The Arabidopsis GA1 Locus Encodes the Cyclase ent-Kaurene Synthetase A of Gibberellin Biosynthesis

Sun, Tai‐Ping; Kamiya, Yûji

doi:10.2307/3869986

Cited by 125 publications

(174 citation statements)

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“…Fungi, in particular, were found to possess bi-functional diterpene cyclases that can convert geranylgeranyl diphosphate into ent-kaurene [49,61]. In contrast, in plants, ent-kaurene is synthesized from geranylgeranyl diphosphate via copalyl diphosphate in a two-step cyclization that is catalyzed by two distinct enzymes, copalyl diphosphate synthase [47] and entkaurene synthase [48] (Fig. 3).…”

Section: Biosynthesis Of Isoprenoidsmentioning

confidence: 99%

Studies on Biosynthetic Genes and Enzymes of Isoprenoids Produced by Actinomycetes

Dairi

2005

J Antibiot

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Most Streptomyces strains are equipped with only the 2-C-methyl-D-erythritol 4-phosphate (MEP) pathway for the formation of isopentenyl diphosphate, a common precursor of isoprenoids. In addition to this pathway, some Streptomyces strains possess the mevalonate (MV) pathway via which isoprenoid antibiotics are produced. We have recently cloned and analyzed the MV pathway gene clusters and their flanking regions from terpentecin, BE-40644, and furaquinocin A producers. All these clusters contained genes coding for mevalonate kinase, mevalonate diphosphate decarboxylase, phosphomevalonate kinase, type 2 IPP isomerase, HMGCoA reductase, and HMG-CoA synthase. The order of each of the open reading frames (ORFs) is also the same, and the respective homologous ORFs show more than 70% amino acid identity with each other. In contrast to these conservative gene organizations, the biosynthetic genes of terpentecin, BE-40644, and furaquinocin A were located just upstream and/or downstream of the MV pathway gene cluster. These facts suggested that all the actinomycete strains possessing both the MV and MEP pathways produce isoprenoid compounds and the biosynthetic genes of one of these isoprenoids usually exist adjacent to the MV pathway gene cluster. Therefore, when the presence of the MV cluster is detected by molecular genetic techniques, isoprenoids may be produced by the cultivation of these actinomycete strains. During the course of these studies, we identified diterpene cyclases possessing unique primary structures that differ from those of eukaryotes and catalyze unique reactions.Keywords isoprenoid, mevalonate pathway, biosynthesis, cyclase, Actinomycetes IntroductionActinomycete strains usually produce a number of secondary metabolites that often possess pharmaceutical activities. Therefore, for a long time, the strains have been used for many screenings to find novel, medically useful compounds. Consequently, more than 60 percent of the known antibiotics, including not only antibacterial antibiotics but also bioactive microbial compounds, have been reported to be produced by actinomycetes [1]. Presently, such pharmaceutically important, novel compounds can be found in the culture broth of actinomycete strains by screening rare actinomycetes, developing new screening strategies, employing sensitive assay methods for the detection of low concentrations of antibiotics, etc. However, sometimes, "semi-new antibiotics"-derivatives of known antibiotics-were isolated; discovering novel antibiotics every year became very difficult.In the past two decades, recombinant DNA technology has come into play in this field. Gene clusters encoding many natural products have been cloned and characterized. Moreover, whole-genome sequencing has uncovered hundreds of candidates for secondary metabolic pathways. Among them, the biosynthetic machinery of nonribosomal peptide and polyketide natural products has been extensively investigated [2ϳ7]. Recent progress in the application of combinatorial biosynthesis methods to these bi...

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Section: Biosynthesis Of Isoprenoidsmentioning

confidence: 99%

Studies on Biosynthetic Genes and Enzymes of Isoprenoids Produced by Actinomycetes

Dairi

2005

J Antibiot

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“…In addition to the photosynthetic pigments, both GAs and ABA are important chemical molecules synthesized from the plastidial geranyl geranyl diphosphate (GGPP) precursor, which is derived from IPP and DMAPP of the MEP pathway [8,9,28,29]. The biosynthetic pathways for GA and ABA have been well documented [7].…”

Section: Introductionmentioning

confidence: 99%

Disruption of the 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) gene results in albino, dwarf and defects in trichome initiation and stomata closure in Arabidopsis

