells are the primary motor neurons; therefore, the disease is an upper motor neuron disease. HSP is not a form of cerebral palsy even though it physically may appear and behave much the same as spastic diplegia. The origin of HSP is different from cerebral palsy. Despite this, some of the same anti-spasticity medications used in spastic cerebral palsy are sometimes used to treat HSP symptoms. HSP is caused by defects in transport of proteins, structural proteins, cell-maintaining proteins, lipids, and other substances th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endoplasmic Reticulum
The endoplasmic reticulum (ER) is, in essence, the transportation system of the eukaryotic cell, and has many other important functions such as protein folding. It is a type of organelle made up of two subunits – rough endoplasmic reticulum (RER), and smooth endoplasmic reticulum (SER). The endoplasmic reticulum is found in most eukaryotic cells and forms an interconnected network of flattened, membrane-enclosed sacs known as cisternae (in the RER), and tubular structures in the SER. The membranes of the ER are continuous with the outer nuclear membrane. The endoplasmic reticulum is not found in red blood cells, or spermatozoa. The two types of ER share many of the same proteins and engage in certain common activities such as the synthesis of certain lipids and cholesterol. Different types of cells contain different ratios of the two types of ER depending on the activities of the cell. RER is found mainly toward the nucleus of cell and SER towards the cell membrane or pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GTPase
GTPases are a large family of hydrolase enzymes that bind to the nucleotide guanosine triphosphate (GTP) and hydrolyze it to guanosine diphosphate (GDP). The GTP binding and hydrolysis takes place in the highly conserved P-loop "G domain", a protein domain common to many GTPases. Functions GTPases function as molecular switches or timers in many fundamental cellular processes. Examples of these roles include: * Signal transduction in response to activation of cell surface receptors, including transmembrane receptors such as those mediating taste, smell and vision. * Protein biosynthesis (a.k.a. translation) at the ribosome. * Regulation of cell differentiation, proliferation, division and movement. * Translocation of proteins through membranes. * Transport of vesicles within the cell, and vesicle-mediated secretion and uptake, through GTPase control of vesicle coat assembly. GTPases are active when bound to GTP and inactive when bound to GDP. In the generalized r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spastin
The human gene SPAST codes for the microtubule-severing protein of the same name, commonly known as spastin. This gene encodes a member of the AAA (ATPases associated with a variety of cellular activities) protein family. Members of this protein family share an ATPase domain and have roles in diverse cellular processes including membrane trafficking, intracellular motility, organelle biogenesis, protein folding, and proteolysis. The encoded ATPase may be involved in the assembly or function of nuclear protein complexes. Two transcript variants encoding distinct isoforms have been identified for this gene. Other alternative splice variants have been described but their full length sequences have not been determined. Mutations associated with this gene cause the most frequent form of autosomal dominant spastic paraplegia 4. See also Spastic paraplegia Hereditary spastic paraplegia (HSP) is a group of inherited diseases whose main feature is a progressive gait disorder. The disease ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
REEP1
Receptor expression-enhancing protein 1 is a protein that in humans is encoded by the ''REEP1'' 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 b .... References Further reading * * * * * * * {{gene-2-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
