Microtubule-associated expression

Gleeson JG, Lin PT, Flanagan LA, Walsh CA 1999 Doublecortin is a microtubule-associated protein and is expressed widely by migrating neurons. Neuron 23 257—271 Goldstein B, Hird SN 1996 Specification of the anteroposterior axis in Caenorhabditit elegant. Development 122 1467-1474... 

ATP 4- protein r <1, 2, 4, 5> (<5> microtubule-associated protein, enzyme can also phosphorylate human tau [1] <1> phosphorylates r and forms paired helical filament epitopes, r/Kl, K2, K3 and t/4 repeat [6] <2> enzyme can also phosphorylate bovine tau [4] <2> phosphorylates r protein into Alzheimer disease-like forms, resulting in neuronal death [7] <2> 6 isoforms of human r expressed in adult human brain [12] <2> when a / -mediated aggregated r is used as a substrate for TPKII, an 8fold increase in the rate of TPKII-mediated r phosphorylation is observed... 

Francis F, Koulakoff A, Boucher D, Chafey P, Schaar B, Vinet MC, Friocourt G, McDonnell N, Reiner O, Kahn A, McConnell SK, Berwald-Netter Y, Denoulet P, Chelly J (1999) Dou-blecortin is a developmentally regulated, microtubule-associated protein expressed in migrating and differentiating neurons. Neuron 23 247-256... 

Couchie D, Legay F, Guilleminot J, Lebeugy F, Brion JP, Nunez J (1990) Expression of Tau protein and Tau mRNA in the cerebellum during axontil outgrowth. Exp Brain Res 82 589-596 Crowther T, Goedert M, Wischik CM (1989) The repeat region of microtubule-associated protein tau forms part of the core of the paired helical fileunent of Alzheimer s disease. Ann Med 21 127-132... 

Avila J, Dominguez J, Diaz-Nido J (1994) Reguladon of microtubule dynamics by microtubule-associated protein expression and phosphoryladon during neui onal development. Int J Dev Biol 38 13-25. 

Burgoyne RD, Cumming R (1984) Ontogeny of microtubule-associated protein 2 in rat cerebellum Differential expression of the doublet polypeptides. Neuroscience 11 156-167. 

Dotti CG, Banker GA, Binder LI (1987) The expression and distribution of the microtubule-associated proteins tau and microtubule-associated protein 2 in hippocampal neurons in the rat in situ and in cell culture. Neuroscience 23 121-130... 

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. 

Of the 12,000 combined genes and ESTs represented on the array, only 10 changed in expression level by a factor of threefold or more, and all were upregulated. In the cortex, mRNAs for neuronal tyrosine/threonine phosphatase 1 and microtubule-associated tau were significantly enhanced. These proteins are both associated with formation/breakdown of intracellular neurofibrillary tangles, a hallmark lesion of Alzheimer s disease. Hyperphosphorylated tau has been found to be the major protein of these neurofibrillary tangles, possibly because of an imbalance in tau kinase and phosphatase activities in the affected neurons [27]. Hyperphosphorylated tau isolated from brains of patients with Alzheimer s disease has been shown to be efficiently dephosphorylated in vitro by protein phosphatases 1, 2A, and 2B. Additionally, selective inhibition of protein phosphatase 2A by okadaic acid in metabolically competent rat brain slices has been shown to induce a hyperphosphorylation and accumulation of tau like that in Alzheimer s disease [28]. Thus, upregulation of neuronal phosphatase 1 by EGb 761 could play a neuroprotective role in the brain. 

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