Xing

Miao

et al. 2010

Cell Res

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1-Deoxy-d-xylulose-5-phosphate reductoisomerase (DXR) is an important enzyme involved in the 2-C-methyl-d-erythritol-4-phosphate (MEP) pathway which provides the basic five-carbon units for isoprenoid biosynthesis. To investigate the role of the MEP pathway in plant development and metabolism, we carried out detailed analyses on a dxr mutant (GK_215C01) and two DXR transgenic co-suppression lines, OX-DXR-L2 and OX-DXR-L7. We found that the dxr mutant was albino and dwarf. It never bolted, had significantly reduced number of trichomes and most of the stomata could not close normally in the leaves. The two co-suppression lines produced more yellow inflorescences and albino sepals with no trichomes. The transcription levels of genes involved in trichome initiation were found to be strongly affected, including GLABRA1, TRANSPARENT TESTA GLABROUS 1, TRIPTYCHON and SPINDLY, expression of which is regulated by gibberellic acids (GAs). Exogenous application of GA 3 could partially rescue the dwarf phenotype and the trichome initiation of dxr, whereas exogenous application of abscisic acid (ABA) could rescue the stomata closure defect, suggesting that lower levels of both GA and ABA contribute to the phenotype in the dxr mutants. We further found that genes involved in the biosynthetic pathways of GA and ABA were coordinately regulated. These results indicate that disruption of the plastidial MEP pathway leads to biosynthetic deficiency of photosynthetic pigments, GAs and ABA, and thus the developmental abnormalities, and that the flux from the cytoplasmic mevalonate pathway is not sufficient to rescue the deficiency caused by the blockage of the plastidial MEP pathway. These results reveal a critical role for the MEP biosynthetic pathway in controlling the biosynthesis of isoprenoids.

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“…Furthermore, the severity of the phenotypic defects observed in gid1a-1 gid1b-1 gid1c-1 demonstrate that the role of GA signaling in promoting Arabidopsis growth and development is even greater than previously described. In Arabidopsis, a single gene encodes ent-copalyl diphosphate synthase (CPS), an enzyme that catalyzes the first committed step of GA biosynthesis (Sun and Kamiya, 1994). The GA-deficient phenotype of the ga1-3 Figure 6.…”

Section: The Gid1 Triple Mutant Displays Severe Growth Defectsmentioning

confidence: 99%

Genetic Characterization and Functional Analysis of the GID1 Gibberellin Receptors inArabidopsis

et al. 2006

Self Cite

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We investigated the physiological function of three Arabidopsis thaliana homologs of the gibberellin (GA) receptor GIBBERELLIN-INSENSITIVE DWARF1 (GID1) by determining the developmental consequences of GID1 inactivation in insertion mutants. Although single mutants developed normally, gid1a gid1c and gid1a gid1b displayed reduced stem height and lower male fertility, respectively, indicating some functional specificity. The triple mutant displayed a dwarf phenotype more severe than that of the extreme GA-deficient mutant ga1-3. Flower formation occurred in long days but was delayed, with severe defects in floral organ development. The triple mutant did not respond to applied GA. All three GID1 homologs were expressed in most tissues throughout development but differed in expression level. GA treatment reduced transcript abundance for all three GID1 genes, suggesting feedback regulation. The DELLA protein REPRESSOR OF ga1-3 (RGA) accumulated in the triple mutant, whose phenotype could be partially rescued by loss of RGA function. Yeast two-hybrid and in vitro pull-down assays confirmed that GA enhances the interaction between GID1 and DELLA proteins. In addition, the N-terminal sequence containing the DELLA domain is necessary for GID1 binding. Furthermore, yeast three-hybrid assays showed that the GA-GID1 complex promotes the interaction between RGA and the F-box protein SLY1, a component of the SCF SLY1 E3 ubiquitin ligase that targets the DELLA protein for degradation.

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The Arabidopsis GA1 Locus Encodes the Cyclase ent-Kaurene Synthetase A of Gibberellin Biosynthesis

Cited by 125 publications

References 10 publications

Studies on Biosynthetic Genes and Enzymes of Isoprenoids Produced by Actinomycetes

Studies on Biosynthetic Genes and Enzymes of Isoprenoids Produced by Actinomycetes

Disruption of the 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR) gene results in albino, dwarf and defects in trichome initiation and stomata closure in Arabidopsis

Genetic Characterization and Functional Analysis of the GID1 Gibberellin Receptors inArabidopsis

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