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DNM1L
Dynamin-1-like protein is a GTPase that regulates mitochondrial fission. In humans, dynamin-1-like protein, which is typically referred to as dynamin-related protein 1 (Drp1), is encoded by the ''DNM1L'' gene and is part of the dynamin superfamily (DSP) family of proteins. Structure Drp1, which is a member of the dynamin superfamily of proteins, consists of a GTPase and GTPase effector domain that are separated from each other by a helical segment of amino acids. There are 3 mouse and 6 human isoforms of Drp1, including a brain-specific variant. Drp1 exists as homooligomers and its function relies on its oligomerization ability. Function Mitochondria routinely undergo fission and fusion events that maintain a dynamic reticular network. Drp1 is a fundamental component of mitochondrial fission. Indeed, Drp1 deficient neurons have large, strongly interconnected mitochondria due to dysfunctional fission machinery. Fission helps facilitate mitophagy, which is the breakdown and r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FIS1
Mitochondrial fission 1 protein (FIS1) is a protein that in humans is encoded by the ''FIS1'' gene on chromosome 7. This protein is a component of a mitochondrial complex, the ARCosome, that promotes mitochondrial fission. Its role in mitochondrial fission thus implicates it in the regulation of mitochondrial morphology, the cell cycle, and apoptosis. By extension, the protein is involved in associated diseases, including neurodegenerative diseases and cancers. Structure The protein encoded by this gene is a 16 kDa integral protein situated in the outer mitochondrial membrane (OMM). It is composed of a transmembrane domain at the C-terminal and a cytosolic domain at the N-terminal. The transmembrane domain anchors FIS1 in the OMM, though it has been observed to target different cellular compartments, such as the peroxisome, depending on its hydrophobicity, charge, and length. Meanwhile, the cytosolic domain contains a bundle of six helices, four of which contain two tandem tetr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrial Fission
Mitochondrial fission is the process where mitochondria divide or segregate into two separate mitochondrial organelles. Mitochondrial fission is counteracted by the process of mitochondrial fusion, whereby two separate mitochondria can fuse together to form a large one. Mitochondrial fusion in turn can result in elongated mitochondrial networks. Both mitochondrial fission and fusion are balanced in the cell, and mutations interfering with either processes are associated with a variety of diseases. Mitochondria can divide by prokaryotic binary fission and since they require mitochondrial DNA for their function, fission is coordinated with DNA replication. Some of the proteins that are involved in mitochondrial fission have been identified and some of them are associated with mitochondrial diseases. Mitochondrial fission has significant implications in stress response and apoptosis. Mechanism FtsZ Localization The FtsZ protein (a homologue to eukaryotic tubulin), found in many b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GSK3B
Glycogen synthase kinase-3 beta, (GSK-3 beta), is an enzyme that in humans is encoded by the ''GSK3B'' gene. In mice, the enzyme is encoded by the Gsk3b gene. Abnormal regulation and expression of GSK-3 beta is associated with an increased susceptibility towards bipolar disorder. Function Glycogen synthase kinase-3 (GSK-3) is a proline-directed serine-threonine kinase that was initially identified as a phosphorylating and an inactivating agent of glycogen synthase. Two isoforms, alpha ( GSK3A) and beta, show a high degree of amino acid homology. GSK3B is involved in energy metabolism, neuronal cell development, and body pattern formation. It might be a new therapeutic target for ischemic stroke. Disease relevance Homozygous disruption of the Gsk3b locus in mice results in embryonic lethality during mid-gestation. This lethality phenotype could be rescued by inhibition of tumor necrosis factor. Two SNPs at this gene, rs334558 (-50T/C) and rs3755557 (-1727A/T), are associ ... [...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 recepto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alzheimer’s
Alzheimer's disease (AD) is a neurodegenerative disease that usually starts slowly and progressively worsens. It is the cause of 60–70% of cases of dementia. The most common early symptom is difficulty in remembering recent events. As the disease advances, symptoms can include problems with language, disorientation (including easily getting lost), mood swings, loss of motivation, self-neglect, and behavioral issues. As a person's condition declines, they often withdraw from family and society. Gradually, bodily functions are lost, ultimately leading to death. Although the speed of progression can vary, the typical life expectancy following diagnosis is three to nine years. The cause of Alzheimer's disease is poorly understood. There are many environmental and genetic risk factors associated with its development. The strongest genetic risk factor is from an allele of APOE. Other risk factors include a history of head injury, clinical depression, and high blood pressure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ubiquitination
