Concentration and Localization of Coexpressed ELAV/Hu Proteins Control Specificity of mRNA Processing

Mol Cell Biol. 2015 Sep;35(18):3104-15. doi: 10.1128/MCB.00473-15. Epub 2015 Jun 29.

Abstract

Neuronally coexpressed ELAV/Hu proteins comprise a family of highly related RNA binding proteins which bind to very similar cognate sequences. How this redundancy is linked to in vivo function and how gene-specific regulation is achieved have not been clear. Analysis of mutants in Drosophila ELAV/Hu family proteins ELAV, FNE, and RBP9 and of genetic interactions among them indicates that they have mostly independent roles in neuronal development and function but have converging roles in the regulation of synaptic plasticity. Conversely, ELAV, FNE, RBP9, and human HuR bind ELAV target RNA in vitro with similar affinities. Likewise, all can regulate alternative splicing of ELAV target genes in nonneuronal wing disc cells and substitute for ELAV in eye development upon artificially increased expression; they can also substantially restore ELAV's biological functions when expressed under the control of the elav gene. Furthermore, ELAV-related Sex-lethal can regulate ELAV targets, and ELAV/Hu proteins can interfere with sexual differentiation. An ancient relationship to Sex-lethal is revealed by gonadal expression of RBP9, providing a maternal fail-safe for dosage compensation. Our results indicate that highly related ELAV/Hu RNA binding proteins select targets for mRNA processing through alteration of their expression levels and subcellular localization but only minimally by altered RNA binding specificity.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alternative Splicing / genetics
  • Animals
  • Drosophila Proteins / biosynthesis
  • Drosophila Proteins / genetics*
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / genetics*
  • ELAV Proteins / genetics
  • ELAV Proteins / metabolism*
  • Eye / embryology
  • Gene Expression Regulation / genetics
  • Nerve Tissue Proteins / biosynthesis
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism*
  • Neurogenesis / genetics*
  • Protein Binding
  • RNA-Binding Proteins / biosynthesis
  • RNA-Binding Proteins / genetics*
  • RNA-Binding Proteins / metabolism*
  • Sex Differentiation / genetics
  • Wings, Animal / cytology

Substances

  • Drosophila Proteins
  • ELAV Proteins
  • ELAV protein, Drosophila
  • Nerve Tissue Proteins
  • RNA-Binding Proteins
  • Rbp9 protein, Drosophila
  • Sxl protein, Drosophila
  • fne protein, Drosophila