Download MendeleyStructure-function analysis of plant G-protein regulatory mechanisms identifies key G alpha-RGS protein interactions.
Torres-Rodriguez, M.D., Lee, S.G., Roy Choudhury, S., Paul, R., Selvam, B., Shukla, D., Jez, J.M., Pandey, S.(2024) J Biol Chem 300: 107252-107252
- PubMed: 38569936
- DOI: https://doi.org/10.1016/j.jbc.2024.107252
- Primary Citation of Related Structures:
8VGA, 8VGB - PubMed Abstract:
Heterotrimeric GTP-binding protein alpha subunit (G¦Á) and its cognate regulator of G-protein signaling (RGS) protein transduce signals in eukaryotes spanning protists, amoeba, animals, fungi, and plants. The core catalytic mechanisms of the GTPase activity of G¦Á and the interaction interface with RGS for the acceleration of GTP hydrolysis seem to be conserved across these groups; however, the RGS gene is under low selective pressure in plants, resulting in its frequent loss. Our current understanding of the structural basis of G¦Á:RGS regulation in plants has been shaped by Arabidopsis G¦Á, (AtGPA1), which has a cognate RGS protein. To gain a comprehensive understanding of this regulation beyond Arabidopsis, we obtained the x-ray crystal structures of Oryza sativa G¦Á, which has no RGS, and Selaginella moellendorffi (a lycophyte) G¦Á that has low sequence similarity with AtGPA1 but has an RGS. We show that the three-dimensional structure, protein-protein interaction with RGS, and the dynamic features of these G¦Á are similar to AtGPA1 and metazoan G¦Á. Molecular dynamic simulation of the G¦Á-RGS interaction identifies the contacts established by specific residues of the switch regions of GTP-bound G¦Á, crucial for this interaction, but finds no significant difference due to specific amino acid substitutions. Together, our data provide valuable insights into the regulatory mechanisms of plant G-proteins but do not support the hypothesis of adaptive co-evolution of G¦Á:RGS proteins in plants.
Organizational Affiliation:
Donald Danforth Plant Science Center, St Louis, Missouri, USA.
