Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2002;14 Suppl(Suppl):S355-73.
doi: 10.1105/tpc.001792.

Heterotrimeric and unconventional GTP binding proteins in plant cell signaling

Sarah M Assmann  1
Affiliations
Review

Heterotrimeric and unconventional GTP binding proteins in plant cell signaling

Sarah M Assmann. Plant Cell. 2002.
No abstract available

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Mammalian Heterotrimeric G-Protein Cycle. (A) Classic heterotrimeric GTPase cycle. Ligand (L) binding to a GPCR activates the associated G protein, promoting Gα and/or Gβγ interaction with downstream effectors (E). Intrinsic GTPase activity of the Gα subunit eventually returns the G protein to an inactive state. The Gα subunit remains closely associated with the plasma membrane. (B) Certain Gαs (von Zastrow and Mostov, 2001; Zheng et al., 2001) can show dissociation from the plasma membrane upon GPCR activation, contingent upon the absence or removal of lipid modification and the presence of regulatory (R) proteins.
Figure 2.
Figure 2.
Lipid Modifiers and Effectors of G Proteins. (A) Three types of G protein lipid modifications are shown. N-Myristoylation occurs by the attachment of the saturated fatty acid myristate (blue) to a conserved acceptor Gly (red) next to the initiator Met via a stable amino bond. In palmitoylated proteins, the saturated 16-carbon fatty acid palmitate (blue) is attached to Cys residues (red) via a labile thioester bond. Protein prenylation involves the attachment of the 15- and 20-carbon isoprenes farnesyl and geranylgeranyl (blue), respectively, to conserved Cys residues (red) at the C-terminal ends of proteins via a nonreversible thioester bond. The acceptor Cys residues are part of a conserved CaaX box motif in which C indicates Cys, a represents an aliphatic amino acid, and X is usually Ser, Met, Cys, Ala, Gln, or Leu. Ct and Nt indicate C- and N-terminal amino acid positions, respectively, relative to the acceptor amino acid. Proteolysis removes the final three amino acids, and the new C-terminal Cys is then prenylated. The Arabidopsis prototypical GPA1 contains a conserved myristoylation motif and a putative sequence for palmitoylation in the N-terminal region. The two Arabidopsis G protein γ subunits (AGG1 and AGG2) contain a prenyl group binding site in the C-terminal region. (B) Cleavage sites and hydrolysis products of phospholipases regulated by G proteins. PLA2 is an acylhydrolase that specifically removes the acyl chain from the sn-2 position of the glycerol backbone (black). PLD and PI-PLC are phosphodiesterases that generate similar products, except that the phosphate group (blue) either stays with the lipid moiety (black) or goes with the head group (red). DAG, sn-1-palmitoyl,2-linoleoyl diacylglycerol; Ins(1,4,5)P3, inositol 1,4,5-trisphosphate; LysoPtdCho, sn-1-lysophosphatidylcholine; PtdCho, sn-1-palmitoyl,2-linoleoyl phosphatidylcholine; PtdIns(4,5)P2, phosphatidylinositol 4,5-bisphosphate; PtdOH, sn-1-palmitoyl,2-linoleoyl phosphatidate.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Aharon, G.S., Snedden, W.A., and Blumwald, E. (1998). Activation of a plant plasma membrane Ca2+ channel by TGα1, a heterotrimeric G protein α-subunit homologue. FEBS Lett. 424 17–21. - PubMed
    1. Alpert, K.B., and Tanksley, S.D. (1996). High-resolution mapping and isolation of a yeast artificial chromosome contig containing fw2.2, a major fruit weight quantitative trait locus in tomato. Proc. Natl. Acad. Sci. USA 93 15503–15507. - PMC - PubMed
    1. Ando, S., Takumi, S., Ueda, Y., Ueda, T., Mori, N., and Nakamura, C. (2000). Nicotiana tabacum cDNAs encoding α and β subunits of a heterotrimeric GTP-binding protein isolated from hairy root tissues. Genes Genet. Syst. 75 211–221. - PubMed
    1. Armstrong, F., and Blatt, M.R. (1995). Evidence for K+ channel control in Vicia guard cells coupled by G-proteins to a 7TMS receptor mimetic. Plant J. 8 187–198.
    1. Ashikari, M., Wu, J., Yano, M., Sasaki, T., and Yoshimura, A. (1999). Rice gibberellin-insensitive dwarf mutant gene Dwarf 1 encodes the α-subunit of GTP-binding protein. Proc. Natl. Acad. Sci. USA 96 10284–10289. - PMC - PubMed

Publication types

MeSH terms

LinkOut - more resources