Early gene 2 factor

Immediate early genes, e.g., c-fos, c-jun, and c-myc, are the first genes whose expression is induced in cells after a growth stimulus. They encode transcription factors and induce the expression of other growth-related genes. 

The immediate early gene product c-Fos (cellular feline osteosarcoma) has widely been used as a useful marker of neuronal activation. Fos, the protein encoded by the c-fos gene, is a transcription factor that triggers transcription in a cascade of cellular responses. To determine which neuron groups are involved in the response to PGD2 and/or adenosine, especially A2aR agonists, we examined Fos-immunoreactivity under these conditions (Scammell et al., 1998, 2001 Satoh et al., 1999). 

Recent investigations into intracellular events have begun to define the postsynaptic events through which TCAs appear to exert their effects (Morinobu et ah, 1995). One of the observations made was down-regulation of transcription factors for early gene products such as c-Fos. C-Fos is normally produced in response to periods of stress. In research with rats, TCAs as well as other antidepressants have been shown to decrease the expression of c-Fos in areas of frontal cortex after chronic but not acute treatment. Other psychotropic medications (e.g., cocaine and haloperidol) with similar acute effects on norepinephrine/serotonin neurotransmission have not shown this same chronic effect. It has been speculated that the decreased production of c-Fos is the end product of a cascade of events stimulated by increased norepinephrine levels (Morinobu et ah, 1995). 

FIGURE 2—38. How early genes activate late genes, part 3. Once Fos and Jun proteins are synthesized, they can collaborate as partners and produce a Fos-Jun combination protein, which now acts as a transcription factor for late genes. Sometimes the Fos-Jun transcription factor is called a leucine zipper. 

Kato Y, Kravchenko VV, Tapping RI, Han J, et al. 1997. BMK1/ERK5 regulates serum-induced early gene expression through transcription factor MEF2C. EMBO J. 16 7054-7066. 

Figure 4. Schematic representation of the Ca2+/CaM/CaMKK/CaMKIV/CREB/immediate early genes/IL pathway in T cells. Activation only takes place after the triple stimulation of the TCR, IL-1R and CD4/8 receptors. The end point effect of CaMKIV, which is die synthesis of interleukins and other growth factors, is common to T cells and thymocytes. Interleukins and other growth factors may have an autocrine or a paracrine effect. The different pathways included here have been addressed using Camk4-/- mouse models. Since die role of die CaMK cascade in hematopoietic stem cells and neutrophils is a little different, they are not included here...

Egr2, early growth response 2 Zinc finger transcription factor, immediate early gene KO, KI... 

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