Article

Axonal elongation triggered by stimulus-induced local translation of a polarity complex protein

Department of Pharmacology, Weill Medical College, Cornell University, NY 10065, USA.
Nature Cell Biology (Impact Factor: 20.06). 09/2009; 11(8):1024-30. DOI: 10.1038/ncb1916
Source: PubMed

ABSTRACT During development, axon growth rates are precisely regulated to provide temporal control over pathfinding. The precise temporal regulation of axonal growth is a key step in the formation of functional synapses and the proper patterning of the nervous system. The rate of axonal elongation is increased by factors such as netrin-1 and nerve growth factor (NGF), which stimulate axon outgrowth using incompletely defined pathways. To clarify the mechanism of netrin-1- and NGF-stimulated axon growth, we explored the role of local protein translation. We found that intra-axonal protein translation is required for stimulated, but not basal, axon outgrowth. To identify the mechanism of translation-dependent outgrowth, we examined the PAR complex, a cytoskeleton regulator. We found that the PAR complex, like local translation, is required for stimulated, but not basal, outgrowth. Par3 mRNA is localized to developing axons, and NGF and netrin-1 trigger its local translation. Selective ablation of Par3 mRNA from axons abolishes the outgrowth-promoting effect of NGF. These results identify a new role for local translation and the PAR complex in axonal outgrowth.

Download full-text

Full-text

Available from: Ulrich Hengst, Aug 20, 2015
0 Followers
 · 
136 Views
  • Source
    • "Traditionally, silicon and glass were major materials for microfabrication; however, polydimethylsiloxane polymer-based microfluidic devices are the most widely used due to their advantages in biocompatibility, low cost, optical transparency, practical scalability, gas permeability and easy fabrication. In the field of neuroscience, microfluidic devices have been increasingly used to achieve spatial-temporal control of cellular microenvironments such as those of the axon and soma (for review see (Millet and Gillette, 2012; Harink et al., 2013; Park et al., 2013)) to investigate axon elongation, local signaling events (Hengst et al., 2009; Taylor et al., 2009) as well as interactions with other cells such as oligodendroglia (Park et al., 2012), astrocytes (Li et al., 2012) and microglia (Hosmane et al., 2012). We recently presented a microchip system that is capable of isolating CNS axons from neuronal cell bodies for quick and easy quantitative axonal growth analysis (Park et al., 2014) (Figure 1C, E, F). "
    Neural Regeneration Research 10/2014; 9(19):1703-1705. DOI:10.4103/1673-5374.143412 · 0.23 Impact Factor
  • Source
    • "In addition, induction of Scribble was attenuated by CHX treatment, which indicates that the observed changes in protein expression are regulated by translation . NGF thus drives transient Scribble induction possibly by increasing local protein translation, as been described for Par3 in neurons (Hengst et al., 2009). "
    [Show abstract] [Hide abstract]
    ABSTRACT: Neurite outgrowth is mediated by dynamic changes of the cytoskeleton and is largely controlled by Rho GTPases and their regulators. Here, we show that the polarity protein Scribble controls PC12 cell neurite outgrowth in response to nerve growth factor. Scribble knockdown decreases neurite numbers and increases neurite length. This effect is linked to TrkA the cognate receptor for NGF as pharmacological inhibition of phosphorylated TrkA (pTrkA) reduces Scribble expression. Moreover, Scribble forms a complex with the MAPK components ERK1/2 in a growth factor dependent manner. In RNAi experiments where Scribble expression is efficiently depleted sustained ERK1/2 phosphorylation is reduced. Conversely, siRNA with intermediate Scribble silencing efficiency fails to match this effect indicating that ERK1/2 activation depends on basic Scribble protein levels. Finally, Scribble translocates to the plasma membrane in response to growth factor where it complexes with HRas and Rac1 suggesting that the phenotype activated by loss of Scribble may be a result of altered GTPase activity. Together, these results demonstrate a novel role for Scribble in neurite outgrowth of PC12 cells.
    European journal of cell biology 07/2013; 92(6-7). DOI:10.1016/j.ejcb.2013.07.002 · 3.70 Impact Factor
  • Source
    • "The compartmentalization has been used to position electrode arrays (Dworak and Wheeler, 2009), femtosecond laser enabled axotomy (Kim et al. 2009) and a pneumatic compression based axotomy (Hosmane et al., 2011) selectively at just the axons. Another advantage is that the microtunnels can guide the axons to grow in straight lines, which makes it easy to track the growth rates of axons (Hengst et al., 2009) and to monitor axonal transport of molecules and organelles (Lu et al. 2012). Finally, microtunnel-based chips have been used to create networks between different cell populations. "
    [Show abstract] [Hide abstract]
    ABSTRACT: A microfluidic chip for culturing neurons and spatially isolating axons from somas is presented for use with visually guided whole-cell electrophysiological measurements. A modular design consisting of detachable and re-sealable layers is used to satisfy the requirements of both long-term neuron culturing as well as electrophysiological measurements. Whole cell patch clamp recordings indicate functional viability of neurons with isolated axons. Fluidic isolation was used to achieve asymmetric lentiviral infection of neurons on a single side reservoir. Neurons were asymmetrically infected with lentiviruses expressing the light-activated cationic channel channelrhodopsin-2. Light-evoked excitatory postsynaptic responses were detected by whole cell recordings of neurons on the uninfected side showing functional synaptic connectivity between the two isolated but axonally connected sides of the device.
    Journal of neuroscience methods 10/2012; 212(2). DOI:10.1016/j.jneumeth.2012.10.013 · 1.96 Impact Factor
Show more