Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The development of highly asymmetrical neurones from undifferentiated neuroblasts involves the extension of processes (axon and dendrites), that depends on the assembly of an inner microtubule scaffolding. Clonal cell lines of neuronal origin, N2A and NIE-115 neuroblastoma cells, have been chosen as model systems to study the modifications of microtubule protein which accompany the outgrowth of axon-like processes (neurites). Neuroblastoma cells grow as proliferating and undifferentiated cells in standard culture medium but can be considered as committed neuronal precursors. Thus, they are characterized by a high content of tubulin, including the minor neuronal-specific beta 3 isoform, and of MAPs including MAP1B and tau-like proteins. Serum withdrawal from the culture medium results in the extension of axon-like processes which is paralleled by a net increase in the amount of assembled tubulin. However, there is not any increase in the total amount of either tubulin or major MAPs which suggests an involvement of other regulatory factors in the promotion of microtubule assembly. Of relevance in this respect is the fact that beta 3-tubulin, MAP1B, and tau-like proteins become phosphorylated during neurite extension. A casein kinase II-like enzyme may be involved in some of these phosphorylation events. This enzyme is primarily localized to the nuclei in undifferentiated neuroblastoma cells, whereas a wider distribution of the enzyme between the nucleus and the cytoplasm is found in differentiating neuroblastoma cells. It thus appears plausible that a modified sorting of casein kinase II into the nucleus and the cytoplasm may be involved in the triggering of the phosphorylation of microtubule proteins during neuroblastoma cell differentiation.
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PMID:Microtubule protein phosphorylation in neuroblastoma cells and neurite growth. 182 7

1. Although microtubule-associated protein (MAP) 1B and its phosphorylation have been suggested to be important for synapse formation among cortical neurons, the localization of MAP1B in synapses has not yet been confirmed. In this report, we examine the localization of MAP1B in synaptic regions. 2. The localization of MAP1B was observed by immunohistochemical and electron microscopic techniques using specific antibodies against MAP1B. 3. MAP1B immunoreactivities were widely distributed in the cerebral cortex and were observed in the postsynaptic area but not in presynaptic terminals. 4. These synapses were classified as the asymmetrical type. 5. Only some synapses exhibited MAP1B immunoreactivities. MAP1B-immunopositive synapses accounted for about half of the total synapses. 6. Such a localization suggests MAP1B's important roles in synaptic functions.
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PMID:Localization of microtubule-associated protein (MAP) 1B in the postsynaptic densities of the rat cerebral cortex. 1496 76

The cytoskeleton plays a key role in maintaining the highly asymmetrical shape and structural polarity of neurons that are essential for neuronal physiology. Cytoskeletal reorganization plays a key role in neuritogenesis. In neurodegenerative diseases, the cytoskeleton is abnormally assembled and impairment of neurotransmission occurs. In Alzheimer's disease, abundant amyloid plaques and neurofibrillary tangles constitute the two major neuropathologic alterations present in the brain. Neurofibrillary tangles are formed of paired helical filaments consisting nearly entirely of the microtubule-associated protein tau. Under normal conditions tau binds to microtubules, stabilizing neuron structure and integrity. Hyperphosphorylation of tau is assumed to be the cause of formation of paired helical filaments. Another example of cytoskeletal abnormalities present in neurodegenerative diseases are the Lewy bodies considered as cytopathologic markers of Parkinson's disease. Lewy bodies are constituted of tubulin, MAP1, and MAP2. Neuronal shape, loss of dendrites and spines, as well as irregular distribution of neuronal elongations occur in specific brain areas of schizophrenic patients. Increase in non-phosphorylated MAP2 and MAP1B at hippocampus has been suggested as responsible for somatodendritic and cytoarchitectural abnormalities found in schizophrenia. In addition, neurofibrillary tangles are more frequent among schizophrenic patients who received pharmacologic antipsychotic treatment. Cumulative evidence suggests that neurodegenerative diseases and psychiatric illnesses are associated with cytoskeletal alterations in neurons that, in turn, loose synaptic connectivity and the ability to transmit incoming axonal information to the somatodendritic domain. We will review evidence supporting that the neuronal cytoskeleton is disrupted in neurodegenerative and some psychiatric diseases, and therefore could be a target for drug therapy. In addition, current data indicating that melatonin, a hormone secreted by the pineal gland, promotes neuritogenesis through cytoskeletal rearrangements and in addition to the potential therapeutic use of melatonin in neurodegenerative diseases will be discussed.
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PMID:The neuronal cytoskeleton as a potential therapeutical target in neurodegenerative diseases and schizophrenia. 1558 21