Microtubules neural

Other Microtubule Cultured neural Mouse N/A Increased, Miura et al. 

There has been an intensive examination of the biochemical properties of microtubule proteins over the past 15 years, and most of the work has focused on proteins derived from neural systems. For convenience, we will deal with the molecular properties of tubulin first and then collectively consider the so-called microtubule-associated proteins (MAPs). 

This group of three proteins comprises the so-called 10-nm filaments, or intermediate filaments, which are part of neural cytoskeletal systems. Recent evidence suggests that ATP induces the formadon of an associated complex between microtubules and neurofilaments (Runge et al., 1981b), but the role for this associated complex is not established... 

Vimentin is not the only IF type that is moved in this manner. Neural IFs, including both the type III peripherin proteins and type IV neural IF proteins, have also been demonstrated to be moved by molecular motors. In the case of peripherin, particles and squiggles were observed to translocate rapidly within PCI 2 cell bodies, neurites, and growth cones. The movements were bidirectional and dependent on microtubules, kinesin, and cytoplasmic dynein. The authors suggest that peripherin particles are... 

Bernier G, Pool M, Kilcup M, Alfoldi J, De Repentigny Y, et al. 2000. Acf7 (MACF) is an actin and microtubule linker protein whose expression predominates in neural, muscle, and lung development. Dev Dyn 219 216-225. 

Dendrites are the (filamentous) terminal portions of neuron that bind neurotransrrritter chemicals migrating across the synaptic gaps separating neurons. Depending on the type and function of a particular neuron, neurotransmitters may cause or inhibit the transmission of neural impulses. The cell body contains the cell nucleus and a concentration of cellular organelles. The cell body is the site of the normal metabolic reactions that allow the cell to remain viable. Neurotransmitters synthesized within the cell body are transported to the axon terminus by microfilaments and microtubules. 

Intermediate filaments (10 nm) are intermediate in diameter between microtubules (25 nm) and actin filaments (7 nm). Intermediate filaments are classified into five groups cytokeratin, desmin, vimentin, neural, and glial filaments (for review, see Lazarides, 1980). In skeletal muscle, there are both desmin and vimentin filaments. 

The medulloepithelioma looks like carcinoma but occurs in childhood, an unlikely age for carcinoma. The pseudostratified columnar epithelium of medulloepithe-iioma is crowded with cells that resemble those lining the embryonic neural tube. It rests on a type IV collagen basement membrane and fibrous stroma. The basal layer of the epithelium expresses nestin, vimentin, and microtubule-associated protein type 5 immunoreactiv-ity. Focal differentiation and expression of either GFAP, S-100 protein, NSE (Fig. 20.42), NF protein, CK, or EMA immunoreactivity frequently occur. 

Wang, Microtubule-associated protein tau is a substrate of ATP/Mg(2+)-dependent proteasome protease system, J. Neural Transm. 2005, 112, 547-555. 

The MAP called t (tau) is found in neuronal tissue. Phosphorylation of t dissociates i from microtubules, destabilizing the microtubules. Hyperphosphorylation of t has a much more dramatic effect, resulting in the formation of tangles of t-filaments in neural axons, one of the major cellular symptoms of Alzheimer s disease. 

Consistent with the importance of microtubule cytoskeleton in the latter stages of neural differentiation, several microtubule-assodated proteins such as MAP2 and Tau are also up-regulated. MAP2 and MAPIB double knockout mice have fiber tract malformations and retarded neuronal migration. Additionally, primary neuronal cultures derived from these mice display reduced neurite outgrowth (Teng et al., 2001). 

For instance, Kerkis and collaborators detected the presence microtubule-associated proteins (MAPs), such as Lisl and Ndell, as neural markers at early stages of in vitro model for neuronal differentiation from pluripotent stem cells (Kerkis et al., 2011). 

Lis1 and NdeH Microtubule associated proteins involved in neural development... 

Consistent with its importance in the development of the nervous system and its association with the microtubule cytoskeleton, Ndell domain of expression in the developing embryonic neural tube coincides with that of beta III tubulin in the outer mantle zone (Fig. 3). As mentioned in previous sections, the expression of beta III tubulin in post-mitotic cells is associated with neurons that are migrating or emmiting neurites. Thus, the co-localization shown here suggests that Ndell is involved in these processes as well in the chick developing neural tube. 

Microtubule-associated proteins (MAPs) are essential for neuronal differentiation and cell migration during the central nervous system (CNS) development and also in the adult nervous system In particular the distribution and role of lissencephaly (Lisl) and nuclear distribution element-like (Ndell) allows the comp>arison between neural differentiation in stem cells and during embryo development. They are very pwwerful tools not only due to... 

Plausible hypotheses to explain cadmium interference with neural tube closure may be developed on the basis of the importance of cell surface modifications and/or microfllaments and microtubules in the neurulation process, although observations bearing directly on these possibilities have yet to be reported. Virtual restriction of cadmium interference with neural tube closure to the cephalic region, however, would require additional assumptions. This suggests the likelihood that cadmium is affecting some aspect of the closure process that is either peculiar to, or of overriding importance for, closure of the cephalic neural tube. 

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