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Phosphatidylinositol-4-phosphate 5-kinase
Phosphatidylinositol-4-phosphate 5-kinases (PIP5Ks, or PI4P5Ks) are a class of enzymes that phosphorylate phosphatidylinositol 4-phosphate. They perform this reaction on the fifth hydroxyl of the myo-inositol ring to form phosphatidylinositol 4,5-bisphosphate. Function Phosphatidylinositol 4-Phosphate-5 kinase (PI4P5K) or PIP5K or PI5K family regulates diverse cellular processes such as G protein-coupled receptor(GPCR) signaling, vesicle trafficking, chemotaxis and cellular movement. There are at least two types of PIP5K found which includes Type I and Type II. Reinvestigation of the substrate specificity of PI(4)P5Ks, however, revealed that the type II PI(4)P5Ks catalyze phosphorylation of a novel phosphoinositide phosphati- dylinositol 5-phosphate at the D-4 position of the inositol ring, leading to the revised conclusion that the type II enzymes are actually phosphatidylinositol 5-phosphate 4-kinases. Thus, the PI(4)P5K family now comprises just the type I.Other typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enzymes
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecules known as product (chemistry), products. Almost all metabolism, metabolic processes in the cell (biology), cell need enzyme catalysis in order to occur at rates fast enough to sustain life. Metabolic pathways depend upon enzymes to catalyze individual steps. The study of enzymes is called ''enzymology'' and the field of pseudoenzyme, pseudoenzyme analysis recognizes that during evolution, some enzymes have lost the ability to carry out biological catalysis, which is often reflected in their amino acid sequences and unusual 'pseudocatalytic' properties. Enzymes are known to catalyze more than 5,000 biochemical reaction types. Other biocatalysts are Ribozyme, catalytic RNA molecules, called ribozymes. Enzymes' Chemical specificity, specific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphatidylinositol 4,5-bisphosphate
Phosphatidylinositol 4,5-bisphosphate or PtdIns(4,5)''P''2, also known simply as PIP2 or PI(4,5)P2, is a minor phospholipid component of cell membranes. PtdIns(4,5)''P''2 is enriched at the plasma membrane where it is a substrate for a number of important signaling proteins. PIP2 also forms lipid clusters that sort proteins. PIP2 is formed primarily by the type I phosphatidylinositol 4-phosphate 5-kinases from PI(4)P. In metazoans, PIP2 can also be formed by type II phosphatidylinositol 5-phosphate 4-kinases from PI(5)P. The fatty acids of PIP2 are variable in different species and tissues, but the most common fatty acids are stearic in position 1 and arachidonic in 2. Signaling pathways PIP2 is a part of many cellular signaling pathways, including PIP2 cycle, PI3K signalling, and PI5P metabolism. Recently, it has been found in the nucleus with unknown function. Functions Cytoskeleton dynamics near membranes PIP2 regulates the organization, polymerization, and bran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PIP4K2B
Phosphatidylinositol-5-phosphate 4-kinase type-2 beta is an enzyme that in humans is encoded by the ''PIP4K2B'' gene. The protein encoded by this gene catalyzes the phosphorylation of phosphatidylinositol 4-phosphate on the fifth hydroxyl of the myo-inositol ring to form phosphatidylinositol 4,5-bisphosphate. This gene is a member of the phosphatidylinositol-4-phosphate 5-kinase family. The encoded protein sequence does not show similarity to other kinases, but the protein does exhibit kinase activity. Additionally, the encoded protein interacts with p55 TNF receptor. Interactions PIP4K2B has been shown to interact with TNFRSF1A. In addition, PIP4K2B has been shown to interact with PIP4K2A and may modulate the cellular localisation of PIP4K2A. Structure The structure of PIP4K2B has been determined through X-ray crystallography X-ray crystallography is the experimental science determining the atomic and molecular structure of a crystal, in which the crystalline structure ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PIP4K2A
Phosphatidylinositol-5-phosphate 4-kinase type-2 alpha is an enzyme that in humans is encoded by the ''PIP4K2A'' gene. Function Phosphatidylinositol 4,5-bisphosphate, Phosphatidylinositol-4,5-bisphosphate, the precursor to second messengers of the Phosphatidylinositol, phosphoinositide signal transduction pathways, is thought to be involved in the regulation of secretion, Cell growth, cell proliferation, differentiation, and motility. The protein encoded by this gene is one of a family of enzymes capable of catalyzing the phosphorylation of Phosphatidylinositol 4-phosphate, phosphatidylinositol-4-phosphate on the fifth Hydroxy group, hydroxyl of the myo-inositol ring to form phosphatidylinositol-4,5-bisphosphate. The amino acid sequence of this enzyme does not show Homology (biology), homology to other kinases, but the recombinant protein does exhibit kinase activity. This gene is a member of the phosphatidylinositol-4-phosphate 5-kinase family. Clinical significance Through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Nervous System
