1                                              p120 GAP accelerates the conversion of activated Ras-GTP

2 teract with Ras superfamily members, such as p120 GAP.

3 ociation of p190 Rac/Rho GAP with endogenous p120 GAP, N-GAP may form nonproductive complexes with co

4 ctive complexes with components critical for p120 GAP function.

5 d that Ras GTPase-activating proteins (GAPs; p120-GAP and NF1-GAP) stimulated wild-type TC21 GTP hydr

6  Rsu-1 transfectants, and immunoprecipitated p120 GAP from the Rsu-1 transfectants showed less Ras GT

7 ssibility that SH2 domain point mutations in p120 GAP detected in some basal cell carcinomas reduce c

8 mains within this region partially inhibited p120 GAP activity.

9 a targeted mutation in another GAP molecule, p120-GAP, demonstrated no increases in cerebral astrocyt

10 omology domain binds the catalytic domain of p120 GAP and interferes with the Ras/GAP interaction.

11            The pleckstrin homology domain of p120 GAP is located in the NH(2)-terminal, noncatalytic

12 ggest that the pleckstrin homology domain of p120 GAP may specifically regulate the interaction of Ra

13 f the isolated pleckstrin homology domain of p120 GAP specifically inhibits Ras-mediated signaling an

14 verexpression of the noncatalytic domains of p120 GAP may modulate Ras signal transduction pathways.

15   Furthermore, a dominant negative mutant of p120 GAP (designated N-GAP), a candidate Ras effector, b

16  that sequences in the SH2/SH3/SH2 region of p120 GAP are required for full catalytic activity toward

17 n the NH(2)-terminal, noncatalytic region of p120 GAP.

18 variable hydrophobic region had no effect on p120 GAP activity, deletion of the entire SH2/SH3/SH2 re

19 s for the N-terminal sequences in regulating p120 GAP catalytic activity and mitogenic signaling path

20                                  In summary, p120 GAP may function as an effector for Ras activation

21      Together with earlier findings that the p120 GAP SH2 domains mediate interactions with several G

22 fically regulate the interaction of Ras with p120 GAP via competitive intra-molecular binding.