Neurotrophin regulation of beta-actin mRNA and protein localization within growth cones

J Cell Biol. 1999 Oct 4;147(1):59-70. doi: 10.1083/jcb.147.1.59.

Abstract

Neurotrophins play an essential role in the regulation of actin-dependent changes in growth cone shape and motility. We have studied whether neurotrophin signaling can promote the localization of beta-actin mRNA and protein within growth cones. The regulated localization of specific mRNAs within neuronal processes and growth cones could provide a mechanism to modulate cytoskeletal composition and growth cone dynamics during neuronal development. We have previously shown that beta-actin mRNA is localized in granules that were distributed throughout processes and growth cones of cultured neurons. In this study, we demonstrate that the localization of beta-actin mRNA and protein to growth cones of forebrain neurons is stimulated by neurotrophin-3 (NT-3). A similar response was observed when neurons were exposed to forskolin or db-cAMP, suggesting an involvement of a cAMP signaling pathway. NT-3 treatment resulted in a rapid and transient stimulation of PKA activity that preceded the localization of beta-actin mRNA. Localization of beta-actin mRNA was blocked by prior treatment of cells with Rp-cAMP, an inhibitor of cAMP-dependent protein kinase A. Depolymerization of microtubules, but not microfilaments, inhibited the NT-3-induced localization of beta-actin mRNA. These results suggest that NT-3 activates a cAMP-dependent signaling mechanism to promote the microtubule-dependent localization of beta-actin mRNA within growth cones.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Actin Cytoskeleton / drug effects
  • Actin Cytoskeleton / metabolism
  • Actins / genetics*
  • Actins / metabolism*
  • Animals
  • Cell Size / drug effects
  • Cells, Cultured
  • Chick Embryo
  • Colchicine / pharmacology
  • Culture Media
  • Cyclic AMP / analogs & derivatives
  • Cyclic AMP / metabolism
  • Cyclic AMP / pharmacology
  • Cyclic AMP-Dependent Protein Kinases / antagonists & inhibitors
  • Cyclic AMP-Dependent Protein Kinases / metabolism
  • Cytochalasin D / pharmacology
  • Enzyme Activation / drug effects
  • Gene Expression Regulation / drug effects
  • Growth Cones / drug effects
  • Growth Cones / enzymology
  • Growth Cones / metabolism*
  • Microtubules / drug effects
  • Microtubules / metabolism
  • Neurotrophin 3 / pharmacology*
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism*
  • Signal Transduction / drug effects

Substances

  • Actins
  • Culture Media
  • Neurotrophin 3
  • Protein Isoforms
  • RNA, Messenger
  • Cytochalasin D
  • Cyclic AMP
  • Cyclic AMP-Dependent Protein Kinases
  • Colchicine