FosB proto-oncogene, AP-1 transcription factor subunit (FOSB)

FosB proto-oncogene, AP-1 transcription factor subunit (FOSB), encodes a leucine zipper transcription factor that dimerizes with JUN family members to form the AP-1 complex. This complex binds to specific DNA motifs (TRE: 5'-TGAG/CTCA-3') in the promoter regions of target genes, regulating their transcription. FOSB is critical for cellular proliferation, differentiation, and transformation; it is rapidly induced by extracellular stimuli and plays roles in neurogenesis, learning, memory, and nurturing behavior. A notable splice variant, ΔFosB, accumulates in the brain after chronic stressors (including drugs of abuse), mediating long-term neuroadaptations and addiction-related phenotypes. FOSB/AP-1 activity is implicated in several cancers, including leukemia, and regulates genes linked to inflammation, apoptosis, and cell survival. The AP-1 complex has been considered challenging to target pharmacologically, but new approaches exploit unique structural features such as a redox switch within ΔFosB to achieve specificity[1][2][3][4][6].

Other names

Protein FosBG0/G1 switch regulatory protein 3GOS3AP-1FBJ murine osteosarcoma viral oncogene homolog BTranscription factor AP-1 subunit FosBActivator protein 1FOS-BMGC42291DKFZp686C0818

Drugs and stimuli induce FosB/ΔFosB through chronic cellular stress, which subsequently alters gene transcription and neuroplasticity. Small molecules may target the cysteine-based redox switch critical for DNA binding and transcriptional activity of ΔFosB. Changes in FOSB activity modulate downstream genes that regulate reward, learning, cell survival, proliferation, and inflammation.