At5g50600 encodes a member of the short-chain dehydrogenase reductase superfamily with 11β- and 17β-hydroxysteroid dehydrogenase activities associated with Arabidopsis thaliana seed oil bodies - AgroParisTech Accéder directement au contenu
Article Dans Une Revue Biochimie Année : 2007

At5g50600 encodes a member of the short-chain dehydrogenase reductase superfamily with 11β- and 17β-hydroxysteroid dehydrogenase activities associated with Arabidopsis thaliana seed oil bodies

Sabine D’andrea
M. Canonge
  • Fonction : Auteur
A. Beopoulos
  • Fonction : Auteur
P. Jolivet
  • Fonction : Auteur
M. Miquel
  • Fonction : Auteur
L. Lepiniec
T. Chardot
  • Fonction : Auteur correspondant

Résumé

In a previous work, we presented evidence for the presence of a protein encoded by At5g50600 in oil bodies (OBs) from Arabidopsis thaliana [P. Jolivet, E. Roux, S. D'Andrea, M. Davanture, L. Negroni, M. Zivy, T. Chardot, Protein composition of oil bodies in Arabidopsis thaliana ecotype WS, Plant Physiol. Biochem. 42 (2004) 501-509]. Using specific antibodies and proteomic techniques, we presently confirm the existence of this protein, which is a member of the short-chain steroid dehydrogenase reductase superfamily. We have measured its activity toward various steroids (cholesterol, dehydroepiandrosterone, cortisol, corticosterone, estradiol, estrone) and NAD(P)(H), either within purified OBs or as a purified bacterially expressed chimera. Both enzymatic systems (OBs purified from A. thaliana seeds as well as the chimeric enzyme) exhibited hydroxysteroid dehydrogenase (HSD) activity toward estradiol (17beta-hydroxysteroid) with NAD+ or NADP+, NADP+ being the preferred cofactor. Low levels of activity were observed with cortisol or corticosterone (11beta-hydroxysteroids), but neither cholesterol nor DHEA (3beta-hydroxysteroids) were substrates, whatever the cofactor used. Similar activity profiles were found for both enzyme sources. Purified OBs were found to be also able to catalyze estrone reduction (17beta-ketosteroid reductase activity) with NADPH. The enzyme occurring in A. thaliana OBs can be classified as a NADP+-dependent 11beta-,17beta-hydroxysteroid dehydrogenase/17beta-ketosteroid reductase. This enzyme probably corresponds to AtHSD1, which is encoded by At5g50600. However, its physiological role and substrates still remain to be determined.

Dates et versions

hal-03659067 , version 1 (04-05-2022)

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Sabine D’andrea, M. Canonge, A. Beopoulos, P. Jolivet, M.A. Hartmann, et al.. At5g50600 encodes a member of the short-chain dehydrogenase reductase superfamily with 11β- and 17β-hydroxysteroid dehydrogenase activities associated with Arabidopsis thaliana seed oil bodies. Biochimie, 2007, 89 (2), pp.222-229. ⟨10.1016/j.biochi.2006.09.013⟩. ⟨hal-03659067⟩
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