G Proteins Go Green: A Plant G Protein Signaling FAQ Sheet
Sarah M. Assmann
Biology Department, Pennsylvania State University, 208 Mueller Laboratory, University Park, PA 16802, USA.
Fig. 1.. The G protein cycle. Components and processes found in both plants and animals are indicated in green, with darker green indicating more definitive evidence (in plants) than lighter green. Those components and processes to date reported only for plants are in purple and those reported only for animals are indicated in red. GEF (guanine nucleotide exchange factor) and GDI (guanine nucleotide dissociation inhibitor) are two G binding proteins so far only identified in animals. In addition to desensitization and internalization, arrestins also act as adapter proteins in the regulation of intracellular signaling. (inset) The round-leaf phenotype exhibited by G (gpa1) knockout plants of Arabidopsis (right), in this case, a plant with the mutant allele gpa1-4, in comparison with a wild-type plant of the Columbia-0 ecotype (Col-0) (left).
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