278
Entry URI http://metadb.riken.jp/db/SciNetS_ria224i/cria224u4ria224u16183844i
Entry name Johnson Cynthia D et al. 2005 Oct. Plant Physiol. 139(2):722-33.
Title Protein geranylgeranyltransferase I is involved in specific aspects of abscisic acid and auxin signaling in Arabidopsis.
Authors Chary S Narasimha|Chernoff Ellen A|Crowell Dring N|Johnson Cynthia D|Running Mark P|Zeng Qin
Abstract Arabidopsis (Arabidopsis thaliana) mutants lacking a functional ERA1 gene, which encodes the beta-subunit of protein farnesyltransferase (PFT), exhibit pleiotropic effects that establish roles for protein prenylation in abscisic acid (ABA) signaling and meristem development. Here, we report the effects of T-DNA insertion mutations in the Arabidopsis GGB gene, which encodes the beta-subunit of protein geranylgeranyltransferase type I (PGGT I). Stomatal apertures of ggb plants were smaller than those of wild-type plants at all concentrations of ABA tested, suggesting that PGGT I negatively regulates ABA signaling in guard cells. However, germination of ggb seeds in response to ABA was similar to the wild type. Lateral root formation in response to exogenous auxin was increased in ggb seedlings compared to the wild type, but no change in auxin inhibition of primary root growth was observed, suggesting that PGGT I is specifically involved in negative regulation of auxin-induced lateral root initiation. Unlike era1 mutants, ggb mutants exhibited no obvious developmental phenotypes. However, era1 ggb double mutants exhibited more severe developmental phenotypes than era1 mutants and were indistinguishable from plp mutants lacking the shared alpha-subunit of PFT and PGGT I. Furthermore, overexpression of GGB in transgenic era1 plants partially suppressed the era1 phenotype, suggesting that the relatively weak phenotype of era1 plants is due to partial redundancy between PFT and PGGT I. These results are discussed in the context of Arabidopsis proteins that are putative substrates of PGGT I.
Pubmed ID 16183844
Journal Plant physiology
Volume 139
Issue 2
Pages 722-33
Publication date 2005 Oct
Num of phenotype gene 0