Rv3723/LucA coordinates fatty acid and cholesterol uptake in Mycobacterium tuberculosis

Elife. 2017 Jun 27;6:e26969. doi: 10.7554/eLife.26969.


Pathogenic bacteria have evolved highly specialized systems to extract essential nutrients from their hosts. Mycobacterium tuberculosis (Mtb) scavenges lipids (cholesterol and fatty acids) to maintain infections in mammals but mechanisms and proteins responsible for the import of fatty acids in Mtb were previously unknown. Here, we identify and determine that the previously uncharacterized protein Rv3723/LucA, functions to integrate cholesterol and fatty acid uptake in Mtb. Rv3723/LucA interacts with subunits of the Mce1 and Mce4 complexes to coordinate the activities of these nutrient transporters by maintaining their stability. We also demonstrate that Mce1 functions as a fatty acid transporter in Mtb and determine that facilitating cholesterol and fatty acid import via Rv3723/LucA is required for full bacterial virulence in vivo. These data establish that fatty acid and cholesterol assimilation are inexorably linked in Mtb and reveals a key function for Rv3723/LucA in in coordinating thetransport of both these substrates.

Keywords: cholesterol; fatty acids; infectious disease; macrophages; microbiology; mycobacterium; pathogenesis; transport.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Biological Transport
  • Cells, Cultured
  • Cholesterol / metabolism*
  • Fatty Acids / metabolism*
  • Macrophages / microbiology
  • Membrane Transport Proteins / genetics
  • Membrane Transport Proteins / metabolism*
  • Mice, Inbred BALB C
  • Mutagenesis, Insertional
  • Mycobacterium tuberculosis / growth & development
  • Mycobacterium tuberculosis / metabolism*
  • Virulence


  • Bacterial Proteins
  • Fatty Acids
  • Membrane Transport Proteins
  • Cholesterol