Below is an interactive flash movie of the different steps involved in growth factor receptor activation of the MAP kinase pathway.
- Growth factor bind to receptor and cause dimerization.
- Dimerization leads to cross phosphorylation on tyrosine residues
- Grb2 bind to tyrosine phosphate by SH2 domain
- SH3 domain of Grb2 bind to SOS/CDC25 and recruits it to the membrane
- SOS/CDC25 is an GTP exchange factor for the small G protein Ras
- GTP exchange of Ras activates Ras
- Active Ras moves on and cause a conformatioal change in Raf1
- Conformational change in Raf1 is followed by single phosphorylation of Raf1
- Single phosphorylation lead to further phosphorylation of Raf1
- The 14-3-3 chaperone bind to phosphorylated Raf1 and stabilizes the active form of Raf1 that is now free to move on and activate the MAP kinase cascade.
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Plug-in
Flash