The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all parts of the bodies of bilaterally symmetric and triploblastic animals—that is, all multicellular animals except sponges and diploblasts. It is a structure composed of nervous tissue positioned along the rostral (nose end) to caudal (tail end) axis of the body and may have an enlarged section at the rostral end which is a brain. Only arthropods, cephalopods and vertebrates have a true brain (precursor structures exist in onychophorans, gastropods and lancelets). The rest of this article exclusively discusses the vertebrate central nervous system, which is radically distinct from all other animals. Overview In vertebrates, the brain and spinal cord are both enclosed in the meninges. The meninges provide a barrier to chemicals dissolv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wnt Signaling Pathway
The Wnt signaling pathways are a group of signal transduction pathways which begin with proteins that pass signals into a cell through cell surface receptors. The name Wnt is a portmanteau created from the names Wingless and Int-1. Wnt signaling pathways use either nearby cell-cell communication (paracrine) or same-cell communication (autocrine). They are highly evolutionarily conserved in animals, which means they are similar across animal species from fruit flies to humans. Three Wnt signaling pathways have been characterized: the canonical Wnt pathway, the noncanonical planar cell polarity pathway, and the noncanonical Wnt/calcium pathway. All three pathways are activated by the binding of a Wnt-protein ligand to a Frizzled family receptor, which passes the biological signal to the Dishevelled protein inside the cell. The canonical Wnt pathway leads to regulation of gene transcription, and is thought to be negatively regulated in part by the SPATS1 gene. The noncanonical plana ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
KIF2A
Kinesin-like protein KIF2A is a protein that in humans is encoded by the ''KIF2A'' 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 ba .... Kinesins, such as KIF2, are microtubule-associated motor proteins. For background information on kinesins, see MIM 148760. upplied by OMIMref name="entrez"> References Further reading * * * * * * * * * External links * {{Cytoskeletal proteins Human proteins Human genes Motor proteins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Growth Cone
A growth cone is a large actin-supported extension of a developing or regenerating neurite seeking its synaptic target. It is the growth cone that drives axon growth. Their existence was originally proposed by Spanish histologist Santiago Ramón y Cajal based upon stationary images he observed under the microscope. He first described the growth cone based on fixed cells as "a concentration of protoplasm of conical form, endowed with amoeboid movements" (Cajal, 1890). Growth cones are situated on the tips of neurites, either dendrites or axons, of the nerve cell. The sensory, motor, integrative, and adaptive functions of growing axons and dendrites are all contained within this specialized structure. Structure The morphology of the growth cone can be easily described by using the hand as an analogy. The fine extensions of the growth cone are pointed filopodia known as microspikes. The filopodia are like the "fingers" of the growth cone; they contain bundles of actin filaments ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axon
An axon (from Greek ἄξων ''áxōn'', axis), or nerve fiber (or nerve fibre: see spelling differences), is a long, slender projection of a nerve cell, or neuron, in vertebrates, that typically conducts electrical impulses known as action potentials away from the nerve cell body. The function of the axon is to transmit information to different neurons, muscles, and glands. In certain sensory neurons (pseudounipolar neurons), such as those for touch and warmth, the axons are called afferent nerve fibers and the electrical impulse travels along these from the periphery to the cell body and from the cell body to the spinal cord along another branch of the same axon. Axon dysfunction can be the cause of many inherited and acquired neurological disorders that affect both the peripheral and central neurons. Nerve fibers are classed into three typesgroup A nerve fibers, group B nerve fibers, and group C nerve fibers. Groups A and B are myelinated, and group C are unmyelinated. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurite Outgrowth Factor
Neurotrophic factors (NTFs) are a family of biomolecules – nearly all of which are peptides or small proteins – that support the growth, survival, and differentiation of both developing and mature neurons. Most NTFs exert their trophic effects on neurons by signaling through tyrosine kinases, usually a receptor tyrosine kinase. In the mature nervous system, they promote neuronal survival, induce synaptic plasticity, and modulate the formation of long-term memories. Neurotrophic factors also promote the initial growth and development of neurons in the central nervous system and peripheral nervous system, and they are capable of regrowing damaged neurons in test tubes and animal models. Some neurotrophic factors are also released by the target tissue in order to guide the growth of developing axons. Most neurotrophic factors belong to one of three families: (1) neurotrophins, (2) glial cell-line derived neurotrophic factor family ligands (GFLs), and (3) neuropo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
