Responses immediate-early

The events following the activation of Ras ultimately led to the activation of MAP kinase, followed by activation of expression of immediate-early response genes. Activation of MAP kinase requires two intermediate steps, both of which involve a phosphorylation (Figure 8.5). The immediate activator of MAP kinase is MAP-kinase-kinase (also called MAP kinase-ERK kinase, or MEK), a most unusual enzyme that phosphorylates MAP kinase on both a threonine (T) and a tyrosine (Y) residue. These are in the target-sequence seven residues (LTEYVATRWYRAPE) (Table 8.1)... 

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). 

Thomson S, Clayton AL, Hazzalin CA, Rose S, Barratt MJ, Mahadevan LC (1999) The nucleosomal response associated with immediate-early gene induction is mediated via alternative MAP kinase cascades MSKl as a potential histone H3/HMG-14 kinase. Embo J 18(17) 4779-4793 Trivier E, De Cesare D, Jacquot S, Pannetier S, Zackai E, Young I, Mandel JL, Sassone-Corsi P, Hanauer A (1996) Mutations in the kinase Rsk-2 associated with Coffin-Lowry syndrome. Nature 384(6609) 567-570... 

Downstream targets of ERKl/2 and CREB include immediate early genes, such as c-Eos, FosB and Zif268, which are expressed in response to drugs of abuse... 

Van Gelder How do you reconcile the action spectrum data with the vitamin A-depletion data that we have presented As the perspective for this, in Neurospora, entrainment of the clock is resistant to vitamin A metabolic defects and in Drosophila it is resistant to vitamin A depletion. We found a similar result in the mammal with near-complete vitamin A depletion of the eye, and no attenuation in the response, as measured by immediate-early gene induction in the SCN. 

Norepinephrine may also play a role in the induction of immediate early genes in response to pup exposure (Thomas and Palmiter, 1997). Norepinephrine has been linked to maternal behavior in certain other animal models, such as sheep and rats. It may also play a role in olfactory recognition and memory in rats. Intraventricular administration of 6-OHDA prior to birth has been noted to impair postpartum maternal behavior administration after birth had no such effect. 

The presence of CaMKIV is positively correlated with the phosphorylation of CREB on S133, and with the expression of several immediate early genes in response to TCR-mediated activation of thymocytes and T cells, or with the expression of anti-apoptotic genes such as Bcl-2 in hematopoietic stem cells. Whether this correlation is a cause-effect relationship or just parallel events that occur during the relevant activation process triggered by CaMKIV needs to be clarified. For example, since... 

Terao A, Greco MA, Davis RW, Heller HC, Kilduff TS. Region-specific changes in immediate early gene expression in response to sleep deprivation and recovery sleep in the mouse brain. Neuroscience 2003 120 1115-1124. 

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