![Loading full text...](/images/jp/spinner.gif)
Full text loading...
Heterotrimeric G-protein complexes couple extracellular signals via cell surface receptors to downstream enzymes called effectors. Heterotrimeric G-protein complexes, together with their cognate receptors and effectors, operate at the apex of signal transduction. In plants, the number of G-protein complex components is dramatically less than in other multicellular eukaryotes. An understanding of how multiple signals propagate transduction through the G-protein node can be found in the unique structural and kinetic properties of the plant heterotrimeric G-protein complex. This review addresses these unique features and speculates on why the repertoire of G-protein signaling elements is dramatically simpler than that in all other multicellular eukaryotes.
Article metrics loading...
Full text loading...
Data & Media loading...
Seventeen plant Gα subunits with 68 mammalian Gα subunits representing the four classes, Gαi, Gαs, Gαq, and Gα12/13 are compared in a multisequence line-up generated by Clustal W, optimized by T-COFFEE, and by eye using the crystal structure as a guide. Supplemental PDF #1 (309 KB)
Twelve plant Gβ subunits with 24 mammalian Gβ subunits representing the five classes, Gβ1–5 are compared in a multisequence line-up generated by Clustal W, optimized by T-COFFEE, and by eye using the crystal structure as a guide. Supplemental PDF #2 (131 KB)
Four plant Gγ subunits with 43 mammalian Gγ subunits representing the12 classes, Gγ1–12 are compared in a multisequence line-up generated by Clustal W, optimized by T-COFFEE, and by eye using the Gγ crystal structure as a guide. Supplemental PDF #3 (63 KB)
Seven plant Extra Large Gα subunits with 17 canonical plant and 68 mammalian Gα are compared in a multisequence line-up. Supplemental PDF #4 (KB)
Two putative plant phosducins are compared to three known mammalian phosducins in a multisequence line-up. Supplemental PDF #5 (690 KB)
The C-terminal sequence of 8 plant Gα are compared to 4 human Gα of the Gαi class. Supplemental PDF #6 (22 KB)
A non-alignment based approached was used to identify candidate Arabidopsis GPCRs using the entire set of available Arabidopsis open reading frames. Coincidence of one alignment-based method and 4 non-alignment methods were used to assess of 28,926 predicted proteins (Moriyama, et al. 2006). Provided is an Supplemental spreadsheet (Excel) containing a list of 394 candidates with Arabidopsis accession numbers provided and a tentative annotation. The length provided is the number of amino acids. TM is the number of predicted transmembrane spans and "N-term" is the prediction of whether the N-terminus is predicted to be extracellular (out) or cytosolic (in). If this candidate has already been recognized as a 7TM protein, the designation is indicated in the GPCR column. Using the sort function in Excel to cluster the group of candidates having 7TM with the N-terminus predicted to be external yields 54 candidate Arabidopsis GPCRs. For additional information, contact: Etsuko N. Moriyama ([email protected])
For a complete description on how these candidates where identified see: Moriyama, et al., (2006) Mining the Arabidopsis thaliana genome for highly-divergent seven transmembrane receptors. Genome Biology (in press)