ΔFosB

links: reference: 8-16-2021

ΔFOSB (FBJ murine osteosarcoma viral oncogene homolog B) #

Splice variant of FOSB.

• Function and increase in expression is inhibited by by G9a (a histone methyltransferase), and ΔJunD.

• Delta FosB mediates epigenetic desensitization of the c-fos gene after chronic amphetamine exposure

  • ΔFosB recruits HDAC 1 to c-Fos’s gene promoter (on chromatin or something?) thus decreasing its mRNA; c-Fos being a transcription factor necessary for dopamine’s effects and for plasticity.
    • Chronic Amphetamine increases histone H3 methylation on the c-fos promoter, a chromatin modification also known to repress gene activity
    • How does c-Fos regulater dopamine sensitivyt, etc.? It might be something like c-Fos -> AP-1.
  • FosB represses expression of GluR2, CDK5, Dynorphin. And then of course c-Fos, which forms a positive feedback loop. I believe c-Fos normally degrades FosB or something.