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L1CAM Structure
L1, also known as L1CAM, is a transmembrane protein member of the L1 family, L1 protein family, encoded by the ''L1CAM'' gene. This protein, of 200 to 220 kDa, is a neuronal cell adhesion molecule with a strong implication in cell migration, adhesion, neurite outgrowth, myelination and neuronal differentiation. It also plays a key role in treatment-resistant cancers due to its function. It was first identified in 1984 by M. Schachner who found the protein in post-mitotic mice neurons. Mutations in the L1 protein are the cause of L1 syndrome, sometimes known by the acronym CRASH L1 syndrome, (corpus callosum hypoplasia, retardation, aphasia, spastic paraplegia and hydrocephalus). Tissue and cellular distribution L1 protein is located all over the nervous system on the surface of neurons. It is placed along the cellular membrane so that one end of the protein remains inside the nerve cell while the other end stays on the outer surface of the neurone. This position allows the pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transmembrane Protein
A transmembrane protein is a type of integral membrane protein that spans the entirety of the cell membrane. Many transmembrane proteins function as gateways to permit the transport of specific substances across the membrane. They frequently undergo significant conformational changes to move a substance through the membrane. They are usually highly hydrophobic and aggregate and precipitate in water. They require detergents or nonpolar solvents for extraction, although some of them ( beta-barrels) can be also extracted using denaturing agents. The peptide sequence that spans the membrane, or the transmembrane segment, is largely hydrophobic and can be visualized using the hydropathy plot. Depending on the number of transmembrane segments, transmembrane proteins can be classified as single-pass membrane proteins, or as multipass membrane proteins. Some other integral membrane proteins are called monotopic, meaning that they are also permanently attached to the membrane, b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glycoprotein
Glycoproteins are proteins which contain oligosaccharide (sugar) chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. Secreted extracellular proteins are often glycosylated. In proteins that have segments extending extracellularly, the extracellular segments are also often glycosylated. Glycoproteins are also often important integral membrane proteins, where they play a role in cell–cell interactions. It is important to distinguish endoplasmic reticulum-based glycosylation of the secretory system from reversible cytosolic-nuclear glycosylation. Glycoproteins of the cytosol and nucleus can be modified through the reversible addition of a single GlcNAc residue that is considered reciprocal to phosphorylation and the functions of these are likely to be an additional regulatory mechanism that controls phosphorylation-based signalling. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agenesis Of The Corpus Callosum
Agenesis of the corpus callosum (ACC) is a rare birth defect in which there is a complete or partial absence of the corpus callosum. It occurs when the development of the corpus callosum, the band of white matter connecting the two hemispheres in the brain, in the embryo is disrupted. The result of this is that the fibers that would otherwise form the corpus callosum are instead longitudinally oriented along the ipsilateral ventricular wall and form structures called Probst bundles. In addition to agenesis, other degrees of callosal defects exist, including hypoplasia (underdevelopment or thinness), hypogenesis (partial agenesis) or dysgenesis (malformation). ACC is found in many syndromes and can often present alongside hypoplasia of the cerebellar vermis. When this is the case, there can also be an enlarged fourth ventricle or hydrocephalus; this is called Dandy–Walker malformation. Signs and symptoms Laboratory research has demonstrated that individuals with ACC have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MASA Syndrome
MASA syndrome is a rare X-linked recessive neurological disorder on the L1 disorder spectrum belonging in the group of hereditary spastic paraplegias a paraplegia known to increase stiffness spasticity in the lower limbs. This syndrome also has two other names, CRASH syndrome and Gareis-Mason syndrome. Signs and symptoms The acronym "MASA" stands for the four main signs and symptoms associated with the syndrome: (1) mental retardation (mild to moderate intellectual disability), (2) aphasia (delayed onset of speech), (3) shuffling gait, and (4) adducted thumbs characterized by cleft palate, microcephaly, and dysmyelination. Affected males may also have a variable dilatation (widening) of the third heart ventricle. MASA has five other factors including hydrocephalus. The build-up is often caused by an obstruction that prevents proper fluid drainage. Spasticity of the lower limbs, causing the muscles to stiffen or tighten, preventing normal fluid movement. Aphasia, which is when s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrocephalus
Hydrocephalus is a condition in which cerebrospinal fluid (CSF) builds up within the brain, which can cause pressure to increase in the skull. Symptoms may vary according to age. Headaches and double vision are common. Elderly adults with normal pressure hydrocephalus (NPH) may have poor balance, difficulty controlling urination, or mental impairment. In babies, there may be a rapid increase in head size. Other symptoms may include vomiting, sleepiness, seizures, and downward pointing of the eyes. Hydrocephalus can occur due to birth defects (primary) or can develop later in life (secondary). Hydrocephalus can be classified via mechanism into communicating, noncommunicating, ''ex vacuo'', and normal pressure hydrocephalus. Diagnosis is made by physical examination and medical imaging, such as a CT scan. Hydrocephalus is typically treated through surgery. One option is the placement of a shunt system. A procedure called an endoscopic third ventriculostomy has gained ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nervous System
