| | Name | Initial Conc. (uM) | Volume (fL) | Buffered |
| 1 | GAP | 0.002 | 1000 | No |
| | GTPase-activating proteins. See Boguski and McCormick 1993 Nature 366:643-654 Turn off Ras by helping to hydrolyze bound GTP. This one is probably NF1, ie., Neurofibromin as it is inhibited by AA and lipids, and expressed in neural cells. p120-GAP is also a possible candidate, but is less regulated. Both may exist at similar levels. See Eccleston et al JBC 268(36) pp27012-19 Level=.002 |
| 2 | GAP* | 0 | 1000 | No |
| | Phosphorylated and inactive GAP. See Boguski and McCormick 1993 Nature 366:643-654 for a review. |
| 3 | GDP-Ras | 0.2 | 1000 | No |
| | GDP bound form. See Rosen et al Neuron 12 1207-1221 June 1994. the activation loop is based on Boguski and McCormick Nature 366 643-654 93 Assume Ras is present at about the same level as craf-1, 0.2 uM. Hallberg et al JBC 269:6 3913-3916 1994 estimate upto 5-10% of cellular Raf is assoc with Ras. Given that only 5-10% of Ras is GTP-bound, we need similar amounts of Ras as Raf. |
| 4 | GEF* | 0 | 1000 | No |
| | Phosphorylated and thereby activated form of GEF. See, e.g. Orita et al JBC 268:34 25542-25546 1993, Gulbins et al. It is not clear whether there is major specificity for tyr or ser/thr. |
| 5 | GTP-Ras | 0 | 1000 | No |
| | Only a very small fraction (7% unstim, 15% stim) of ras is GTP-bound. Gibbs et al JBC 265(33) 20437 |
| 6 | inact-GEF | 0.1 | 1000 | No |
| | This is the amount of inactive GEF available to the system. The value is the same as the estimated amount of SoS, though I treat it here as a different pool. Probably several molecules can function as GEFs and this is a simplification. Orita et al JBC 268(34):25542-25546 Gulbins et al 1994 Mol Cell Biol 14(2):906-913 |
