Plant Molecular Biology

, Volume 68, Issue 6, pp 571–583

Arabidopsis acyl-CoA-binding proteins ACBP4 and ACBP5 are subcellularly localized to the cytosol and ACBP4 depletion affects membrane lipid composition

  • Shi Xiao
  • Hong-Ye Li
  • Jiao-Ping Zhang
  • Suk-Wah Chan
  • Mee-Len Chye
Article

DOI: 10.1007/s11103-008-9392-7

Cite this article as:
Xiao, S., Li, HY., Zhang, JP. et al. Plant Mol Biol (2008) 68: 571. doi:10.1007/s11103-008-9392-7

Abstract

In Arabidopsis thaliana, acyl-CoA-binding proteins (ACBPs) are encoded by six genes, and they display varying affinities for acyl-CoA esters. Recombinant ACBP4 and ACBP5 have been shown to bind oleoyl-CoA esters in vitro. In this study, the subcellular localizations of ACBP4 and ACBP5 were determined by biochemical fractionation followed by western blot analyses using anti-ACBP4 and anti-ACBP5 antibodies and immuno-electron microscopy. Confocal microscopy of autofluorescence-tagged ACBP4 and ACBP5, expressed transiently in onion epidermal cells and in transgenic Arabidopsis, confirmed their expression in the cytosol. Taken together, ACBP4 and ACBP5 are available in the cytosol to bind and transfer cytosolic oleoyl-CoA esters. Lipid profile analysis further revealed that an acbp4 knockout mutant showed decreases in membrane lipids (digalactosyldiacylglycerol, monogalactosyldiacylglycerol, phosphatidylcholine, phosphatidylethanolamine and phosphatidylinositol) while acbp4-complemented lines attained levels similar to wild type, suggesting that ACBP4 plays a role in the biosynthesis of membrane lipids including galactolipids and phospholipids.

Keywords

Acyl-CoA-binding protein Autofluorescence-tagged protein Cytosol Galactolipids Lipid metabolism Phospholipids 

Abbreviations

ACBP

Acyl-coenzyme-A-binding protein

DGDG

Digalactosyldiacylglycerol

MGDG

Monogalactosyldiacylglycerol

PA

Phosphatidic acid

PC

Phosphatidylcholine

PE

Phosphatidylethanolamine

PI

Phosphatidylinositol

Copyright information

© Springer Science+Business Media B.V. 2008

Authors and Affiliations

  • Shi Xiao
    • 1
  • Hong-Ye Li
    • 1
  • Jiao-Ping Zhang
    • 1
  • Suk-Wah Chan
    • 1
  • Mee-Len Chye
    • 1
  1. 1.School of Biological SciencesThe University of Hong KongHong KongChina

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