Fatty Acid Biosynthesis in Mitochondria of Grasses

Malonyl-Coenzyme A Is Generated by a Mitochondrial-Localized Acetyl-Coenzyme A Carboxylase

verfasst von

Manfred Focke, Ellen Gieringer, Sabine Schwan, Lothar Jänsch, Stefan Binder, Hans Peter Braun

Abstract

We present biochemical evidence for the occurrence of a 250-kD multifunctional acetyl-coenzyme A carboxylase in barley (Hordeum vulgare) mitochondria. Organelles from 6-d-old barley seedlings were purified by differential centrifugation and Percoll density gradient centrifugation. Upon analysis by two-dimensional Blue-native (BN)/SDS-PAGE, an abundant 250-kD protein can be visualized, which runs at 500 kD on the native gel dimension. A similar 500-kD complex is present in etioplasts from barley. The mitochondrial 250-kD protein is biotinylated as indicated by specific reaction with an antibody directed against biotin. Peptide sequence analysis by electrospray ionization tandem mass spectrometry of the 250-kD proteins from both organellar fractions revealed amino acid sequences that are 100% identical to plastidic acetyl-coenzyme A carboxylase from wheat (Triticum aestivum). The 500-kD complex was also detected in wheat mitochondria, but is absent in mitochondrial fractions from Arabidopsis. Specific acetyl-coenzyme A carboxylation activity in barley mitochondria is higher than in etioplasts, suggesting an important role of mitochondria in fatty acid biosynthesis. Functional implications are discussed.

Organisationseinheit(en)

Institut für Pflanzengenetik

Externe Organisation(en)

Karlsruher Institut für Technologie (KIT)
Helmholtz-Zentrum für Infektionsforschung GmbH (HZI)
Universität Ulm

Typ

Artikel

Journal

Plant physiology

Band

133

Seiten

875-884

Anzahl der Seiten

10

ISSN

0032-0889

Publikationsdatum

10.2003

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Physiologie, Genetik, Pflanzenkunde

Elektronische Version(en)

https://doi.org/10.1104/pp.103.027375 (Zugang: Offen)