Downregulation of glycogen synthase kinase-3β (GSK-3β) protein expression during neuroblastoma IMR-32 cell differentiation
✍ Scribed by Juan Ramón Muñoz-Montaño; Francisco J. Moreno; Jesús Avila; Javier Díaz-Nido
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 118 KB
- Volume
- 55
- Category
- Article
- ISSN
- 0360-4012
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✦ Synopsis
Glycogen synthase kinase-3 (GSK-3
) is a multifunctional protein kinase that phosphorylates a variety of substrates including the neuronal-specific microtubuleassociated protein tau. Here we report that the downregulation of the GSK-3 protein is an early event in the course of the differentiation of human neuroblastoma IMR-32 cells. This decline in GSK-3 is accompanied by a significant decrease in the phosphorylation state of tau protein. A noteworthy increase in tau protein expression also takes place later during the differentiation of IMR-32 cells. The augmented expression and diminished phosphorylation of tau protein in differentiated IMR-32 cells can be correlated with increments in the assembly of microtubules and in the association of tau with microtubules. These results suggest a contribution of a decrease in GSK-3 to molecular events leading to neuroblastoma cell differentiation. Among these, tau protein dephosphorylation might favor microtubule stabilization within neurites.