Structural basis for the 14-3-3 protein-dependent inhibition of the regulator of G protein signaling 3 (RGS3) function.
Regulator of G protein signaling (RGS) proteins function as GTPase-activating proteins for the α-subunit of heterotrimeric G proteins. The function of certain RGS proteins is negatively regulated by 14-3-3 proteins, a family of highly conserved regulatory molecules expressed in all eukaryotes. In this study, we provide a structural mechanism for 14-3-3-dependent inhibition of RGS3-Gα interaction. We have used small angle x-ray scattering, hydrogen/deuterium exchange kinetics, and Förster resonance energy transfer measurements to determine the low-resolution solution structure of the 14-3-3ζ·RGS3 complex. The structure shows the RGS domain of RGS3 bound to the 14-3-3ζ dimer in an as-yet-unrecognized manner interacting with less conserved regions on the outer surface of the 14-3-3 dimer outside its central channel. Our results suggest that the 14-3-3 protein binding affects the structure of the Gα interaction portion of RGS3 as well as sterically blocks the interaction between the RGS domain and the Gα subunit of heterotrimeric G proteins.
Department of Physical and Macromolecular Chemistry, Charles University in Prague, 12843 Prague, Czech Republic.
Lenka
L
Rezabkova
Petr
P
Man
Petr
P
Novak
Petr
P
Herman
Jaroslav
J
Vecer
Veronika
V
Obsilova
Tomas
T
Obsil
D048948:14-3-3 Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002942:Circular Dichroism; D031541:Fluorescence Resonance Energy Transfer; D019204:GTP-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020690:GTPase-Activating Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D013058:Mass Spectrometry; D010766:Phosphorylation; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D020710:RGS Proteins; D053838:Scattering, Small Angle; D015398:Signal Transduction
D048948:14-3-3 Proteins; D020690:GTPase-Activating Proteins; D020710:RGS Proteins; C485898:RGS3 protein, human; D019204:GTP-Binding Proteins