14-3-3ε Couples Protein Kinase A to Semaphorin Signaling and Silences Plexin RasGAP-Mediated Axonal Repulsion

Taehong Yang, Jonathan R. Terman

Research output: Contribution to journalArticlepeer-review

23 Scopus citations

Abstract

The biochemical means through which multiple signaling pathways are integrated in navigating axons is poorly understood. Semaphorins are among the largest families of axon guidance cues and utilize Plexin (Plex) receptors to exert repulsive effects on axon extension. However, Semaphorin repulsion can be silenced by other distinct cues and signaling cascades, raising questions of the logic underlying these events. We now uncover a simple biochemical switch that controls Semaphorin/Plexin repulsive guidance. Plexins are Ras/Rap family GTPase activating proteins (GAPs) and we find that the PlexA GAP domain is phosphorylated by the cAMP-dependent protein kinase (PKA). This PlexA phosphorylation generates a specific binding site for 14-3-3ε, a phospho-binding protein that we find to be necessary for axon guidance. These PKA-mediated Plexin-14-3-3ε interactions prevent PlexA from interacting with its Ras family GTPase substrate and antagonize Semaphorin repulsion. Our results indicate that these interactions switch repulsion to adhesion and identify a point of convergence for multiple guidance molecules. Yang and Terman find that the phosphobinding protein 14-3-3 . ε acts as a biochemical control point for axon guidance in . Drosophila, silencing Plexin A repulsive axon guidance and regulating a semaphorin repulsion/integrin adhesion switch.

Original languageEnglish (US)
Pages (from-to)108-121
Number of pages14
JournalNeuron
Volume74
Issue number1
DOIs
StatePublished - Apr 12 2012

ASJC Scopus subject areas

  • Neuroscience(all)

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