Abstract
RGC1 and RGC2 comprise a functional RalGAP complex (RGC) that suppresses RalA activity. The PI3-kinase/Akt signaling pathway activates RalA through phosphorylation-mediated inhibition of the RGC. Here we identify a novel phosphorylation-dependent interaction between 14-3-3 and the RGC. 14-3-3 binds to the complex through an Akt-phosphorylated residue, threonine 715, on RGC2. Interaction with 14-3-3 does not alter in vitro activity of the GTPase-activating protein complex. However, blocking the interaction between 14-3-3 and RGC2 in cells increases suppression of RalA activity by the RGC, suggesting that 14-3-3 inhibits the complex through a non-catalytic mechanism. Together, these data show that 14-3-3 negatively regulates the RGC downstream of the PI3-kinase/Akt signaling pathway.
Publication types
-
Research Support, N.I.H., Extramural
MeSH terms
-
14-3-3 Proteins / metabolism*
-
3T3 Cells
-
Adipocytes / cytology
-
Amino Acid Motifs
-
Androstadienes / pharmacology
-
Animals
-
DNA / metabolism
-
Enzyme Inhibitors / pharmacology
-
GTP-Binding Proteins / metabolism
-
GTPase-Activating Proteins / metabolism*
-
Gene Expression Regulation*
-
HEK293 Cells
-
Humans
-
Mice
-
Nerve Tissue Proteins / metabolism*
-
Phosphatidylinositol 3-Kinases / metabolism
-
Phosphoric Monoester Hydrolases / metabolism
-
Phosphorylation
-
Protein Binding
-
Signal Transduction
-
Wortmannin
-
ral GTP-Binding Proteins / metabolism*
Substances
-
14-3-3 Proteins
-
Androstadienes
-
Enzyme Inhibitors
-
GTPase-Activating Proteins
-
Nerve Tissue Proteins
-
RALGAPA1 protein, human
-
DNA
-
Phosphatidylinositol 3-Kinases
-
Phosphoric Monoester Hydrolases
-
GTP-Binding Proteins
-
RALA protein, human
-
ral GTP-Binding Proteins
-
Wortmannin