Strittmatter SM, Fishman MC, Zhu XP. 1994. Activated mutants of the alpha subunit of G(o) promote an increased number of neurites per cell. The Journal of neuroscience : the official journal of the Society for Neuroscience. 14(4):2327-38. Pubmed: 8158271


The high concentration of the GTP-binding protein G(o) in the neuronal growth cone suggests that G(o) activation state may after neurite outgrowth. We find that activation of pertussis toxin-sensitive G-proteins by mastoparan increases neurite outgrowth from neuroblastoma cells. To examine G(o) activation specifically, point mutations homologous to activating, oncogenic mutations in alpha i2 and alpha s were introduced into the alpha subunit of G(o). The stability of the alpha o mutants to tryptic digestion confirms that they are activated. When expressed in PC12 or N1E-115 cells, activated alpha o doubles total neurites length per cell, primarily by increasing the number of neurites per cell. The growth cones of cells expressing activated alpha o are narrower than control growth cones. Expression of wildtype alpha o or the activated alpha subunits of other G-proteins did not affect total neurite length per cell. Thus, factors that lead to activation of G(o) can modulate neurite number per cell.

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Photo of Mark C. Fishman

Mark C. Fishman’s group studies the heart-brain connection. They employ a range of genetic, developmental, and neurobiological tools in zebrafish to understand what the heart tells the brain, and how critical internal sensory systems adjust homeostatic and somatic behaviors, including social interactions.

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