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Mammalian mitochondria contain a soluble acyl carrier protein

John E Cronan1, Ian M Fearnley, John E Walker

  • 1Medical Research Council Dunn Human Nutrition Unit, Hills Road, Cambridge CB2 2XY, United Kingdom. j-cronan@life.uiuc.edu

FEBS Letters
|August 20, 2005
PubMed

Insights

Mammalian mitochondria may synthesize fatty acids using a bacterial-like system. Researchers found the key acyl carrier protein (ACP) component, SDAP, in the soluble mitochondrial matrix, enabling fatty acid synthesis.

Area of Science:

  • Mitochondrial biology
  • Biochemistry
  • Fatty acid metabolism

Background:

  • Plant and fungal mitochondria possess bacterial-like type II fatty acid synthesis systems.
  • This system utilizes soluble proteins and acyl carrier protein (ACP) for fatty acid synthesis.
  • Mammalian mitochondria are suspected to synthesize fatty acids, but the ACP component was unconfirmed.

Purpose of the Study:

  • To investigate the presence and localization of the acyl carrier protein (ACP) in mammalian mitochondria.
  • To determine if ACP is available for fatty acid synthesis within the mitochondrial matrix.

Main Methods:

  • Subcellular fractionation of bovine heart mitochondria.
  • Analysis of the soluble (matrix) and membrane fractions.
  • Identification and characterization of the SDAP protein.

Main Results:

  • The study identified the succinate dehydrogenase assembly protein (SDAP) as the mitochondrial ACP.
  • Most SDAP was found in the soluble matrix fraction of bovine heart mitochondria.
  • This localization indicates SDAP is accessible for fatty acid synthesis intermediates.

Conclusions:

  • Bovine heart mitochondria contain a soluble ACP (SDAP) crucial for type II fatty acid synthesis.
  • This finding provides evidence for a functional bacterial-like fatty acid synthesis pathway in mammalian mitochondria.

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