Regulation of dendritic branching and filopodia formation in hippocampal neurons by specific acylated protein motifs

Mol Biol Cell. 2004 May;15(5):2205-17. doi: 10.1091/mbc.e03-07-0493. Epub 2004 Feb 20.

Abstract

Although neuronal axons and dendrites with their associated filopodia and spines exhibit a profound cell polarity, the mechanism by which they develop is largely unknown. Here, we demonstrate that specific palmitoylated protein motifs, characterized by two adjacent cysteines and nearby basic residues, are sufficient to induce filopodial extensions in heterologous cells and to increase the number of filopodia and the branching of dendrites and axons in neurons. Such motifs are present at the N-terminus of GAP-43 and the C-terminus of paralemmin, two neuronal proteins implicated in cytoskeletal organization and filopodial outgrowth. Filopodia induction is blocked by mutations of the palmitoylated sites or by treatment with 2-bromopalmitate, an agent that inhibits protein palmitoylation. Moreover, overexpression of a constitutively active form of ARF6, a GTPase that regulates membrane cycling and dendritic branching reversed the effects of the acylated protein motifs. Filopodia induction by the specific palmitoylated motifs was also reduced upon overexpression of a dominant negative form of the GTPase cdc42. These results demonstrate that select dually lipidated protein motifs trigger changes in the development and growth of neuronal processes.

Publication types

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

MeSH terms

  • ADP-Ribosylation Factor 6
  • ADP-Ribosylation Factors / physiology
  • Acylation
  • Amino Acid Motifs / genetics
  • Amino Acid Motifs / physiology
  • Amino Acid Sequence
  • Amino Acids, Basic / genetics
  • Animals
  • COS Cells
  • Chlorocebus aethiops
  • Cysteine / genetics
  • Dendrites / physiology
  • Dendrites / ultrastructure*
  • GAP-43 Protein / genetics
  • GAP-43 Protein / physiology
  • Hippocampus / cytology*
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology
  • Molecular Sequence Data
  • Mutagenesis
  • Nerve Tissue Proteins / chemistry*
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / physiology
  • Neurons / cytology*
  • Neurons / physiology
  • Palmitates / pharmacology
  • Phosphoproteins
  • Pseudopodia / drug effects
  • Pseudopodia / physiology
  • Pseudopodia / ultrastructure*
  • Rats
  • Sequence Alignment
  • Transfection
  • cdc42 GTP-Binding Protein / physiology

Substances

  • ADP-Ribosylation Factor 6
  • Amino Acids, Basic
  • GAP-43 Protein
  • Membrane Proteins
  • Nerve Tissue Proteins
  • Palmitates
  • Phosphoproteins
  • postsynaptic density proteins
  • 2-bromopalmitate
  • ADP-Ribosylation Factors
  • Arf6 protein, rat
  • cdc42 GTP-Binding Protein
  • Cysteine