The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

GP ALPHA 1  -  guanine nucleotide-binding protein alpha-1...

Arabidopsis thaliana

Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

Disease relevance of GPA1


High impact information on GPA1

  • Surprisingly, S1P regulates stomatal apertures and guard cell ion channel activities in wild-type plants, but not in knockout lines of the sole prototypical heterotrimeric G-protein alpha-subunit gene, GPA1 (refs 5, 6, 7-8) [2].
  • We found that Arabidopsis thaliana plants harboring transferred DNA insertional mutations in the sole prototypical heterotrimeric GTP-binding (G) protein alpha subunit gene, GPA1, lack both ABA inhibition of guard cell inward K(+) channels and pH-independent ABA activation of anion channels [3].
  • Results from loss of function and ectopic expression and activation of GPA1 indicate that this subunit is a positive modulator of cell division in plants [4].
  • Inducible overexpression of GPA1 in Arabidopsis confers inducible ectopic cell division [4].
  • The alpha subunit of a prototypical heterotrimeric GTP-binding protein (G protein), which is encoded by a single gene (GPA1) in Arabidopsis, is a modulator of plant cell proliferation. gpa1 null mutants have reduced cell division in aerial tissues throughout development [4].

Biological context of GPA1


Anatomical context of GPA1


Associations of GPA1 with chemical compounds


Physical interactions of GPA1

  • However, whether GCR1 actually interacts with GPA1 was unknown [10].
  • One of the identified GPA1-interacting proteins is the cupin-domain protein AtPirin1 [11].

Other interactions of GPA1

  • We demonstrate by in vitro pull-down assays, by yeast split-ubiquitin assays, and by coimmunoprecipitation from plant tissue that GCR1 and GPA1 are indeed physically coupled [10].
  • These data indicate that AtPirin1 likely functions immediately downstream of GPA1 in regulating seed germination and early seedling development [11].
  • Single- and double-null mutants for the GPA1, AGB1 genes encoding the alpha and beta subunit of the heterotrimeric G protein, respectively, have wild-type sensitivity to R and FR [12].
  • The amino acid sequence of RGA1 was 77% and 86% identical to the sequences of alpha subunits from Arabidopsis thaliana and tomato (products of GPA1 and TGA1), respectively, and 42% to 69% identical to sequences of mammalian alpha subunits [13].
  • Using seeds that carry a null mutation in the genes encoding RGS protein (AtRGS1) and the alpha-subunit (AtGPA1) of the G protein in Arabidopsis (named rgs1-2 and gpa1-3, respectively), our genetic evidence proved the involvement of the AtRGS1 protein in the modulation of seed germination [14].

Analytical, diagnostic and therapeutic context of GPA1


  1. Biochemical characteristics of a rice (Oryza sativa L., IR36) G-protein alpha-subunit expressed in Escherichia coli. Seo, H.S., Choi, C.H., Lee, S.Y., Cho, M.J., Bahk, J.D. Biochem. J. (1997) [Pubmed]
  2. Sphingolipid signalling in Arabidopsis guard cells involves heterotrimeric G proteins. Coursol, S., Fan, L.M., Le Stunff, H., Spiegel, S., Gilroy, S., Assmann, S.M. Nature (2003) [Pubmed]
  3. G protein regulation of ion channels and abscisic acid signaling in Arabidopsis guard cells. Wang, X.Q., Ullah, H., Jones, A.M., Assmann, S.M. Science (2001) [Pubmed]
  4. Modulation of cell proliferation by heterotrimeric G protein in Arabidopsis. Ullah, H., Chen, J.G., Young, J.C., Im, K.H., Sussman, M.R., Jones, A.M. Science (2001) [Pubmed]
  5. The Plastid Protein THYLAKOID FORMATION1 and the Plasma Membrane G-Protein GPA1 Interact in a Novel Sugar-Signaling Mechanism in Arabidopsis. Huang, J., Taylor, J.P., Chen, J.G., Uhrig, J.F., Schnell, D.J., Nakagawa, T., Korth, K.L., Jones, A.M. Plant Cell (2006) [Pubmed]
  6. Molecular cloning and characterization of GPA1, a G protein alpha subunit gene from Arabidopsis thaliana. Ma, H., Yanofsky, M.F., Meyerowitz, E.M. Proc. Natl. Acad. Sci. U.S.A. (1990) [Pubmed]
  7. G-protein-coupled receptor 1, G-protein Galpha-subunit 1, and prephenate dehydratase 1 are required for blue light-induced production of phenylalanine in etiolated Arabidopsis. Warpeha, K.M., Lateef, S.S., Lapik, Y., Anderson, M., Lee, B.S., Kaufman, L.S. Plant Physiol. (2006) [Pubmed]
  8. Isolation of a putative receptor from Zea mays microsomal membranes that interacts with the G-protein, GP alpha 1. Wise, A., Thomas, P.G., White, I.R., Millner, P.A. FEBS Lett. (1994) [Pubmed]
  9. G-protein complex mutants are hypersensitive to abscisic acid regulation of germination and postgermination development. Pandey, S., Chen, J.G., Jones, A.M., Assmann, S.M. Plant Physiol. (2006) [Pubmed]
  10. The Arabidopsis putative G protein-coupled receptor GCR1 interacts with the G protein alpha subunit GPA1 and regulates abscisic acid signaling. Pandey, S., Assmann, S.M. Plant Cell (2004) [Pubmed]
  11. The Arabidopsis cupin domain protein AtPirin1 interacts with the G protein alpha-subunit GPA1 and regulates seed germination and early seedling development. Lapik, Y.R., Kaufman, L.S. Plant Cell (2003) [Pubmed]
  12. A reevaluation of the role of the heterotrimeric G protein in coupling light responses in Arabidopsis. Jones, A.M., Ecker, J.R., Chen, J.G. Plant Physiol. (2003) [Pubmed]
  13. Molecular cloning and characterization of a cDNA for the alpha subunit of a G protein from rice. Ishikawa, A., Tsubouchi, H., Iwasaki, Y., Asahi, T. Plant Cell Physiol. (1995) [Pubmed]
  14. The regulator of G-protein signaling proteins involved in sugar and abscisic acid signaling in Arabidopsis seed germination. Chen, Y., Ji, F., Xie, H., Liang, J., Zhang, J. Plant Physiol. (2006) [Pubmed]
WikiGenes - Universities