Sci. STKE, 9 November 2004
NEUROSCIENCE Follow the Bouncing Centrosome
During central nervous system development, neurons migrate along glial fibers to form laminar structures such as the cerebral and cerebellar cortexes. Migration proceeds in steps: Neurons extend a leading process forward and the nucleus, which is surrounded by a microtubular "cage," then follows. Disruption of the cytoskeleton and of nuclear movement interferes with neuronal migration (see Samuels and Tsai). Solecki et al. visualized cytoskeletal dynamics during neuronal migration of mouse P6 cerebellar granule cells cultured with cerebellar glia and saw that, during forward movement, the perinuclear cage (labeled with fluorescently tagged α-tubulin) first elongated and then moved forward together with the nucleus to resume its initial form. Fluorescently labeled mPar6α [a protein that functions with protein kinase C (PKC) as part of a cell polarity complex] was localized to a punctate structure identified by immunolabeling as the neuronal centrosome (the microtubule organizing center). Imaging revealed that movement of the centrosome into the leading process preceded that of the nucleus. Granule cells that overexpressed mPar6α did not migrate along glia; these cells showed dispersal of mPar6α, PKC, and -tubulin from the centrosome, a loss of centrosomal motility, and disintegration of the perinuclear cage. Knockdown of mPar6α with short hairpin RNA also resulted in a loss of centrosomal motility. Thus, mPar6α signaling from the centrosome appears to be critically involved in regulating cytoskeletal dynamics and nuclear translocation during neuronal migration along glia.
D. J. Solecki, L. Model, J. Gaetz, T. M. Kapoor, M. E. Hatten, Par6α signaling controls glial-guided neuronal migration. Nature Neurosci. 7, 1195-1203 (2004). [Online Journal]
B. A. Samuels, L.-H. Tsai, Nucleokinesis illuminated. Nature Neurosci. 7, 1169-1170 (2004). [Online Journal]
Citation: Follow the Bouncing Centrosome. Sci. STKE 2004, tw405 (2004).
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