In biology, the nervous system is the complex system, highly complex part of an animal that coordinates its behavior, actions and sense, sensory information by transmitting action potential, signals to and from different parts of its body. The nervous system detects environmental changes that impact the body, then works in tandem with the endocrine system to respond to such events. Nervous tissue first arose in Ediacara biota, wormlike organisms about 550 to 600 million years ago. In Vertebrate, vertebrates, it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers, or axons, that connect the CNS to every other part of the body. Nerves that transmit signals from the brain are called motor nerves (efferent), while those nerves that transmit information from the body to the CNS are called sensory nerves (aff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signal Transduction
Signal transduction is the process by which a chemical or physical signal is transmitted through a cell as a biochemical cascade, series of molecular events. Proteins responsible for detecting stimuli are generally termed receptor (biology), receptors, although in some cases the term sensor is used. The changes elicited by ligand (biochemistry), ligand binding (or signal sensing) in a receptor give rise to a biochemical cascade, which is a chain of biochemical events known as a Cell signaling#Signaling pathways, signaling pathway. When signaling pathways interact with one another they form networks, which allow cellular responses to be coordinated, often by combinatorial signaling events. At the molecular level, such responses include changes in the transcription (biology), transcription or translation (biology), translation of genes, and post-translational modification, post-translational and conformational changes in proteins, as well as changes in their location. These molecula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synaptic Plasticity
In neuroscience, synaptic plasticity is the ability of synapses to Chemical synapse#Synaptic strength, strengthen or weaken over time, in response to increases or decreases in their activity. Since memory, memories are postulated to be represented by vastly interconnected neural circuits in the brain, synaptic plasticity is one of the important neurochemical foundations of learning and memory (''see Hebbian theory''). Plastic change often results from the alteration of the number of neurotransmitter receptors located on a synapse. There are several underlying mechanisms that cooperate to achieve synaptic plasticity, including changes in the quantity of neurotransmitters released into a synapse and changes in how effectively cells respond to those neurotransmitters. Synaptic plasticity in both Excitatory synapse, excitatory and Inhibitory synapse, inhibitory synapses has been found to be dependent upon postsynaptic calcium release. Historical discoveries In 1973, Terje Lømo and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neural Development
The development of the nervous system, or neural development (neurodevelopment), refers to the processes that generate, shape, and reshape the nervous system of animals, from the earliest stages of embryonic development to adulthood. The field of neural development draws on both neuroscience and developmental biology to describe and provide insight into the cellular and molecular mechanisms by which complex nervous systems develop, from nematodes and Drosophila melanogaster, fruit flies to mammals. Defects in neural development can lead to malformations such as holoprosencephaly, and a wide variety of neurological disorders including paresis, limb paresis and paralysis, balance and vision disorders, and seizures, and in humans other disorders such as Rett syndrome, Down syndrome and intellectual disability. Vertebrate brain development The vertebrate central nervous system (CNS) is derived from the ectoderm—the outermost germ layer of the embryo. A part of the dorsal ect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Adhesion
Cell adhesion is the process by which cells interact and attach to neighbouring cells through specialised molecules of the cell surface. This process can occur either through direct contact between cell surfaces such as Cell_junction, cell junctions or indirect interaction, where cells attach to surrounding extracellular matrix (ECM), a gel-like structure containing molecules released by cells into spaces between them. Cells adhesion occurs from the interactions between cell adhesion molecules, cell-adhesion molecules (CAMs), transmembrane proteins located on the cell surface. Cell adhesion links cells in different ways and can be involved in signal transduction for cells to detect and respond to changes in the surroundings. Other cellular processes regulated by cell adhesion include cell migration and tissue development in multicellular organisms. Alterations in cell adhesion can disrupt important cellular processes and lead to a variety of diseases, including cancer and arthrit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nervous System
In biology, the nervous system is the complex system, highly complex part of an animal that coordinates its behavior, actions and sense, sensory information by transmitting action potential, signals to and from different parts of its body. The nervous system detects environmental changes that impact the body, then works in tandem with the endocrine system to respond to such events. Nervous tissue first arose in Ediacara biota, wormlike organisms about 550 to 600 million years ago. In Vertebrate, vertebrates, it consists of two main parts, the central nervous system (CNS) and the peripheral nervous system (PNS). The CNS consists of the brain and spinal cord. The PNS consists mainly of nerves, which are enclosed bundles of the long fibers, or axons, that connect the CNS to every other part of the body. Nerves that transmit signals from the brain are called motor nerves (efferent), while those nerves that transmit information from the body to the CNS are called sensory nerves (aff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immunoglobulin Domain
The immunoglobulin domain, also known as the immunoglobulin fold, is a type of protein domain that consists of a 2-layer sandwich of 7-9 antiparallel β-strands arranged in two β-sheets with a Greek key topology, consisting of about 125 amino acids. The backbone switches repeatedly between the two β-sheets. Typically, the pattern is (N-terminal β-hairpin in sheet 1)-(β-hairpin in sheet 2)-(β-strand in sheet 1)-(C-terminal β-hairpin in sheet 2). The cross-overs between sheets form an "X", so that the N- and C-terminal hairpins are facing each other. Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin, and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein–protein and protein–ligand interactions. Examples Human genes encoding proteins containing the immunoglobulin domain include: * A1BG * ACAM * ADAMTSL1 * ADAMTSL3 * AGE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
