Transcription factor Pebbled/RREB1 regulates injury-induced axon degeneration

Proc Natl Acad Sci U S A. 2018 Feb 6;115(6):1358-1363. doi: 10.1073/pnas.1715837115. Epub 2018 Jan 2.

Abstract

Genetic studies of Wallerian degeneration have led to the identification of signaling molecules (e.g., dSarm/Sarm1, Axundead, and Highwire) that function locally in axons to drive degeneration. Here we identify a role for the Drosophila C2H2 zinc finger transcription factor Pebbled [Peb, Ras-responsive element binding protein 1 (RREB1) in mammals] in axon death. Loss of Peb in Drosophila glutamatergic sensory neurons results in either complete preservation of severed axons, or an axon death phenotype where axons fragment into large, continuous segments, rather than completely disintegrate. Peb is expressed in developing and mature sensory neurons, suggesting it is required to establish or maintain their competence to undergo axon death. peb mutant phenotypes can be rescued by human RREB1, and they exhibit dominant genetic interactions with dsarm mutants, linking peb/RREB1 to the axon death signaling cascade. Surprisingly, Peb is only able to fully block axon death signaling in glutamatergic, but not cholinergic sensory neurons, arguing for genetic diversity in axon death signaling programs in different neuronal subtypes. Our findings identify a transcription factor that regulates axon death signaling, and peb mutant phenotypes of partial fragmentation reveal a genetically accessible step in axon death signaling.

Keywords: Wallerian degeneration; axon death; axons.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified
  • Armadillo Domain Proteins / genetics
  • Armadillo Domain Proteins / metabolism
  • Axons / metabolism
  • Axons / pathology*
  • Cholinergic Neurons / pathology
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / genetics
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Wallerian Degeneration / genetics
  • Wallerian Degeneration / metabolism
  • Wallerian Degeneration / pathology*
  • Wings, Animal / innervation
  • Wings, Animal / metabolism
  • Zinc Fingers / genetics

Substances

  • Armadillo Domain Proteins
  • Cytoskeletal Proteins
  • DNA-Binding Proteins
  • Drosophila Proteins
  • Ect4 protein, Drosophila
  • Nuclear Proteins
  • RREB1 protein, human
  • Transcription Factors
  • peb protein, Drosophila