Skip to main content
. 2005 Sep;25(18):7988–8000. doi: 10.1128/MCB.25.18.7988-8000.2005

FIG. 6.

FIG. 6.

Both S368 and S372 are required for the EGF-induced mobility shift of GGA3. (A) Myc-tagged, full-length GGA3 with mutations in S368A or S372A were expressed in M1 cells and analyzed for EGF-induced phosphorylation as described in the legend to Fig. 4. The asterisk indicates the position of phosphorylated GGA3. (B) Myc-tagged, full-length GGA3 with mutations in S368A (top panel) or S372A (middle panel) was expressed in resting M1 cells and analyzed by two-dimensional isoelectric focusing (IEF)/SDS-PAGE and immunoblotting with antibody to GGA3. To compare the migration of the two mutant species, both samples were also mixed and loaded together on the gels (lower panel). (C) M1 cells expressing Myc-tagged, full-length GGA3 S368A mutant were incubated in the absence (−EGF) or presence (+EGF) of 10 nM EGF and cell lysates were analyzed by SDS-PAGE/IEF and immunoblotting with antibody to GGA3. In panels B and C, asterisks indicate the position of endogenous, unphosphorylated GGA3. (E) Model for the dual-phosphorylation mechanism of GGA3 (see text for details).