title: A Single Arabidopsis Gene Encodes Two Differentially Targeted Geranylgeranyl Diphosphate Synthase Isoforms.
abstract: A wide diversity of isoprenoids is produced in different plant compartments. Most groups of isoprenoids synthesized in plastids, and some produced elsewhere in the plant cell derive from geranylgeranyl diphosphate (GGPP) synthesized by GGPP synthase (GGPPS) enzymes. In Arabidopsis (Arabidopsis thaliana), five genes appear to encode GGPPS isoforms localized in plastids (two), the endoplasmic reticulum (two), and mitochondria (one). However, the loss of function of the plastid-targeted GGPPS11 isoform (referred to as G11) is sufficient to cause lethality. Here, we show that the absence of a strong transcription initiation site in the G11 gene results in the production of transcripts of different lengths. The longer transcripts encode an isoform with a functional plastid import sequence that produces GGPP for the major groups of photosynthesis-related plastidial isoprenoids. However, shorter transcripts are also produced that lack the first translation initiation codon and rely on a second in-frame ATG codon to produce an enzymatically active isoform lacking this N-terminal domain. This short enzyme localizes in the cytosol and is essential for embryo development. Our results confirm that the production of differentially targeted enzyme isoforms from the same gene is a central mechanism to control the biosynthesis of isoprenoid precursors in different plant cell compartments.
authors.affiliation: Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain (M.A.R.-S., M.V.B., D.M., B.L., M.R.-C.); and.|Plant Research International, 6700 AA Wageningen, The Netherlands (B.S., J.B.).
authors.forename: M Águila
authors.identifier: 0000-0002-2281-6700
authors.initials: MÁ
authors.lastname: Ruiz-Sola
authors.affiliation: Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain (M.A.R.-S., M.V.B., D.M., B.L., M.R.-C.); and.|Plant Research International, 6700 AA Wageningen, The Netherlands (B.S., J.B.).
authors.forename: M Victoria
authors.identifier: 0000-0002-3846-4885
authors.initials: MV
authors.lastname: Barja
authors.affiliation: Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain (M.A.R.-S., M.V.B., D.M., B.L., M.R.-C.); and.|Plant Research International, 6700 AA Wageningen, The Netherlands (B.S., J.B.).
authors.forename: David
authors.identifier: 0000-0002-5483-7223
authors.initials: D
authors.lastname: Manzano
authors.affiliation: Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain (M.A.R.-S., M.V.B., D.M., B.L., M.R.-C.); and.|Plant Research International, 6700 AA Wageningen, The Netherlands (B.S., J.B.).
authors.forename: Briardo
authors.identifier: 0000-0002-3727-1395
authors.initials: B
authors.lastname: Llorente
authors.affiliation: Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain (M.A.R.-S., M.V.B., D.M., B.L., M.R.-C.); and.|Plant Research International, 6700 AA Wageningen, The Netherlands (B.S., J.B.).
authors.forename: Bert
authors.initials: B
authors.lastname: Schipper
authors.affiliation: Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain (M.A.R.-S., M.V.B., D.M., B.L., M.R.-C.); and.|Plant Research International, 6700 AA Wageningen, The Netherlands (B.S., J.B.).
authors.forename: Jules
authors.initials: J
authors.lastname: Beekwilder
authors.affiliation: Program of Plant Metabolism and Metabolic Engineering, Centre for Research in Agricultural Genomics (CRAG) CSIC-IRTA-UAB-UB, Campus UAB Bellaterra, 08193 Barcelona, Spain (M.A.R.-S., M.V.B., D.M., B.L., M.R.-C.); and manuel.rodriguez@cragenomica.es.|Plant Research International, 6700 AA Wageningen, The Netherlands (B.S., J.B.) manuel.rodriguez@cragenomica.es.
authors.forename: Manuel
authors.identifier: 0000-0002-1280-2305
authors.initials: M
authors.lastname: Rodriguez-Concepcion
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism*; D000483:Alleles; D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D053898:Biosynthetic Pathways / Q000235:genetics; D057075:Enzyme Assays; D017343:Genes, Plant; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008798:Mevalonic Acid / Q000378:metabolism; D010641:Phenotype; D018087:Plastids / Q000378:metabolism; D014176:Protein Biosynthesis / Q000235:genetics; D012639:Seeds / Q000378:metabolism; D013347:Subcellular Fractions / Q000378:metabolism; D013729:Terpenes / Q000737:chemistry / Q000378:metabolism; D024363:Transcription Initiation Site
chemical_list: D029681:Arabidopsis Proteins; D007527:Isoenzymes; D013729:Terpenes; D019883:Alkyl and Aryl Transferases; C588179:GGPS1 protein, Arabidopsis; D008798:Mevalonic Acid