Ubiquitin is a small (8.6 kDa) regulatory protein found in most tissues of eukaryotic organisms, i.e., it is found ''ubiquitously''. It was discovered in 1975 by Gideon Goldstein and further characterized throughout the late 1970s and 1980s. Four genes in the human genome code for ubiquitin: UBB, UBC, UBA52 and RPS27A. The addition of ubiquitin to a substrate protein is called ubiquitylation (or, alternatively, ubiquitination or ubiquitinylation). Ubiquitylation affects proteins in many ways: it can mark them for degradation via the proteasome, alter their cellular location, affect their activity, and promote or prevent protein interactions. Ubiquitylation involves three main steps: activation, conjugation, and ligation, performed by ubiquitin-activating enzymes (E1s), ubiquitin-conjugating enzymes (E2s), and ubiquitin ligases (E3s), respectively. The result of this sequential cascade is to bind ubiquitin to lysine residues on the protein substrate via an isopeptide b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sumoylation
In molecular biology, SUMO (Small Ubiquitin-like Modifier) proteins are a family of small proteins that are covalently attached to and detached from other proteins in cells to modify their function. This process is called SUMOylation (sometimes written sumoylation). SUMOylation is a post-translational modification involved in various cellular processes, such as nuclear- cytosolic transport, transcriptional regulation, apoptosis, protein stability, response to stress, and progression through the cell cycle. SUMO proteins are similar to ubiquitin and are considered members of the ubiquitin-like protein family. SUMOylation is directed by an enzymatic cascade analogous to that involved in ubiquitination. In contrast to ubiquitin, SUMO is not used to tag proteins for degradation. Mature SUMO is produced when the last four amino acids of the C-terminus have been cleaved off to allow formation of an isopeptide bond between the C-terminal glycine residue of SUMO and an acceptor lys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CaMKII
/calmodulin-dependent protein kinase II (CaM kinase II or CaMKII) is a serine/threonine-specific protein kinase that is regulated by the /calmodulin complex. CaMKII is involved in many signaling cascades and is thought to be an important mediator of learning and memory. CaMKII is also necessary for homeostasis and reuptake in cardiomyocytes, chloride transport in epithelia, positive T-cell selection, and CD8 T-cell activation. Misregulation of CaMKII is linked to Alzheimer's disease, Angelman syndrome, and heart arrhythmia. Types There are two types of CaM kinase: * Specialized CaM kinases, such as the myosin light chain kinase that phosphorylates myosin, causing smooth muscles to contract * Multifunctional CaM kinases, also collectively called ''CaM kinase II'', which play a role in neurotransmitter secretion, transcription factor regulation, and glycogen metabolism. Structure, function, and autoregulation CaMKII accounts for 1–2% of all proteins in the brain, and h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorylation
In chemistry, phosphorylation is the attachment of a phosphate group to a molecule or an ion. This process and its inverse, dephosphorylation, are common in biology and could be driven by natural selection. Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. Protein phosphorylation often activates (or deactivates) many enzymes. Glucose Phosphorylation of sugars is often the first stage in their catabolism. Phosphorylation allows cells to accumulate sugars because the phosphate group prevents the molecules from diffusing back across their transporter. Phosphorylation of glucose is a key reaction in sugar metabolism. The chemical equation for the conversion of D-glucose to D-glucose-6-phosphate in the first step of glycolysis is given by :D-glucose + ATP → D-glucose-6-phosphate + ADP : ΔG° = −16.7 kJ/mol (° indicates measurement at standard condition) Hepatic cells are freely permeable to glucose, and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Post-translational Modifications
Post-translational modification (PTM) is the covalent and generally enzymatic modification of proteins following protein biosynthesis. This process occurs in the endoplasmic reticulum and the golgi apparatus. Proteins are synthesized by ribosomes translating mRNA into polypeptide chains, which may then undergo PTM to form the mature protein product. PTMs are important components in cell signaling, as for example when prohormones are converted to hormones. Post-translational modifications can occur on the amino acid side chains or at the protein's C- or N- termini. They can extend the chemical repertoire of the 20 standard amino acids by modifying an existing functional group or introducing a new one such as phosphate. Phosphorylation is a highly effective mechanism for regulating the activity of enzymes and is the most common post-translational modification. Many eukaryotic and prokaryotic proteins also have carbohydrate molecules attached to them in a process called glycos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
