Jiang H, Guo W, Liang X H, and Rao Y*, Both the establishment and the maintenance of neuronal polarity require active mechanisms: critical roles of GSK-3beta and its upstream regulators, CELL, 120(1):123-135, 2005.

Abstract Axon-dendrite polarity is a cardinal feature of neuronal morphology essential for information flow. Here we report a differential distribution of GSK-3beta activity in the axon versus the dendrites. A constitutively active GSK-3beta mutant inhibited axon formation, whereas multiple axons formed from a single neuron when GSK-3beta activity was reduced by pharmacological inhibitors, a peptide inhibitor, or siRNAs. An active mechanism for maintaining neuronal polarity was revealed by the conversion of preexisting dendrites into axons upon GSK-3 inhibition. Biochemical and functional data show that the Akt kinase and the PTEN phosphatase are upstream of GSK-3beta in determining neuronal polarity. Our results demonstrate that there are active mechanisms for maintaining as well as esta......