Signaling specificity provided by the Arabidopsis thaliana Heterotrimeric G-Protein gamma subunits AGG1 and AGG2 is partially but not exclusively provided through transcriptional regulation

Thung, Leena, Chakravorty, David, Trusov, Yuri, Jones, Alan M. and Botella, Jose Ramon (2013) Signaling specificity provided by the Arabidopsis thaliana Heterotrimeric G-Protein gamma subunits AGG1 and AGG2 is partially but not exclusively provided through transcriptional regulation. PLoS One, 8 3: e58503.1-e58503.11. doi:10.1371/journal.pone.0058503


Author Thung, Leena
Chakravorty, David
Trusov, Yuri
Jones, Alan M.
Botella, Jose Ramon
Title Signaling specificity provided by the Arabidopsis thaliana Heterotrimeric G-Protein gamma subunits AGG1 and AGG2 is partially but not exclusively provided through transcriptional regulation
Journal name PLoS One   Check publisher's open access policy
ISSN 1932-6203
Publication date 2013-03-01
Year available 2013
Sub-type Article (original research)
DOI 10.1371/journal.pone.0058503
Open Access Status DOI
Volume 8
Issue 3
Start page e58503.1
End page e58503.11
Total pages 11
Place of publication San Francisco, CA United States
Publisher Public Library of Science
Language eng
Subject 2700 Medicine
1300 Biochemistry, Genetics and Molecular Biology
1100 Agricultural and Biological Sciences
Abstract The heterotrimeric G-protein complex in Arabidopsis thaliana consists of one alpha, one beta and three gamma subunits. While two of the gamma subunits, AGG1 and AGG2 have been shown to provide functional selectivity to the G beta gamma dimer in Arabidopsis, it is unclear if such selectivity is embedded in their molecular structures or conferred by the different expression patterns observed in both subunits. In order to study the molecular basis for such selectivity we tested genetic complementation of AGG1- and AGG2 driven by the respectively swapped gene promoters. When expressed in the same tissues as AGG1, AGG2 rescues some agg1 mutant phenotypes such as the hypersensitivity to Fusarium oxysporum and D-mannitol as well as the altered levels of lateral roots, but does not rescue the early flowering phenotype. Similarly, AGG1 when expressed in the same tissues as AGG2 rescues the osmotic stress and lateral-root phenotypes observed in agg2 mutants but failed to rescue the heat-stress induction of flowering. The fact that AGG1 and AGG2 are functionally interchangeable in some pathways implies that, at least for those pathways, signaling specificity resides in the distinctive spatiotemporal expression patterns exhibited by each gamma subunit. On the other hand, the lack of complementation for some phenotypes indicates that there are pathways in which signaling specificity is provided by differences in the primary AGG1 and AGG2 amino acid sequences.
Formatted abstract
The heterotrimeric G-protein complex in Arabidopsis thaliana consists of one α, one ß and three γ subunits. While two of the γ subunits, AGG1 and AGG2 have been shown to provide functional selectivity to the Gßγ dimer in Arabidopsis, it is unclear if such selectivity is embedded in their molecular structures or conferred by the different expression patterns observed in both subunits. In order to study the molecular basis for such selectivity we tested genetic complementation of AGG1- and AGG2 driven by the respectively swapped gene promoters. When expressed in the same tissues as AGG1, AGG2 rescues some agg1 mutant phenotypes such as the hypersensitivity to Fusarium oxysporum and D-mannitol as well as the altered levels of lateral roots, but does not rescue the early flowering phenotype. Similarly, AGG1 when expressed in the same tissues as AGG2 rescues the osmotic stress and lateral-root phenotypes observed in agg2 mutants but failed to rescue the heat-stress induction of flowering. The fact that AGG1 and AGG2 are functionally interchangeable in some pathways implies that, at least for those pathways, signaling specificity resides in the distinctive spatiotemporal expression patterns exhibited by each γ subunit. On the other hand, the lack of complementation for some phenotypes indicates that there are pathways in which signaling specificity is provided by differences in the primary AGG1 and AGG2 amino acid sequences.
Keyword Plant Innate Immunity
Alpha Subunits
Abscisic Acid
Seed Germination
Channel Regulation
Developmental Processes
Q-Index Code C1
Q-Index Status Confirmed Code
Grant ID DP1094152
R01GM065989
MCB-0723515
DE-FG02-05er15671
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: School of Agriculture and Food Sciences
Official 2014 Collection
 
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Citation counts: TR Web of Science Citation Count  Cited 11 times in Thomson Reuters Web of Science Article | Citations
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