First Author | Kim WY | Year | 2006 |
Journal | Neuron | Volume | 52 |
Issue | 6 | Pages | 981-96 |
PubMed ID | 17178402 | Mgi Jnum | J:122936 |
Mgi Id | MGI:3716005 | Doi | 10.1016/j.neuron.2006.10.031 |
Citation | Kim WY, et al. (2006) Essential roles for GSK-3s and GSK-3-primed substrates in neurotrophin-induced and hippocampal axon growth. Neuron 52(6):981-96 |
abstractText | Glycogen synthase kinase-3beta (GSK-3beta) is thought to mediate morphological responses to a variety of extracellular signals. Surprisingly, we found no gross morphological deficits in nervous system development in GSK-3beta null mice. We therefore designed an shRNA that targeted both GSK-3 isoforms. Strong knockdown of both GSK-3alpha and beta markedly reduced axon growth in dissociated cultures and slice preparations. We then assessed the role of different GSK-3 substrates in regulating axon morphology. Elimination of activity toward primed substrates only using the GSK-3 R96A mutant was associated with a defect in axon polarity (axon branching) compared to an overall reduction in axon growth induced by a kinase-dead mutant. Consistent with this finding, moderate reduction of GSK-3 activity by pharmacological inhibitors induced axon branching and was associated primarily with effects on primed substrates. Our results suggest that GSK-3 is a downstream convergent point for many axon growth regulatory pathways and that differential regulation of primed versus all GSK-3 substrates is associated with a specific morphological outcome. |