Table 1.

Raf1 binding and effects of R-Ras mutants on ephrin-mediated repulsive responses

R-Ras construct RBD binding* Inhibits cell retraction Inhibits cell migration Inhibits growth-cone collapse
WT + No n.d. No
38V ++++§ Yes No Yes/no
38VY66F ++§ Yes Yes Yes
38VY66E § No No n.d.
Y66F + No No Yes
Y66E No†† n.d. n.d.
43N ** No†† n.d. n.d.
  • n.d., not determined.

  • * Independent of phosphorylation on tyrosine 66 because orthovanadate was not included in the buffers; RBD, Ras-binding domain of Raf1.

  • Induced by ephrin stimulation.

  • The R-Ras Y66E and 43N mutants do not cause cell retraction in the absence of ephrin, suggesting that R-Ras inactivation is not sufficient to cause cell retraction.

  • § See supplementary material Fig. S5.

  • Zou et al., 1999.

  • ** Based on the GTP-binding deficiency of this mutant.

  • †† Data not shown.