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Dishevelled-1 regulates microtubule stability: a new function mediated by glycogen synthase kinase-3beta.

Krylova O, Messenger MJ, Salinas PC - J. Cell Biol. (2000)

Bottom Line: The microtubule stabilizing function of DVL-1 is mimicked by lithium-mediated inhibition of glycogen synthase kinase-3beta (GSK-3beta) and blocked by expression of GSK-3beta.These findings suggest that DVL-1, through GSK-3beta, can regulate microtubule dynamics.This new function of DVL-1 in controlling microtubule stability may have important implications for Dishevelled proteins in regulating cell polarity.

View Article: PubMed Central - PubMed

Affiliation: The Randall Institute, King's College London, London, United Kingdom.

ABSTRACT
Dishevelled has been implicated in the regulation of cell fate decisions, cell polarity, and neuronal function. However, the mechanism of Dishevelled action remains poorly understood. Here we examine the cellular localization and function of the mouse Dishevelled protein, DVL-1. Endogenous DVL-1 colocalizes with axonal microtubules and sediments with brain microtubules. Expression of DVL-1 protects stable microtubules from depolymerization by nocodazole in both dividing cells and differentiated neuroblastoma cells. Deletion analyses reveal that the PDZ domain, but not the DEP domain, of DVL-1 is required for microtubule stabilization. The microtubule stabilizing function of DVL-1 is mimicked by lithium-mediated inhibition of glycogen synthase kinase-3beta (GSK-3beta) and blocked by expression of GSK-3beta. These findings suggest that DVL-1, through GSK-3beta, can regulate microtubule dynamics. This new function of DVL-1 in controlling microtubule stability may have important implications for Dishevelled proteins in regulating cell polarity.

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DVL-1 stabilizes axonal microtubules. (A–C) Differentiated NB2a cells expressing DVL-HA have higher levels of acetylated MTs (arrows) than untransfected neighboring cells (arrowhead). (D–F) Neurons expressing DVL-HA have acetylated MTs after nocodazole treatment (arrow), whereas untransfected cells have no acetylated MTs (asterisk). Bar, 25 μM.
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Figure 8: DVL-1 stabilizes axonal microtubules. (A–C) Differentiated NB2a cells expressing DVL-HA have higher levels of acetylated MTs (arrows) than untransfected neighboring cells (arrowhead). (D–F) Neurons expressing DVL-HA have acetylated MTs after nocodazole treatment (arrow), whereas untransfected cells have no acetylated MTs (asterisk). Bar, 25 μM.

Mentions: DVL-1 colocalizes with axonal MTs in maturing neurons (Fig. 3). To test whether DVL-1 also regulates the stability of axonal MTs, we examined the effect of expression of DVL-HA in differentiated NB2a neuroblastoma cells. Untransfected and GFP-expressing NB2a cells have bundles of acetylated MTs along the axon (Fig. 8B and Fig. C, and data not shown). In contrast, expression of DVL-HA increases the level of acetylated MTs in NB2a neurons (Fig. 8, A–C). Treatment with nocodazole results in the loss of acetylated MTs and retraction of axons in untransfected NB2a cells (Fig. 8E and Fig. F), whereas DVL-HA protects stable MTs from nocodazole treatment (Fig. 8, D–F), as observed in COS cells (Fig. 5, G–I). DVL-HA–expressing cells do not retract their axons in the presence of nocodazole (Fig. 8, D–F). Thus, DVL-1 increases the level of acetylated MTs and stabilizes axonal MTs against the depolymerizing effect of nocodazole. Like in COS cells, lithium treatment also results in increased MT stability (data not shown). These findings suggest that neuronal DVL-1 regulates, through GSK-3β, MT stability in developing axons.


Dishevelled-1 regulates microtubule stability: a new function mediated by glycogen synthase kinase-3beta.

Krylova O, Messenger MJ, Salinas PC - J. Cell Biol. (2000)

DVL-1 stabilizes axonal microtubules. (A–C) Differentiated NB2a cells expressing DVL-HA have higher levels of acetylated MTs (arrows) than untransfected neighboring cells (arrowhead). (D–F) Neurons expressing DVL-HA have acetylated MTs after nocodazole treatment (arrow), whereas untransfected cells have no acetylated MTs (asterisk). Bar, 25 μM.
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Related In: Results  -  Collection

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Figure 8: DVL-1 stabilizes axonal microtubules. (A–C) Differentiated NB2a cells expressing DVL-HA have higher levels of acetylated MTs (arrows) than untransfected neighboring cells (arrowhead). (D–F) Neurons expressing DVL-HA have acetylated MTs after nocodazole treatment (arrow), whereas untransfected cells have no acetylated MTs (asterisk). Bar, 25 μM.
Mentions: DVL-1 colocalizes with axonal MTs in maturing neurons (Fig. 3). To test whether DVL-1 also regulates the stability of axonal MTs, we examined the effect of expression of DVL-HA in differentiated NB2a neuroblastoma cells. Untransfected and GFP-expressing NB2a cells have bundles of acetylated MTs along the axon (Fig. 8B and Fig. C, and data not shown). In contrast, expression of DVL-HA increases the level of acetylated MTs in NB2a neurons (Fig. 8, A–C). Treatment with nocodazole results in the loss of acetylated MTs and retraction of axons in untransfected NB2a cells (Fig. 8E and Fig. F), whereas DVL-HA protects stable MTs from nocodazole treatment (Fig. 8, D–F), as observed in COS cells (Fig. 5, G–I). DVL-HA–expressing cells do not retract their axons in the presence of nocodazole (Fig. 8, D–F). Thus, DVL-1 increases the level of acetylated MTs and stabilizes axonal MTs against the depolymerizing effect of nocodazole. Like in COS cells, lithium treatment also results in increased MT stability (data not shown). These findings suggest that neuronal DVL-1 regulates, through GSK-3β, MT stability in developing axons.

Bottom Line: The microtubule stabilizing function of DVL-1 is mimicked by lithium-mediated inhibition of glycogen synthase kinase-3beta (GSK-3beta) and blocked by expression of GSK-3beta.These findings suggest that DVL-1, through GSK-3beta, can regulate microtubule dynamics.This new function of DVL-1 in controlling microtubule stability may have important implications for Dishevelled proteins in regulating cell polarity.

View Article: PubMed Central - PubMed

Affiliation: The Randall Institute, King's College London, London, United Kingdom.

ABSTRACT
Dishevelled has been implicated in the regulation of cell fate decisions, cell polarity, and neuronal function. However, the mechanism of Dishevelled action remains poorly understood. Here we examine the cellular localization and function of the mouse Dishevelled protein, DVL-1. Endogenous DVL-1 colocalizes with axonal microtubules and sediments with brain microtubules. Expression of DVL-1 protects stable microtubules from depolymerization by nocodazole in both dividing cells and differentiated neuroblastoma cells. Deletion analyses reveal that the PDZ domain, but not the DEP domain, of DVL-1 is required for microtubule stabilization. The microtubule stabilizing function of DVL-1 is mimicked by lithium-mediated inhibition of glycogen synthase kinase-3beta (GSK-3beta) and blocked by expression of GSK-3beta. These findings suggest that DVL-1, through GSK-3beta, can regulate microtubule dynamics. This new function of DVL-1 in controlling microtubule stability may have important implications for Dishevelled proteins in regulating cell polarity.

Show MeSH
Related in: MedlinePlus