RT Journal Article
SR Electronic
T1 Signaling Networks in Neuronal Polarization
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 10626
OP 10630
DO 10.1523/JNEUROSCI.3824-06.2006
VO 26
IS 42
A1 Takeshi Yoshimura
A1 Nariko Arimura
A1 Kozo Kaibuchi
YR 2006
UL http://www.jneurosci.org/content/26/42/10626.abstract
AB A mature neuron is typically polarized both structurally and functionally, with a single long axon and several dendrites. Neuronal polarity is essential for unidirectional signal flow from somata or dendrites to axons. The initial event in establishing a polarized neuron is the specification of a single axon. Early in neuronal development, one immature neurite becomes differentiated from other neurites to form an axon. Although studies in the past two decades have yielded a catalog of structural, molecular, and functional differences between axons and dendrites, we are only now beginning to understand the molecular mechanisms involved in the establishment of neuronal polarity. In the last few years, neuronal polarity-regulating molecules have been revealed. There are two major signaling cascades in neuronal polarization. Several groups, including ours, reported that the phosphatidylinositol 3-kinase (PI3-kinase)/Akt/glycogen synthase kinase-3β (GSK-3β)/collapsin response mediator protein-2 pathway is important for axon specification and elongation. Recent studies have revealed that the positive feedback loop composed of Rho family small GTPases and the Par3/Par6/atypical protein kinase C complex plays a role in the initial events of neuronal polarization downstream of PI3-kinase. Here, we discuss the roles of signaling molecules for axon specification.