c-Fos

A member of the transcription factor complex AP1

General Information

The Fos gene family consists of 4 members: c-Fos, FosB, FosL1, and FosL2, also called Fos related antigen 1 and 2 (FRA1 and 2). These leucine zipper proteins can dimerize with proteins of the JUN family leading to the formation of the transcription factor complex AP1.
The expression of Fos proteins is rapidly and transiently induced by different extracellular stimuli such as growth factors, cytokines, neurotransmitters, polypeptide hormones, stress.
In addition Fos proteins can be phosphorylated by ERK kinases modulating transcriptional activity, protein stability and localization. c-Fos is homologous to the Finkel-Biskis-Jinkins (FBJ) murine osteosarcoma virus oncogene.