A plastid envelope location of Arabidopsis ent-kaurene oxidase links the plastid and endoplasmic reticulum steps of the gibberellin biosynthesis pathway

Citation
Ca. Helliwell et al., A plastid envelope location of Arabidopsis ent-kaurene oxidase links the plastid and endoplasmic reticulum steps of the gibberellin biosynthesis pathway, PLANT J, 28(2), 2001, pp. 201-208
Citations number
29
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences","Animal & Plant Sciences
Journal title
PLANT JOURNAL
ISSN journal
0960-7412 → ACNP
Volume
28
Issue
2
Year of publication
2001
Pages
201 - 208
Database
ISI
SICI code
0960-7412(200110)28:2<201:APELOA>2.0.ZU;2-K
Abstract
We have used fusions of gibberellin biosynthesis enzymes to green fluoresce nt protein (GFP) to determine the subcellular localization of the early ste ps of the pathway. Gibberellin biosynthesis from geranylgeranyl diphosphate is catalysed by enzymes of the terpene cyclase, cytochrome P450 monooxygen ase and 2-oxoglutarate-dependent dioxygenase classes. We show that the N-te rminal presequences of the Arabidopsis thaliana terpene cyclases copalyl di phosphate synthase (AtCPS1) and entkaurene synthase (AtKS1) direct GFP to c hloroplasts; in transient assays following microprojectile bombardment of t obacco leaves. The AtKS1-GFP fusion is also imported by isolated pea chloro plasts. The N-terminal portion of the cytochrome P450 protein ent-kaurene o xidase (AtKO1) directs GFP to chloroplasts in tobacco leaf transient assays , Chloroplast import assays with S-35-labelled AtKO1 protein show that it i s targeted to the outer face of the chloroplast envelope. The leader sequen ces of the two ent-kaurenoic acid oxidases (AtKAO1 and AtKAO2) from Arabido psis direct GFP to the endoplasmic reticulum. These data suggest that the A tKO1 protein links the plastid- and endoplasmic reticulum-located steps of the gibberellin biosynthesis pathway by association with the outer envelope of the plastid.