The RNA-binding protein MARTA2 regulates dendritic targeting of MAP2 mRNAs in rat neurons

J Neurochem. 2013 Mar;124(5):670-84. doi: 10.1111/jnc.12079. Epub 2013 Jan 20.

Abstract

Dendritic targeting of mRNAs encoding the microtubule-associated protein 2 (MAP2) in neurons involves a cis-acting dendritic targeting element. Two rat brain proteins, MAP2-RNA trans-acting protein (MARTA)1 and MARTA2, bind to the cis-element with both high affinity and specificity. In this study, affinity-purified MARTA2 was identified as orthologue of human far-upstream element binding protein 3. In neurons, it resides in somatodendritic granules and dendritic spines and associates with MAP2 mRNAs. Expression of a dominant-negative variant of MARTA2 disrupts dendritic targeting of endogenous MAP2 mRNAs, while not noticeably altering the level and subcellular distribution of polyadenylated mRNAs as a whole. Finally, MAP2 transcripts associate with the microtubule-based motor KIF5 and inhibition of KIF5, but not cytoplasmic dynein function disrupts extrasomatic trafficking of MAP2 mRNA granules. Thus, in neurons MARTA2 appears to represent a key trans-acting factor involved in KIF5-mediated dendritic targeting of MAP2 mRNAs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Dendrites / metabolism*
  • Dendrites / ultrastructure
  • Immunohistochemistry
  • Immunoprecipitation
  • In Situ Hybridization
  • Mass Spectrometry
  • Microscopy, Immunoelectron
  • Microtubule-Associated Proteins / metabolism*
  • Neurons / metabolism*
  • Neurons / ultrastructure
  • Protein Transport / physiology
  • RNA, Messenger / metabolism*
  • RNA-Binding Proteins / metabolism*
  • Rats
  • Real-Time Polymerase Chain Reaction
  • Reverse Transcriptase Polymerase Chain Reaction

Substances

  • Fubp3 protein, rat
  • MAP2 protein, rat
  • Microtubule-Associated Proteins
  • RNA, Messenger
  • RNA-Binding Proteins