c-fos genes refer to a group of immediate-early genes (IEGs) encoding the synthesis of the c-Fos protein. The term "c-fos" stands for cellular FBJ osteosarcoma oncogene, as it was originally discovered as a proto-oncogene in avian sarcoma virus (ASV) and later identified in mammalian cells. The c-fos genes belong to a family of transcription factors that play a pivotal role in regulating gene expression and are activated in response to various extracellular stimuli.
The c-fos genes are considered early response genes as they are rapidly and transiently activated following stimulation. They are involved in diverse cellular processes, including cell proliferation, differentiation, survival, and plasticity. The c-Fos protein forms a heterodimeric complex with Jun proteins (e.g., c-Jun) to create the transcription factor AP-1 (activator protein 1), which binds to DNA and regulates the activity of other genes.
Activation of c-fos genes occurs via several signaling pathways, such as the mitogen-activated protein kinase (MAPK) pathway, G-protein-coupled receptor (GPCR) signaling, and calcium signaling. Upon stimulation, these pathways lead to the phosphorylation and activation of transcription factors, which then bind to specific DNA sequences in the c-fos gene promoter region, initiating gene transcription.
The expression of c-fos genes has been extensively studied in the context of neuronal activity and plasticity in the brain. They are implicated in various physiological and pathological processes in the central nervous system, including memory formation, synaptic plasticity, neurodevelopmental disorders, and neuronal degeneration.
Overall, c-fos genes play a crucial role in cellular responses to a wide range of stimuli and serve as key regulators of gene
