Induction and modulation of cerebellar granule neuron death by E2F-1

J Biol Chem. 2000 Aug 18;275(33):25358-64. doi: 10.1074/jbc.M001725200.

Abstract

Growing evidence suggests that certain cell cycle regulators also mediate neuronal death. Of relevance, cyclin D1-associated kinase activity is increased and the retinoblastoma protein (Rb), a substrate of the cyclin D1-Cdk4/6 complex, is phosphorylated during K(+) deprivation-evoked death of cerebellar granule neurons (CGNs). Cyclin-dependent kinase (CDK) inhibitors block this death, suggesting a requirement for the cyclin D1/Cdk4/6-Rb pathway. However, the downstream target(s) of this pathway are not well defined. The transcription factor E2F-1 is regulated by Rb and is reported to evoke death in proliferating cells when overexpressed. Accordingly, we examined whether E2F-1 was sufficient to evoke death of CGNs and whether it was required for death evoked by low K(+). We show that adenovirus-mediated expression of E2F-1 in CGNs results in apoptotic death, which is independent of p53, dependent upon Bax, and associated with caspase 3-like activity. In addition, we demonstrate that levels of E2F-1 mRNA and protein increase during K(+) deprivation-evoked death. The increase in E2F-1 protein is blocked by the CDK inhibitor flavopiridol. Finally, E2F-1-deficient neurons are modestly resistant to death induced by low K(+). These results indicate that E2F-1 expression is sufficient to promote neuronal apoptosis and that endogenous E2F-1 modulates the death of CGNs evoked by low K(+).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoviridae / metabolism
  • Animals
  • Apoptosis
  • Blotting, Western
  • Carrier Proteins*
  • Caspase 3
  • Caspases / metabolism
  • Cell Cycle Proteins*
  • Cell Death*
  • Cells, Cultured
  • Cerebellum / metabolism*
  • Cyclin D1 / metabolism
  • DNA-Binding Proteins*
  • E2F Transcription Factors
  • E2F1 Transcription Factor
  • Enzyme Inhibitors
  • Flavonoids / pharmacology
  • Fluorescent Antibody Technique
  • Lac Operon
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Neurons / cytology*
  • Neurons / metabolism
  • Piperidines / pharmacology
  • Potassium / metabolism
  • Proto-Oncogene Proteins / metabolism
  • Proto-Oncogene Proteins c-bcl-2*
  • RNA, Messenger / metabolism
  • Retinoblastoma-Binding Protein 1
  • Reverse Transcriptase Polymerase Chain Reaction
  • Signal Transduction
  • Time Factors
  • Transcription Factor DP1
  • Transcription Factors / genetics
  • Transcription Factors / physiology*
  • Tumor Suppressor Protein p53 / metabolism
  • bcl-2-Associated X Protein
  • beta-Galactosidase / metabolism

Substances

  • Arid4a protein, mouse
  • Bax protein, mouse
  • Carrier Proteins
  • Cell Cycle Proteins
  • DNA-Binding Proteins
  • E2F Transcription Factors
  • E2F1 Transcription Factor
  • E2f1 protein, mouse
  • Enzyme Inhibitors
  • Flavonoids
  • Piperidines
  • Proto-Oncogene Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • RNA, Messenger
  • Retinoblastoma-Binding Protein 1
  • Transcription Factor DP1
  • Transcription Factors
  • Tumor Suppressor Protein p53
  • bcl-2-Associated X Protein
  • Cyclin D1
  • alvocidib
  • beta-Galactosidase
  • Casp3 protein, mouse
  • Caspase 3
  • Caspases
  • Potassium